BIBLIOGRAPHY APIDOS, JEROME I. APRIL...
BIBLIOGRAPHY
APIDOS, JEROME I. APRIL 2011. Life Cycle and Predation Rate of Black-
Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted Spider Mites (Tetranychus
urticae Koch). Benguet State University, La Trinidad, Benguet.
Adviser: Maria Ana C. Tanyag, MSc.
ABSTRACT
The study was conducted at the Mites Predatory Rearing House from December
2010 to March 2011, to determine the duration and morphological characteristics of the
different growth stages of black-banded wing thrips, determine the feeding and
oviposition behavior, fecundity and generate information on the rate of consumption of
the different growth stages and the host preference of the predatory stages of black-
banded wing thrips (Aelothrips sp.).
The developmental stages and duration of the different growth stages are as
follows: egg- 11.74 to 16.03 days with a mean of 14.51 ± 0.78 days, larva I: 4.80-7.89
days with a mean of 6.32 ± 0.52 days, larva II: 2.86-4.2 days with a mean of 3.76 ± 0.237
days, pupa I: 1.05-2.23 days with a mean of 1.71 ± 0.23 days, pupa II: 3.10-4.22 days
with a mean of 3.79 ± 0.20 days. The longevity of adult female was 25.87-33.91 days
with a mean of 29.58 ± 1.28 days.
The egg is transparent and kidney shape, 3-4 µm long and a width of 6-9 µm. The
larva I is whitish, 13-15 µm long and a width of 3.00 µm. The larval II is yellowish, 20-
24 µm long and a width of 5-7 µm. The pupa I is yellowish, with wing pads half of the
body, 29-33 µm long and a width of 7-8 µm. The pupa II is yellowish, with longer wing
pads than pupa I and antennae that is drown back over the prothorax with a 31-34 µm
long and a width of 8 µm. The adult thrips is yellowish with red eyes, black head, white
prothorax, black mesothorax and metathorax and wings and abdomen with black and
white bands. The body length is 34-42 µm and a width of 8-10 µm.
The predatory stages catch and hold the prey with the aid of its forelegs and
mouthparts as they pierce the integument and suck the body contents of the prey by
means of their mandibulary and maxillary stylets aided by slight rotation of its head. On
the other hand, the female oviposit its egg into the leaf tissue through the use of its saw-
like ovipositor. It can lay as many as 15 to 31 eggs.
In terms of prey consumption, the larva I may consume an average of 10.2 eggs,
11.6 larvae, 5.8 nymphs and 2.6 adults. The larva II may consume an average of 32.2
eggs, 30.6 larvae, 20.2 nymphs and 8.8 adults. The adult stage may consume an average
of 342.6 eggs, 435 larvae, 255.6 nymphs and 126 adults.
The black-banded wing thrip larvae preferred both the eggs and larvae while the
adult preferred adult two-spotted spider mites.
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TABLE OF CONTENTS
Page
Bibliography……………………………………………………………………… i
Abstract…….…………………………………………………………………...
i
Table of Contents………………………………………………………………… iii
INTRODUCTION…………………………………………………………….…
1
REVIEW OF LITERATURE……………………………………………………. 3
METHODOLOGY……………………………………………….……………...
8
RESULTS AND DISCUSSION
Life History of Black-Banded
Wing Thrips (Aelothrips sp.)………...…………………………….…….. 16
Morphological
Characteristics
of the Different Growth Stages
of Black-Banded Wing Thrips
(Aeolothrips sp.)…………………………………………………………. 17
Feeding Behavior………………………………………………………… 21
Oviposition Behavior…………………………………………………….. 23
Fecundity ………………………………………………………………... 24
Total Consumption Rate of the
Different Growth Stages of Black-
Banded Wing Predatory Thrips
on the Different Growth Stages of
Two-Spotted Spider Mites……………………………………………….
24
Host Preference…………………………………………………………..
25
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary…………………………………………………………………. 27
Conclusion……………………………………………………………….. 28
iii
Recommendation………………………………………………………… 29
LITERATURE CITED…………………………………………………………...
30
APPENDICES……………………………………………………………………
31
iv
1
INTRODUCTION
Predatory thrips are common predators of spider mites and other insects. In our
locality, predatory thrips are common predators of spider mites. In 1995, Pecdasen
reported the presence of predatory thrips on the chrysanthemum. In 1996, Tanyag
identified two predators of two-spotted spider mites one of them was the six-spotted
thrips (Scolothrips saxmaculatus Pergande) which was also noted earlier by Pacdasen,
and a phytoseiid mite (Amblyseuis longispinosus Evans). In 2010, Das-ilen reported that
there was black-banded wing thrips (Aelothrips sp.) feeding on the two-spotted spider
mites on the cordyline plant.
The two-spotted spider mites attack hundreds of field and forage crops,
horticultural crops, ornamentals and weeds. In our locality two-spotted spider mite is the
mayor the pest of strawberry, rose plantations, chrysanthemum and leguminous crops.
The two-spotted spider mite adults and immature feed by rasping and sucking leaf
surfaces causing mottling, speckling, and bronzing of foliage. They commonly cover the
undersides of the leaves with fine webbing. Mites can float long distances on silken
threads they produced. Drought stressed and unthrifty plants are most subject to attack
(Hancook, 1999). Damaged fruits on the other hand, show yellowish or brownish spots,
dwarfed and cracked or distorted. As a result, the quality and yield are greatly reduced.
One of the characteristics of two-spotted spider mites is resistance to many
pesticides and often growers find them difficult to control.
In view to this problem the use of predators, parasitoids and entomophagous
microorganisms is being pursued as alternatives of using chemicals against crop pests.
One among the natural enemy of spotted-spider mites that was reported by Das-ilen
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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(2010) is the black-banded wing thrips (Aeolothrip sp.). However, its efficiency as
predator and information regarding on the developmental stages has never been
evaluated.
Thus, the result of the study may provide benchmark information on the predation
of black banded wing against the two-spotted spider mites. The research finding can be a
guide for the release of predatory thrips to control the injurious plant-feeding mites in the
field.
The study aimed to determine the duration and morphological characteristics of
the different growth stages of black-banded wing thrips, to determine the feeding and
oviposition behavior of the predator, fecundity and to generate information on the rate of
consumption of the different growth stages and the host preference of the predatory
stages of black-banded wing thrips (Aeolothrips sp.).
The study was conducted at the Mites Predatory Rearing House, Benguet State
University, La Trinidad, Benguet from December 2010 to March 2011.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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REVIEW OF LITERATURE
Predation
McGinley (2009) defined predation as an interaction between species in which
one species uses another species as food. Predation is a process of major importance in
influencing the distribution, abundance, and diversity of species in ecological
communities. Generally, successful predation leads to an increase in the population size
of predators and a decrease in population size of the prey.
Morphological Description and Life Cycle
of Two-Spotted Spider Mites
Egg. The eggs are laid singly and glued to undersurfaces. Eggs are laid any time
of the day and on any part of the whole leaf. The eggs are protected by translucent and
loosely built web suspended on the sides by thin threads. Newly laid eggs are translucent
but gradually become green colored then turn into shining red pearls when about to hatch.
The eyes of the developing embryo are reddish which can be seen through the translucent
egg shell as true red spots. The incubation ranged from 5.3 to 7.0 days with a mean of
5.90 ± 0.96 days (Tanyag, 1996).
Larva. The larvae are six-legged and feed upon hatching 10-12 days after egg
deposition. After a short feeding period of one to few days, they settle down and rest in
preparation for molting, Corpuz-Raros (1966), as cited by Tanyag (1996).
Protonymph.The protonymphs have four pair of legs. The body of protonymph is
light green to yellow green and later assumed light orange at quiescent stage. The body
was teardrop shape for males and ovate for females both which measures 8.0 to 8.5
micrometer long with a mean of 6.0 micrometer. The development ranged from 1.7 to 2.0
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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day with mean of 1.60 ± 0.35 for male and 2.0 to 3.39 days with a mean of 2.5 ± 0.31
days for female (Tanyag, 1996).
Deutonymph. This is second nymphal stage and much bigger than the
protonymph with four pairs of legs, Villegas (1964) as cited by Tanyag (1996). The
duration of male ranged from 1.5 to 2.2 days with mean of 1.67 days. The female ranged
from 2.0 to 4.0 days with a mean of 2.89 days (Tanyag, 1996).
Adult.The adult females are carmine red with dark marks at the back of sides that
are in most respects similar to the protonymph and deutonymph stages but are bigger and
broader. The adult males are slender and tapered idiosoma and lighter orange red. The
body appears teardrop-shaped and legs are proportionately longer. The development of
period of adult female ranged from 29.00 to 50.10 days with a mean of 32.50 ± 0.70 days
while adult male lived 20.00 to 34.80 days with mean of 23.10 ± 0.39 days (Tanyag,
1996).
The Thrips
The thrips are minute, slender and agile, rarely as long as one half inch. They live
in flowers or other parts of plants, feeding on the sap. Many are serious pests of fruits,
vegetables, flowers and field crops (Flint and Metcalf, 1962).
The mouthparts of thrips are unique, in some respects being intermediate between
the chewing and piercing-sucking types. The head bears well-developed compound eyes
and ocelli, and well developed but not extremely long antennae of six to nine segments.
The head capsule tapers downwards in a shape of a cone to a small mouth opening at its
lowermost part. Around this opening are two maxillary and smaller two labial palps as
are the bases of the maxillae and the labrum. The labrum is not elongated into a beak,
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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fused into the head cone as are the bases of the maxillae and labrum. In and out of this
funnel-like opening three jobbers or stylets operates by end thrusts to lacerate the
epidermis of the plant. The three stylets consist of the left mandible and two maxillae.
The eggs are laid on the tissue of the plant in some species, inserted into slits made by a
sharp ovipositor. Parthenogenesis is common. There is four or more nympal instar. The
last two do not feed and may be quite inactive - a foreshadowing of the complete
metamorphosis of the higher orders (Flint and Metcalf, 1962).
Distinguishing Feature of Banded Wing Thrips
(Aeolothrips fasciatus)
Banded wing thrips is black with three broad white bands on each forewing. Both
sexes are with complete banded wings, median pale band shorter than distal dark band.
Body and legs brown, antennal segment III yellow with extreme apex dark.Head and
pronotum with no long setae. Fore tarsus apically with stout recurved ventral hamus.
Antennae 9-segmented III long and slender with linear sensorium scarcely 0.3 as long as
segment, IV with sensorium almost 0.5 as long as segment and curved distally; segment
V – IX forming a single unit with V about the same length as VI – IX. Abdominal tergite
X with pair of very small trichobothria. Marginal setae on sternites arising at or close to
margin; sternite VII supernumerary paired setae arising well in front of margin. Male
tergite IV and V sometimes with very small paired dorsal tubercles; setae at base of
bifurcate claspers on tergite IX much longer than clasper, with no stout curved seta lateral
to claspers; antennal segment III almost fuscous rather than yellow, but abdominal
segments III – V sometimes paler than II and V (University of California, 2008).
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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Life History of Aeolothrips sp.
In 2009, Barbara made observations on the development of banded thrips
(Aeolothrips intermedius) under laboratory conditions with average temperatures of 23
±oC and 27±oC. It was observed that the duration of embryonic development was 6.8 and
3.7 day; duration of the first larval instars was 3.2 days and 2.4 days; duration of second
instars was 5.4 and 4.1 days and finally, duration of the pre-pupa and pupa was totally 6.2
days and 5.6 days. The life cycle duration (egg-adult) was 21.6 ± 2.2 days and 15.7 ±1.6
days.
Studies on Predatory Thrips
In 1995, Pecdasen studied the biology of mites on the chrysanthemum and
reported the presence of predatory thrips. In 1996, Tanyag studied the biology and
abundance of the red spider mites on strawberry. She identified two predators; one of
them was the Six-spotted thrips (Scolothrips saxmaculatus Pergande) which was also
noted earlier by Pacdasen, and a phytoseiid mite (Amblyseuis longispinosus Evans). The
result of their preliminary trials under laboratory condition showed that the larval and
adult stages of the thrips preferred the egg of spider mites than nymph and adult.
In 1998, Layao studied the voracity of predatory thrips (Scolothrips saxmaculatus
Pergande) on red spider mites (Tetranychus kansawai kishida) and found out that the first
instar thrips can consume 54.00 eggs, 27 nymphs and 18.67 adults while the second instar
can consume 66.29 eggs, 38.11 nymph and 28.15 adults.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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Searching Behavior and Feeding Behavior
Predatory Thrips (Scolothrips
saxmaculatus Pergande)
In 1998, Layao reported that larval instars of predatory thrips (Scolothrips
saxmaculatus Pergande) find their prey by random searching and recognized their prey
upon contact or very near to the prey. The thrips catch and hold the prey through forelegs
and mouthparts and pierce the integument then suck the body contents of the prey by
means of their mandibulary and maxillary stylets aided by slight rotation of its head.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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METHODOLOGY
Materials
The important materials used in the study were strawberry leaves, plastic pots,
plastic cups, cotton, fine forceps, scissor, dissecting microscope, magnifying glass, ocular
micrometer, camel brush, pen, digital camera, strawberry runners and watering can.
Propagation and Maintenance
of the Host Plants
Strawberry runners were grown on potted soil under greenhouse condition. One
strawberry runner was transplanted in a 6.5 inch diameter plastic pot. All necessary
cultural methods were employed except application of insecticides to encourage mites
and black-banded wing thrips.
Collection and Culture of Prey
Cassava and strawberry leaves infested with two-spotted spider mites in the field
were collected and brought to the laboratory for verification. The leaves were examined
with the aid of microscope. After verification, the two-spotted spider mites were
introduced into the potted strawberry with four true leaves. The two-spotted mites were
allowed to multiply until enough specimens are available. This served as the source of
prey for the duration of the study.
Collection and Culture of Predator
Black-banded wing thrips was collected from four o’clock flower (Mirabilis
jalapa) plant at the Research Extension Office, Benguet State University (Figure 1). The
identification of predatory thrips was made when there are thrips directly striking on the
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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Figure 1. The four o’clock flower (Mirabilis jalapa)
two-spotted spider mites on the o’clock leaves through the use of magnifying. The leaves
were excised and brought to laboratory for further identification with the aid of
microscope. The predatory thrips were reared on excised strawberry leaves with prey
under laboratory condition until enough specimens can be harvested.
Life History of the Black
Banded Wing Thrips
Healthy and succulent leaves of strawberry were used as host plant of two-spotted
spider mites and predatory thrips. The leaves were cut into disc with a diameter of two
cm. The leaf disc was cleaned first with the used of camel brush to remove the debris
including unwanted insects and mites. The leaf disc was placed individually on top of
water-soak cotton inside the plastic cup to retain the freshness of the leaf (Figure 2). The
leaf disc was replaced when necessary.
Duration of development. One adult female black banded wing thrips was
transferred to each leaf disc for laying. The adult females were provided with different
stages of prey. The disc containing the adult female was checked for every five minutes
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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Figure 2. Plastic cup with leaf disc used in studying the
life history of black-banded wing thrips
to monitor if the thrips was laying. Spotted adult female inserting its ovipositor into the
leaf tissue was observed until it removed its ovipositor into the leaf. After the female
thrips removed its ovipositor the time was noted and recorded. The adult female was
removed from the leaf disc after it laid its egg. The egg was confirmed by dissecting the
leaf through the use of fine forceps. The exposed egg was observed daily to monitor the
emergence of larva. The newly emerge larva was provided with different stages of prey.
Daily observation was done to monitor the duration of development of larva to pupa and
pupa to adult.
Five individuals were observed. The duration of development was counted per
hour and converted to days. All observations were done under dissecting microscope.
Morphological descriptions. At every sample of banded wing thrips development
a representative sample of the specimen was observed under a dissecting microscope to
determine the morphological characteristics. Observations were focused on the color,
shape and size of each developmental stage. Body of the thrips was measured from the
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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head up to the tip of abdomen. Body width was measured on the widest part of the
abdominal region with the use of ocular micrometer.
Feeding Behavior
Two–spotted spider mites as prey were introduced to the excised strawberry leaf
and followed by the predator. Microscope and digital camera were used in observing and
recoding how the predator consumed its prey.
Oviposition Behavior
The oviposition behavior of female black-banded wing thrips was observed. The
predators were provided with prey. Microscope and digital camera were used in
recording their behavior, respectively.
Fecundity
Newly emerged adult female black-banded wing thrips was reared on the excised
strawberry leaf and allowed to lay its egg. The predator was provided with different
stages of prey. The egg was determined when scar or marking on the leaf caused by the
saw-like ovipostitor of female as shown in Figure 3. The egg was confirmed by
dissecting the leaf with the aid of fine forceps. The eggs were counted and noted.
Observations were done using dissecting microscope.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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Figure 3. The scar made by the saw-like ovipositor
Predation Test
Fifty eggs, 50 larvae, 50 nymphs and 50 adults of two-spotted spider mites were
transferred separately into each leaf disc with the aid of camel brush. This was followed
by the introduction of one predatory stage of black-banded wing thrips. The set-up of the
study was considered as the predation of larvae and adult on eggs, larvae, nymphs and
adult of two-spotted spider mites.
The determination of consumed prey was done 24 hours after the introduction of
prey. The number of the prey that was consumed per day by the first and second instars
larvae and adult was recorded. After counting each consumption sufficient number of
preys was added to the discs to maintain the preys number (50). The total number of prey
that was consumed by the first and second instars larvae and adult were recorded.
Microscope was used in determining the number of the preys that was consumed by the
predator.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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Experimental Design for the Predation Test
The study was arranged in completely randomized design (CRD) and it was
replicated in five times. The treatments were as follows:
Treatments
T1 = Larva I
T2 = Larva II
T3 = Adult
Host Preference
Five different stages of two-spotted spider mites were transferred into a leaf disc
followed by the introduction of one predatory stage of the black-banded wing thrips at the
center with the aid of camel brush (Figure 4). When the predator consumed one prey the
predator was removed then another new predator of similar age was introduced. The
eaten or consumed prey was replenished. This was done until 30 predators were
introduced. The prey that was eaten was recorded. The determination of the host
preference of the predatory stages of thrips was done though percentage. The higher the
percentage of prey consumed was considered as the most preferred by the predatory stage
of thrips.
All observations were done under dissecting microscope.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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Red = Egg
Blue = Larva
Green =Nymph
Black = Adult
Yellow = Dropping point of the
predator
Figure 4. Arrangement of the different growth stages of prey and the dropping
point of the predator
Data Gathered
1. Duration of the different life stages of black-banded wing thrips.
a. Eggs. This refers to the incubation period of the egg.
b. Larvae. This refers to the duration of development of the larvae.
c. Pupa. This refers to the duration of development of pupa
d. Adult. This refers to the life span of adult female.
2. Morpological characteristics of the different growth stages of black-banded
wing thrips.
a. Eggs. This refers to the color, shape, length and width of the egg.
b. Larvae. This refers to the color, length and width of larvae.
c. Pupa. This refers to the color, length and of pupa.
d. Adult. This refers to the color, length and width of adult female.
3. Feeding behavior. This refers to the behavior of the predator when feeding.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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4. Oviposition behavior. This refers to the behavior of black-banded wing thrips
when laying.
5. Fecundity. This refers to the number of eggs laid by the adult female black-
banded wing thrips.
6. The number of prey that were consumed by the black-banded wing thrips. This
refers to the number of the different life stages of the prey that were consumed by the
different life stages of black-banded wing thrips.
7. Host preference. This refers to the most preferred developmental stages (egg,
larva, nymphs and adult) of the prey that was first consumed by the larvae and adult
black-banded wing thrips.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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RESULTS AND DISCUSSION
Life History of Black-Banded Wing Thrips
(Aelothrips sp.)
Duration of the Different Growth Stages
The mean duration of different stages of black-banded wing thrips is shown in
Table 1. It ranged from 49.42-68.48 days. Among the stages the longest in duration is the
adult and the least is the pupa I.
Egg. The duration of the egg stage ranged from11.74-16.03 days with a mean of
14.51 ± 0.78 days.
Larva
I. The larva I developed from 4.80-7.89 days with a mean of 6.32 ± 0.52
days.
Larva
II. The duration of development of the larva II range from 2.86-4.2 days
with a mean of 3.76 ± 0.23 days.
Pupa
I. The pupa I developed from 1.05-2.23 days with a mean of 1.71 ± 0.23
days.
Pupa
II. The pupa II developed from 3.10-4.22 days with a mean of 3.79 ± 0.20
days.
Adult. The longevity of adult female ranged from 25.87-33.91 days with a mean
of 29.58 ± 1.28 days.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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Table 1. Mean duration (days) of the different life stages of a female black-banded wing
thrips under room temperature
GROWTH STAGES
RANGE
MEAN
Egg
11.74-16.03
14.51 ± 0.78
Larva I
4.80-7.89
6.32 ± 0.52
Larva II
2.86-4.20
3.76 ± 0.23
Pupa I
1.05-2.23
3.79 ± 0.20
Pupa II
3.10-4.22
3.79 ± 0.20
Adult
25.87-33.91
29.58 ± 1.28
Total life span
49.42-68.48
59.64 ± 2.01
Morphological Characteristics of the Different
Growth Stages of Black-Banded Wing Thrips
(Aeolothrips sp.)
The body length and width of the different growth stages of black-banded wing
thrips are shown in Table 2.
Egg. The egg of black banded wing thrips is transparent when newly laid (Figure
5) and as the egg matures the red pigmented eyes is visible. The egg is kidney or bean
shaped. The egg was inserted into the leaf through the saw-like ovipositor of the female
thrips and laid singly on any part of the lower surface of the leaf.
The egg measures from 3-4 µm in length with a mean of 7.75 ± 0.31 µm and 6-9
µm in width with a mean of 3.63 ± 0.18 µm.
Larva I. After a few days of incubation period a six-legged larva hatched out from the
egg. The first instar is whitish when newly hatched as shown in Figure 6. It changed to
red orange or green after feeding on the body contents of spider mites (Figures 7 and 8).
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
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The first larval instar has piercing and sucking mouthparts, three pairs of slender legs,
slender body and no wing pads. The antenna is beat-like or moniliform.
The body length of the larva I measures from 13-15 µm in length with a mean of
14.25 ± 0.31 µm and 3.00 µm in width with a mean of 3.00 ± 0 µm.
Table 2. Length and width of the different growth stages of a female black-banded wing
thrips reared under room temperature
GROWTH
LENGTH (µm)
WIDTH (µm)
STAGES
RANGE
MEAN
RANGE
MEAN
Egg
6-9
7.75 ± 0.31
3-4
3.63 ± 0.18
Larva I
13-15
14.25 ± 0.31
3
3.00 ± 0
Larva II
20-24
21.75 ± 0.49
5-6
5.13 ± 0.12
Pupa I
29-33
31.25 ± 0.52
7-8
7.75 ± 0.16
Pupa II
31-34
33.00 ± 0.42
8
8.00 ± 0
Adult
34-42
39.88 ± 0.89
8-10
8.75 ± 0.25
Figure 5. Egg (40X)
Figure 6. Newly emerge larva I (40X)
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
19
Figure 7. Larva I (40X)
Figure 8. Larva I (40X)
Larva II. The second larval instar is yellowish when newly emerge as shown in
Figure 9. It changed to orange, red or green after feeding on the body content of the two-
spotted spider mites (Figure 10).
The second larval instar was the same as the first larval instar except of its size.
However, as it assumed its full size, its feeding activity gradually ceases. The larva
became restless and seeks a suitable place in preparation for the next stage.
The larva II measures from 20-24 µm in length with a mean of 21.75 ± 0.49 µm
and 5-7 µm in width with a mean of 5.13 ± 0.12 µm.
Pupa I. At the second molt, the pupa I emerged from the cast cuticle. In contrast
to the larva, the pupa I was inactive. It moves only when disturbed and prefers to stay in
leaf surface with webs of spider mites. The pupa I is yellowish, with wing pads half of
the body and does not feed (Figure 11). It moves only when disturbed and prefers to stay
in leaf surface with web of spider mites.
The pupa I measures from 29-33 µm in length with a mean of 31.25 ± 0.52 µm
and 7-8 µm in width with a mean of 7.75 ± 0.16 µm.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
20
Pupa II.The pupa II exhibits the same behavior as the pupa I. Morphologically it
differs from the pupa I in having longer wing pads, antennae turned back over the
prothorax and the body appendages assume adult proportions (Figure 12).
The pupa II measures from 31-34 µm in length with a mean of 33.00 ± 0.42 µm
and 8 µm in width with a mean of 8.75 ± 0.250 µm.
Adult. At the final molt, the adult emerged from the pupa. The body of the newly
emerged thrips is yellowish in color, the eyes are red, the wings are white (Figure 13).
After an hour the band of black and white is visible. The head is black, prothorax is
white, mesothorax and metathorax is black and the wings and abdomen are banded with
black and white colors (Figure 14).
The adult did not feed immediately. Only on the first day, after full hardening has
been achieved, it started to move about and search for the prey.
The adult female measures from 34-42 µm in length with a mean of 39.88 ± 0.89
µm and 8-10 µm in width with a mean of 8.75 ± 0.25 µm.
Figure 9. Newly emerge larva II (40X)
Figure 10. Mature larva II (40X)
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
21
Figure 12. Pupa II (40X)
Figure 11. Pupa I (40X)
Figure 13. Newly emerge adult (40X)
Figure 14. Adult (40X)
Feeding Behavior
The thrips uses its forelegs and mouthparts to catch and hold the prey (Figures 15-
18). They pierce the integument and suck the body contents of the prey by means of their
mandibulary and maxillary stylets aided by slight rotation of its head and wagging of
antennae.
The thrips inserts its stylets in any part of the body of the prey, but after it sucks
the one body part of its prey it will transfer its stylets to other body part of the prey.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
22
Figure 15. Larva I feeding on an egg
Figure 16. Larva I feeding on an
of two-spotted spider mites
adult of two-spotted
(40X)
spider mites (40X)
Figure 17. Larva II feeding on an egg
Figure 18. Adult feeding on an egg of
of two-spotted spider mites
two-spotted spider mites
(40X)
(40X)
The results collaborate with the report of Layao (1998) that the thrips catch and
hold its prey through their forelegs and mouth parts then pierce the integument through
their mandibulary and maxillary stylet aided by slight rotation of their heads.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
23
Oviposition Behavior
The oviposition behavior of black-banded wing thrips took place during the saw-
like ovipositor penetrates into the leaf tissue as shown in Figure 19. After penetration of
the ovipositor, there were three specific oviposition sequences observed; sawing of the
ovipositor, release of an egg into the leaf, and partial or complete withdrawal of the
ovipositor from the leaves.
The results coincided with the reports of Flint and Metcalf (1962) that some
species of thrips inserted their eggs into tissues of the plant through the sharp ovipositor
of the female black banded wing thrips.
Figure 19. Adult female black-banded wing thrips ovipositing its egg inside the leaf tissue
(Lateral view, 40X)
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
24
Fecundity
The total eggs laid by the female adult black-banded wing thrips is shown in
Table 3. A female adult can lay as many as 15 to 31 eggs.
Total Consumption Rate of the Different Growth
Stages of Black-Banded Wing Predatory Thrips
on the Different Growth Stages of
Two-Spotted Spider Mites
The total consumption rate of the different growth stages of black-banded wing
predatory thrips on the different growth stages of two-spotted spider mites is shown in
Table 4.
Statistical
analysis
revealed a highly significant number of the different stages of
spider mites consumed by the adult as compared to the consumption rate of larvae black-
banded thrips. The consumption rate of larvae on egg, larva and adult were not significant
except on the nymph which was highly significant.
The adult had the highest consumed egg with an average of 342.6 followed by
larva II with an average of 37.2 eggs and larva I with an average of 10.2 eggs,
respectively. The consumption rate of adult on larva had the highest with an average of
435 larvae followed by larva II with an average of 30.6 larvae and larva I with an average
Table 3. Total number of eggs laid by the adult female black-banded wing thrips
SAMPLE NO
TOTAL NO. OF EGGS LAID
1 31
2 15
3 26
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
25
Table 4. Total consumption rate of the different growth stages of black-banded wing
predatory thrips on the different growth stages of two-spotted spider mites
PREDATORY
GROWTH STAGE OF PREY
STAGE OF
Egg Larva
Nymph
Adult
THRIPS
Larva I
10.2b 11.6b 5.8c 2.6b
Larva II
37.2b 30.6b 20.2b 8.8b
Adult 342.6a 435a 255.6a 126a
*Means with the same letter in column are not significantly different at 5 % level by
DMRT
of 11.6 larvae. The adult had the highest total consumption rate on nymph with an
average of 255.6 nymphs followed by larva II with an average of 20.2 larvae and larva I
with an average of 5.8 nymphs. The adult had the highest total consumption on adult with
an average of 126 adult followed by larva II with an average of 8.8 adult and larva I with
an average of 2.6 nymphs, respectively.
Among the stages, the adult consumed more prey compared to the larva I and
larva II. This was probably because the adult is more active in searching and it requires
more prey. This implies that as banded wing thrips grows to another stage, the number of
consumed prey increases.
Host Preference
Table 5 shows the percent host preference of the different predatory stages of the
thrips on the different stages of prey.
Results show that the most preferred prey of larva I were both egg (33.3 %) and
larva (33.3 %) and the least preferred was the adult stage (6.67 %). The larva II prefers
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
26
larval stage (43.33 %) while the least preferred was the adult stage. Mean while, the adult
prefers the adult (53.33 %) and least preferred was the eggs (3.33%).
As it was observed that the larva I preferred the egg and larva, the probable reason
could be due to the less motile of larva and egg stage as compared to the larger and
motile nymphs and adults. Although there were some case that the larvae tried to catch
the larger prey however some prey tried to escape and the predator turned over. The
female adult preferred the adult stage of prey probable reason could be the adult want the
motile prey and it can get more food on the adult as compared to the immature.
Table 5. Host preference (%) of the different growth stages of black-banded wing
predatory thrips on the different growth stages of two-spotted spider mites
PREDATORY
GROWTH STAGE OF PREY
STAGE OF
Egg
Larva
Nymph
Adult
THRIPS
Larva I
33.33
33.33
26.67
6.67
Larva
II
26.67 43.33 26.67 3.33
Adult 3.33
16.67 26.67 53.33
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
27
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The life cycle and predation rate of black-banded wing thrips (Aelothrips sp.) on
spider mites (Tetranychus urticae Koch) was studied at the Mites Predatory Rearing
House from December 2010 to March 2011 to determine the duration and morphological
characteristics of the different growth stages of banded wing thrips, determine the feeding
and oviposition behavior, fecundity and generate information on the rate of consumption
of the different growth stages of black-banded wing thrips and the host preference of the
predatory stages of black-banded wing thrips.
The black-banded wing thrips underwent six developmental stages namely; egg,
larva I, larva II, pupa I, Pupa II and adult. The incubation period of egg was from11.74-
16.03 days with a mean of 14.51 ± 0.78 days. The larva I developed from 4.80-7.89 days
with a mean of 6.32 ± 0.52 days. The duration of development of the larva II range from
2.86-4.2 days with a mean of 3.76 ± 0.23 days. The pupa I developed from 1.05-2.23
days with a mean of 1.71 ± 0.23 days. The pupa II developed from 3.10-4.22 days with a
mean of 3.79 ± 0.20 days. The longevity of adult female ranged from 25.87-33.91 days
with a mean of 29.58 ± 1.28 days.
The egg is transparent, kidney shaped and measures from 3-4 µm in length and 6-
9 µm in width. The first instar is whitish and measures from 13-15 µm in length and 3.00
µm in width. The second larval instar is yellowish and measures from 20-24 µm in length
and 5-7 µm in width. The pupa I is yellowish, with wing pads half of the body and
measures from 29-33 µm in length and 7-8 µm in width. The pupa II is yellowish wing
longer wing pads, antennae turned back over the prothorax and measures from 31-34 µm
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
28
in length and 8 µm in width. The body of adult thrips is yellowish, red eyes, black head,
white prothorax, black mesothorax and metathorax and wings and abdomen with black
and white bands. The body length is 34-42 µm and 8-10 µm in width.
The predatory stages use its forelegs and mouthparts to catch and hold the prey.
They pierce the integument and suck the body contents of the prey by means of their
mandibulary and maxillary stylets aided by slight rotation of its head.
The female thrips oviposit its egg into the leaf tissue through the saw-like
ovipositor. It can lay as many as 15 to 31 eggs.
The larva I consumed an average of 10.2 eggs, 11.6 larvae, 5.8 nymphs and 2.6
adults. The larva II consumed an average of 32.2 eggs, 30.6 larvae, 20.2 nymphs and 8.8
adults. The adult banded wing thrips consumed an average of 342.6 eggs, 435 larvae,
255.6 nymphs and 126 adult.
The host preference of larva I were both egg and larva, the larva II prefers larva
while the adult prefers the adult two-spotted spider mites.
Conclusion
It is therefore concluded that the life cycle of black-banded wing thrips
(Aelothrips sp.) under laboratory condition ranges from 49.42-68.48 days. The predatory
stages catch and hold the prey with the aid of its forelegs and mouthparts as they pierce
the integument and suck the body contents of the prey by means of their mandibulary and
maxillary. The eggs are inserted into the leaf tissue through their saw-like ovipositor. The
adult female Aelothrips sp. can lay as many as 15 to 31 eggs. The thrips is effective
predator of two-spotted spider mites. The host preference of larva I are both egg and
larva, the larva II prefers larva while the adult prefers the adult two-spotted spider mites.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
29
Recommendation
It is recommended to study the field efficiency of black-banded wing thrips
against two-spotted spider mites.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
30
LITERATURE CITED
BARBARA, C. 2009. Notes on the presence of Aeolothrips intermedius in northwestern
(1): 107-112, 2009. ISSN 1721-886. Retrieved August 6, 2010 from
http://www.bulletinofinsectology.org/pdfarticles/vol62-2009-107-112conti.pdf
DAS-ILEN, G. S. 2010. Presencce of banded wing thrips in BSU, La Trinidad,
Benguet
(personal
interview).
HANCOOK, J. F.1999. Strawberries. CABI Publishing. New York, USA. Pp. 153-154.
LAYAO, J. A. 1998. Test on the voracity of predatory thrips (Scolothrips sexmaculatus
Pergande) on red spider mites. BS Thesis. BSU, La Trinidad,
Benguet. Pp.
14,
16.
MCGINLEY, M. 2009. Ecology, Animal Behavior (behavioral Ecology) and
Evolutionary Biology. December 28, 2009. Retrieved December 28, 2009 from
htt://www.eoearth.org/article/predation
FLINT, P. W. and METCALF, L. C. 1962. Destructive and Useful Insects “Their Habits
and Habitat and Control (4th ed.) New Delhi, India. Tata-McgraHill Publishing
Campany LTD. Pp. 211-212.
PECDASEN, F. B. 1996. Biology of spider mites (Tetranychus urticae Koch) feeding
on chrysanthemum. BS thesis. BSU. La Trinidad, Benguet. P. 27.
TANYAG, R C. 1996. Biology and abundance of red spider mites (Tetranychus
Kansawai
Kishida) on strawberry and its natural enemies and alternate host.
MS Thesis. Benguet State University, La Trinidad, Benguet. Pp. 23-27, 41.
UNIVERSITY OF CALIFORNIA. 2008. Distinguishing Feature of Banded Wing Thrips
Retrieved August 5, 2010, from htt://keys.
Lucidcentral.org/keysv3thrips of california/data/key/thysanoptera/Media/Htm/br
owse_species/Aeolothrips_fasciatus.htm
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
31
APPENDICES
Appendix Table 1. Duration (days) of the different growth stages of a female black-
banded wing thrips
STAGES OF
REPLICATION
PREDATOR
I II III
IV
TOTAL
V
MEAN
Egg
11.74 16.03 15.31 13.81 15.65 72.54 14.51
Larva
I
7.02 5.96 4.80 7.89 5.91 31.58 6.32
Larva
II
2.86 3.79 3.86 4.09 4.2 18.8 3.76
Pupa
I
1.05 2.23 1.66 1.38 2.22 8.54 1.71
Pupa
II
3.96 3.10 4.13 4.22 3.56 18.87 3.79
Adult
33.91 29.60 29.57 28.95 25.87 147.9 29.58
TOTAL
60.54 60.71 59.33 60.34
57.4 298.32 59.646
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
32
Appendix Table 2. Length (µm) of the different growth stages of a female black-banded
wing thrips
STAGE OF
REPLICATION
PREDATOR I II III IV V VI VII
TOTAL
VIII
MEAN
Egg
8 8 8 9 8 7 6 8 62 7.75
Larva
I
15 14 13 15 15 13 15 14 114 14.25
Larva
II 20 20 22 22 23 24 21 22 174 21.75
Pupa
I
31 32 32 29 33 30 30 33 250 31.25
Pupa
II
32 32 33 31 34 34 34 34 264 33
Adult
41 42 41 34 41 41 40 39 319 39.88
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
33
Appendix Table 3. Width (µm) of the different growth stages of a female black-banded
wing thrips
STAGE OF
REPLICATION
PREDATOR I II III IV V VI VII
TOTAL
VIII
MEAN
Egg
4 3 3 4 4 4 4 3 29 3.63
Larva
I 3 3 3 3 3 3 3 3 24 3
Larva
II 5 5 5 5 5 5 5 6 41 5.13
Pupa
I
8 8 7 8 8 8 7 8 62 7.75
Pupa
II 8 8 8 8 8 8 8 8 64 8
Adult 8
9
9
10
9
9
8
8
70
8.75
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
34
Appendix Table 4. Total consumption rate of the different growth stages of black-banded
wing predatory thrips on two-spotted spider mite egg
PREDATORY
REPLICATION
TOTAL MEAN
STAGE
I
II
III
IV
V
Larva I
10
8
13
9
11
51
10.2b
Larva
II 22 32 56 44 32 186
37.2b
Adult
371 354 421 220 347 1713
342.6a
ANOVA TABLE
SOURCE OF
TABULATED F
VARIANCE
DF
SS
MS
F VALUE
0.05 0.01
Treatment 2
340813.20 170406.60
89.56**
3.88
6.93
Error 12
22832.80
1902.73
TOTAL 14
363646.00
** - Highly significant CV = 33.55 %
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
35
Appendix Table 5. Total consumption rate of the different growth stages of black-banded
wing predatory thrips on two-spotted spider mite larva
PREDATORY
REPLICATION
STAGE
I
II
III
IV
V
TOTAL MEAN
Larva
I 12 13 7 13 13
58 11.6b
Larva
II 34 29 39 28 23 153
30.6b
Adult
246 442 379 511 600 2178
435.6a
ANOVA TABLE
SOURCE OF
TABULATED F
VARIANCE
DF
SS
MS
FVALUE
0.05 0.01
Treatment 2
573603.3333 286801.6667
47.75**
3.88
6.93
Error 12
72081.6000
6006.8000
TOTAL 14
645684.9333
** - Highly significant CV = 48.66 %
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
36
Appendix Table 6. Total consumption rate of the different growth stages of black-banded
wing predatory thrips on two-spotted spider mite nymph
PREDATORY
REPLICATION
STAGE
I
II
III
IV
V
TOTAL MEAN
Larva
I 7 6 5 6 5
29
5.8c
Larva
II 22 17 20 22 20 101
20.2b
Adult
245 267 256 258 252 1278
255.6a
ANOVA TABLE
SOURCE OF
TABULATED F
VARIANCE
DF
SS
MS
F VALUE
0.05 0.01
Treatment 2
196700.9333 98350.4667 4203.01**
3.88
6.93
Error 12
280.8000
23.4000
Total 14
196981.7333
** - Highly significant CV = 5.15 %
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
37
Appendix Table 7. Total consumption rate of the different growth stages of black-banded
wing predatory thrips on two-spotted spider mite adult
PREDATORY
REPLICATION
TOTAL MEAN
STAGE
I
II
III
IV
V
Larva
I 3 3 2 3 2
13
2.6b
Larva
II 6 13 9 8 8
44
8.8b
Adult 79
181
92
120
158
630
126a
ANOVA TABLE
SOURCE OF
TABULATED F
VARIANCE
DF
SS
MS
F VALUE
0.05 0.01
Treatment 2
48336.60
24168.20
38.78**
3.88
6.93
Error 12
7478.00
623.1667
Total 14
55814.40
** - Highly significant CV = 54.51 %
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
APIDOS, JEROME I. APRIL 2011. Life Cycle and Predation Rate of Black-
Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted Spider Mites (Tetranychus
urticae Koch). Benguet State University, La Trinidad, Benguet.
Adviser: Maria Ana C. Tanyag, MSc.
ABSTRACT
The study was conducted at the Mites Predatory Rearing House from December
2010 to March 2011, to determine the duration and morphological characteristics of the
different growth stages of black-banded wing thrips, determine the feeding and
oviposition behavior, fecundity and generate information on the rate of consumption of
the different growth stages and the host preference of the predatory stages of black-
banded wing thrips (Aelothrips sp.).
The developmental stages and duration of the different growth stages are as
follows: egg- 11.74 to 16.03 days with a mean of 14.51 ± 0.78 days, larva I: 4.80-7.89
days with a mean of 6.32 ± 0.52 days, larva II: 2.86-4.2 days with a mean of 3.76 ± 0.237
days, pupa I: 1.05-2.23 days with a mean of 1.71 ± 0.23 days, pupa II: 3.10-4.22 days
with a mean of 3.79 ± 0.20 days. The longevity of adult female was 25.87-33.91 days
with a mean of 29.58 ± 1.28 days.
The egg is transparent and kidney shape, 3-4 µm long and a width of 6-9 µm. The
larva I is whitish, 13-15 µm long and a width of 3.00 µm. The larval II is yellowish, 20-
24 µm long and a width of 5-7 µm. The pupa I is yellowish, with wing pads half of the
body, 29-33 µm long and a width of 7-8 µm. The pupa II is yellowish, with longer wing
pads than pupa I and antennae that is drown back over the prothorax with a 31-34 µm
long and a width of 8 µm. The adult thrips is yellowish with red eyes, black head, white
prothorax, black mesothorax and metathorax and wings and abdomen with black and
white bands. The body length is 34-42 µm and a width of 8-10 µm.
The predatory stages catch and hold the prey with the aid of its forelegs and
mouthparts as they pierce the integument and suck the body contents of the prey by
means of their mandibulary and maxillary stylets aided by slight rotation of its head. On
the other hand, the female oviposit its egg into the leaf tissue through the use of its saw-
like ovipositor. It can lay as many as 15 to 31 eggs.
In terms of prey consumption, the larva I may consume an average of 10.2 eggs,
11.6 larvae, 5.8 nymphs and 2.6 adults. The larva II may consume an average of 32.2
eggs, 30.6 larvae, 20.2 nymphs and 8.8 adults. The adult stage may consume an average
of 342.6 eggs, 435 larvae, 255.6 nymphs and 126 adults.
The black-banded wing thrip larvae preferred both the eggs and larvae while the
adult preferred adult two-spotted spider mites.
ii
TABLE OF CONTENTS
Page
Bibliography……………………………………………………………………… i
Abstract…….…………………………………………………………………...
i
Table of Contents………………………………………………………………… iii
INTRODUCTION…………………………………………………………….…
1
REVIEW OF LITERATURE……………………………………………………. 3
METHODOLOGY……………………………………………….……………...
8
RESULTS AND DISCUSSION
Life History of Black-Banded
Wing Thrips (Aelothrips sp.)………...…………………………….…….. 16
Morphological
Characteristics
of the Different Growth Stages
of Black-Banded Wing Thrips
(Aeolothrips sp.)…………………………………………………………. 17
Feeding Behavior………………………………………………………… 21
Oviposition Behavior…………………………………………………….. 23
Fecundity ………………………………………………………………... 24
Total Consumption Rate of the
Different Growth Stages of Black-
Banded Wing Predatory Thrips
on the Different Growth Stages of
Two-Spotted Spider Mites……………………………………………….
24
Host Preference…………………………………………………………..
25
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary…………………………………………………………………. 27
Conclusion……………………………………………………………….. 28
iii
Recommendation………………………………………………………… 29
LITERATURE CITED…………………………………………………………...
30
APPENDICES……………………………………………………………………
31
iv
1
INTRODUCTION
Predatory thrips are common predators of spider mites and other insects. In our
locality, predatory thrips are common predators of spider mites. In 1995, Pecdasen
reported the presence of predatory thrips on the chrysanthemum. In 1996, Tanyag
identified two predators of two-spotted spider mites one of them was the six-spotted
thrips (Scolothrips saxmaculatus Pergande) which was also noted earlier by Pacdasen,
and a phytoseiid mite (Amblyseuis longispinosus Evans). In 2010, Das-ilen reported that
there was black-banded wing thrips (Aelothrips sp.) feeding on the two-spotted spider
mites on the cordyline plant.
The two-spotted spider mites attack hundreds of field and forage crops,
horticultural crops, ornamentals and weeds. In our locality two-spotted spider mite is the
mayor the pest of strawberry, rose plantations, chrysanthemum and leguminous crops.
The two-spotted spider mite adults and immature feed by rasping and sucking leaf
surfaces causing mottling, speckling, and bronzing of foliage. They commonly cover the
undersides of the leaves with fine webbing. Mites can float long distances on silken
threads they produced. Drought stressed and unthrifty plants are most subject to attack
(Hancook, 1999). Damaged fruits on the other hand, show yellowish or brownish spots,
dwarfed and cracked or distorted. As a result, the quality and yield are greatly reduced.
One of the characteristics of two-spotted spider mites is resistance to many
pesticides and often growers find them difficult to control.
In view to this problem the use of predators, parasitoids and entomophagous
microorganisms is being pursued as alternatives of using chemicals against crop pests.
One among the natural enemy of spotted-spider mites that was reported by Das-ilen
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
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(2010) is the black-banded wing thrips (Aeolothrip sp.). However, its efficiency as
predator and information regarding on the developmental stages has never been
evaluated.
Thus, the result of the study may provide benchmark information on the predation
of black banded wing against the two-spotted spider mites. The research finding can be a
guide for the release of predatory thrips to control the injurious plant-feeding mites in the
field.
The study aimed to determine the duration and morphological characteristics of
the different growth stages of black-banded wing thrips, to determine the feeding and
oviposition behavior of the predator, fecundity and to generate information on the rate of
consumption of the different growth stages and the host preference of the predatory
stages of black-banded wing thrips (Aeolothrips sp.).
The study was conducted at the Mites Predatory Rearing House, Benguet State
University, La Trinidad, Benguet from December 2010 to March 2011.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
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REVIEW OF LITERATURE
Predation
McGinley (2009) defined predation as an interaction between species in which
one species uses another species as food. Predation is a process of major importance in
influencing the distribution, abundance, and diversity of species in ecological
communities. Generally, successful predation leads to an increase in the population size
of predators and a decrease in population size of the prey.
Morphological Description and Life Cycle
of Two-Spotted Spider Mites
Egg. The eggs are laid singly and glued to undersurfaces. Eggs are laid any time
of the day and on any part of the whole leaf. The eggs are protected by translucent and
loosely built web suspended on the sides by thin threads. Newly laid eggs are translucent
but gradually become green colored then turn into shining red pearls when about to hatch.
The eyes of the developing embryo are reddish which can be seen through the translucent
egg shell as true red spots. The incubation ranged from 5.3 to 7.0 days with a mean of
5.90 ± 0.96 days (Tanyag, 1996).
Larva. The larvae are six-legged and feed upon hatching 10-12 days after egg
deposition. After a short feeding period of one to few days, they settle down and rest in
preparation for molting, Corpuz-Raros (1966), as cited by Tanyag (1996).
Protonymph.The protonymphs have four pair of legs. The body of protonymph is
light green to yellow green and later assumed light orange at quiescent stage. The body
was teardrop shape for males and ovate for females both which measures 8.0 to 8.5
micrometer long with a mean of 6.0 micrometer. The development ranged from 1.7 to 2.0
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day with mean of 1.60 ± 0.35 for male and 2.0 to 3.39 days with a mean of 2.5 ± 0.31
days for female (Tanyag, 1996).
Deutonymph. This is second nymphal stage and much bigger than the
protonymph with four pairs of legs, Villegas (1964) as cited by Tanyag (1996). The
duration of male ranged from 1.5 to 2.2 days with mean of 1.67 days. The female ranged
from 2.0 to 4.0 days with a mean of 2.89 days (Tanyag, 1996).
Adult.The adult females are carmine red with dark marks at the back of sides that
are in most respects similar to the protonymph and deutonymph stages but are bigger and
broader. The adult males are slender and tapered idiosoma and lighter orange red. The
body appears teardrop-shaped and legs are proportionately longer. The development of
period of adult female ranged from 29.00 to 50.10 days with a mean of 32.50 ± 0.70 days
while adult male lived 20.00 to 34.80 days with mean of 23.10 ± 0.39 days (Tanyag,
1996).
The Thrips
The thrips are minute, slender and agile, rarely as long as one half inch. They live
in flowers or other parts of plants, feeding on the sap. Many are serious pests of fruits,
vegetables, flowers and field crops (Flint and Metcalf, 1962).
The mouthparts of thrips are unique, in some respects being intermediate between
the chewing and piercing-sucking types. The head bears well-developed compound eyes
and ocelli, and well developed but not extremely long antennae of six to nine segments.
The head capsule tapers downwards in a shape of a cone to a small mouth opening at its
lowermost part. Around this opening are two maxillary and smaller two labial palps as
are the bases of the maxillae and the labrum. The labrum is not elongated into a beak,
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fused into the head cone as are the bases of the maxillae and labrum. In and out of this
funnel-like opening three jobbers or stylets operates by end thrusts to lacerate the
epidermis of the plant. The three stylets consist of the left mandible and two maxillae.
The eggs are laid on the tissue of the plant in some species, inserted into slits made by a
sharp ovipositor. Parthenogenesis is common. There is four or more nympal instar. The
last two do not feed and may be quite inactive - a foreshadowing of the complete
metamorphosis of the higher orders (Flint and Metcalf, 1962).
Distinguishing Feature of Banded Wing Thrips
(Aeolothrips fasciatus)
Banded wing thrips is black with three broad white bands on each forewing. Both
sexes are with complete banded wings, median pale band shorter than distal dark band.
Body and legs brown, antennal segment III yellow with extreme apex dark.Head and
pronotum with no long setae. Fore tarsus apically with stout recurved ventral hamus.
Antennae 9-segmented III long and slender with linear sensorium scarcely 0.3 as long as
segment, IV with sensorium almost 0.5 as long as segment and curved distally; segment
V – IX forming a single unit with V about the same length as VI – IX. Abdominal tergite
X with pair of very small trichobothria. Marginal setae on sternites arising at or close to
margin; sternite VII supernumerary paired setae arising well in front of margin. Male
tergite IV and V sometimes with very small paired dorsal tubercles; setae at base of
bifurcate claspers on tergite IX much longer than clasper, with no stout curved seta lateral
to claspers; antennal segment III almost fuscous rather than yellow, but abdominal
segments III – V sometimes paler than II and V (University of California, 2008).
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Life History of Aeolothrips sp.
In 2009, Barbara made observations on the development of banded thrips
(Aeolothrips intermedius) under laboratory conditions with average temperatures of 23
±oC and 27±oC. It was observed that the duration of embryonic development was 6.8 and
3.7 day; duration of the first larval instars was 3.2 days and 2.4 days; duration of second
instars was 5.4 and 4.1 days and finally, duration of the pre-pupa and pupa was totally 6.2
days and 5.6 days. The life cycle duration (egg-adult) was 21.6 ± 2.2 days and 15.7 ±1.6
days.
Studies on Predatory Thrips
In 1995, Pecdasen studied the biology of mites on the chrysanthemum and
reported the presence of predatory thrips. In 1996, Tanyag studied the biology and
abundance of the red spider mites on strawberry. She identified two predators; one of
them was the Six-spotted thrips (Scolothrips saxmaculatus Pergande) which was also
noted earlier by Pacdasen, and a phytoseiid mite (Amblyseuis longispinosus Evans). The
result of their preliminary trials under laboratory condition showed that the larval and
adult stages of the thrips preferred the egg of spider mites than nymph and adult.
In 1998, Layao studied the voracity of predatory thrips (Scolothrips saxmaculatus
Pergande) on red spider mites (Tetranychus kansawai kishida) and found out that the first
instar thrips can consume 54.00 eggs, 27 nymphs and 18.67 adults while the second instar
can consume 66.29 eggs, 38.11 nymph and 28.15 adults.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
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Searching Behavior and Feeding Behavior
Predatory Thrips (Scolothrips
saxmaculatus Pergande)
In 1998, Layao reported that larval instars of predatory thrips (Scolothrips
saxmaculatus Pergande) find their prey by random searching and recognized their prey
upon contact or very near to the prey. The thrips catch and hold the prey through forelegs
and mouthparts and pierce the integument then suck the body contents of the prey by
means of their mandibulary and maxillary stylets aided by slight rotation of its head.
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METHODOLOGY
Materials
The important materials used in the study were strawberry leaves, plastic pots,
plastic cups, cotton, fine forceps, scissor, dissecting microscope, magnifying glass, ocular
micrometer, camel brush, pen, digital camera, strawberry runners and watering can.
Propagation and Maintenance
of the Host Plants
Strawberry runners were grown on potted soil under greenhouse condition. One
strawberry runner was transplanted in a 6.5 inch diameter plastic pot. All necessary
cultural methods were employed except application of insecticides to encourage mites
and black-banded wing thrips.
Collection and Culture of Prey
Cassava and strawberry leaves infested with two-spotted spider mites in the field
were collected and brought to the laboratory for verification. The leaves were examined
with the aid of microscope. After verification, the two-spotted spider mites were
introduced into the potted strawberry with four true leaves. The two-spotted mites were
allowed to multiply until enough specimens are available. This served as the source of
prey for the duration of the study.
Collection and Culture of Predator
Black-banded wing thrips was collected from four o’clock flower (Mirabilis
jalapa) plant at the Research Extension Office, Benguet State University (Figure 1). The
identification of predatory thrips was made when there are thrips directly striking on the
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Figure 1. The four o’clock flower (Mirabilis jalapa)
two-spotted spider mites on the o’clock leaves through the use of magnifying. The leaves
were excised and brought to laboratory for further identification with the aid of
microscope. The predatory thrips were reared on excised strawberry leaves with prey
under laboratory condition until enough specimens can be harvested.
Life History of the Black
Banded Wing Thrips
Healthy and succulent leaves of strawberry were used as host plant of two-spotted
spider mites and predatory thrips. The leaves were cut into disc with a diameter of two
cm. The leaf disc was cleaned first with the used of camel brush to remove the debris
including unwanted insects and mites. The leaf disc was placed individually on top of
water-soak cotton inside the plastic cup to retain the freshness of the leaf (Figure 2). The
leaf disc was replaced when necessary.
Duration of development. One adult female black banded wing thrips was
transferred to each leaf disc for laying. The adult females were provided with different
stages of prey. The disc containing the adult female was checked for every five minutes
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Figure 2. Plastic cup with leaf disc used in studying the
life history of black-banded wing thrips
to monitor if the thrips was laying. Spotted adult female inserting its ovipositor into the
leaf tissue was observed until it removed its ovipositor into the leaf. After the female
thrips removed its ovipositor the time was noted and recorded. The adult female was
removed from the leaf disc after it laid its egg. The egg was confirmed by dissecting the
leaf through the use of fine forceps. The exposed egg was observed daily to monitor the
emergence of larva. The newly emerge larva was provided with different stages of prey.
Daily observation was done to monitor the duration of development of larva to pupa and
pupa to adult.
Five individuals were observed. The duration of development was counted per
hour and converted to days. All observations were done under dissecting microscope.
Morphological descriptions. At every sample of banded wing thrips development
a representative sample of the specimen was observed under a dissecting microscope to
determine the morphological characteristics. Observations were focused on the color,
shape and size of each developmental stage. Body of the thrips was measured from the
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head up to the tip of abdomen. Body width was measured on the widest part of the
abdominal region with the use of ocular micrometer.
Feeding Behavior
Two–spotted spider mites as prey were introduced to the excised strawberry leaf
and followed by the predator. Microscope and digital camera were used in observing and
recoding how the predator consumed its prey.
Oviposition Behavior
The oviposition behavior of female black-banded wing thrips was observed. The
predators were provided with prey. Microscope and digital camera were used in
recording their behavior, respectively.
Fecundity
Newly emerged adult female black-banded wing thrips was reared on the excised
strawberry leaf and allowed to lay its egg. The predator was provided with different
stages of prey. The egg was determined when scar or marking on the leaf caused by the
saw-like ovipostitor of female as shown in Figure 3. The egg was confirmed by
dissecting the leaf with the aid of fine forceps. The eggs were counted and noted.
Observations were done using dissecting microscope.
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Figure 3. The scar made by the saw-like ovipositor
Predation Test
Fifty eggs, 50 larvae, 50 nymphs and 50 adults of two-spotted spider mites were
transferred separately into each leaf disc with the aid of camel brush. This was followed
by the introduction of one predatory stage of black-banded wing thrips. The set-up of the
study was considered as the predation of larvae and adult on eggs, larvae, nymphs and
adult of two-spotted spider mites.
The determination of consumed prey was done 24 hours after the introduction of
prey. The number of the prey that was consumed per day by the first and second instars
larvae and adult was recorded. After counting each consumption sufficient number of
preys was added to the discs to maintain the preys number (50). The total number of prey
that was consumed by the first and second instars larvae and adult were recorded.
Microscope was used in determining the number of the preys that was consumed by the
predator.
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Experimental Design for the Predation Test
The study was arranged in completely randomized design (CRD) and it was
replicated in five times. The treatments were as follows:
Treatments
T1 = Larva I
T2 = Larva II
T3 = Adult
Host Preference
Five different stages of two-spotted spider mites were transferred into a leaf disc
followed by the introduction of one predatory stage of the black-banded wing thrips at the
center with the aid of camel brush (Figure 4). When the predator consumed one prey the
predator was removed then another new predator of similar age was introduced. The
eaten or consumed prey was replenished. This was done until 30 predators were
introduced. The prey that was eaten was recorded. The determination of the host
preference of the predatory stages of thrips was done though percentage. The higher the
percentage of prey consumed was considered as the most preferred by the predatory stage
of thrips.
All observations were done under dissecting microscope.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
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Red = Egg
Blue = Larva
Green =Nymph
Black = Adult
Yellow = Dropping point of the
predator
Figure 4. Arrangement of the different growth stages of prey and the dropping
point of the predator
Data Gathered
1. Duration of the different life stages of black-banded wing thrips.
a. Eggs. This refers to the incubation period of the egg.
b. Larvae. This refers to the duration of development of the larvae.
c. Pupa. This refers to the duration of development of pupa
d. Adult. This refers to the life span of adult female.
2. Morpological characteristics of the different growth stages of black-banded
wing thrips.
a. Eggs. This refers to the color, shape, length and width of the egg.
b. Larvae. This refers to the color, length and width of larvae.
c. Pupa. This refers to the color, length and of pupa.
d. Adult. This refers to the color, length and width of adult female.
3. Feeding behavior. This refers to the behavior of the predator when feeding.
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4. Oviposition behavior. This refers to the behavior of black-banded wing thrips
when laying.
5. Fecundity. This refers to the number of eggs laid by the adult female black-
banded wing thrips.
6. The number of prey that were consumed by the black-banded wing thrips. This
refers to the number of the different life stages of the prey that were consumed by the
different life stages of black-banded wing thrips.
7. Host preference. This refers to the most preferred developmental stages (egg,
larva, nymphs and adult) of the prey that was first consumed by the larvae and adult
black-banded wing thrips.
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RESULTS AND DISCUSSION
Life History of Black-Banded Wing Thrips
(Aelothrips sp.)
Duration of the Different Growth Stages
The mean duration of different stages of black-banded wing thrips is shown in
Table 1. It ranged from 49.42-68.48 days. Among the stages the longest in duration is the
adult and the least is the pupa I.
Egg. The duration of the egg stage ranged from11.74-16.03 days with a mean of
14.51 ± 0.78 days.
Larva
I. The larva I developed from 4.80-7.89 days with a mean of 6.32 ± 0.52
days.
Larva
II. The duration of development of the larva II range from 2.86-4.2 days
with a mean of 3.76 ± 0.23 days.
Pupa
I. The pupa I developed from 1.05-2.23 days with a mean of 1.71 ± 0.23
days.
Pupa
II. The pupa II developed from 3.10-4.22 days with a mean of 3.79 ± 0.20
days.
Adult. The longevity of adult female ranged from 25.87-33.91 days with a mean
of 29.58 ± 1.28 days.
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Table 1. Mean duration (days) of the different life stages of a female black-banded wing
thrips under room temperature
GROWTH STAGES
RANGE
MEAN
Egg
11.74-16.03
14.51 ± 0.78
Larva I
4.80-7.89
6.32 ± 0.52
Larva II
2.86-4.20
3.76 ± 0.23
Pupa I
1.05-2.23
3.79 ± 0.20
Pupa II
3.10-4.22
3.79 ± 0.20
Adult
25.87-33.91
29.58 ± 1.28
Total life span
49.42-68.48
59.64 ± 2.01
Morphological Characteristics of the Different
Growth Stages of Black-Banded Wing Thrips
(Aeolothrips sp.)
The body length and width of the different growth stages of black-banded wing
thrips are shown in Table 2.
Egg. The egg of black banded wing thrips is transparent when newly laid (Figure
5) and as the egg matures the red pigmented eyes is visible. The egg is kidney or bean
shaped. The egg was inserted into the leaf through the saw-like ovipositor of the female
thrips and laid singly on any part of the lower surface of the leaf.
The egg measures from 3-4 µm in length with a mean of 7.75 ± 0.31 µm and 6-9
µm in width with a mean of 3.63 ± 0.18 µm.
Larva I. After a few days of incubation period a six-legged larva hatched out from the
egg. The first instar is whitish when newly hatched as shown in Figure 6. It changed to
red orange or green after feeding on the body contents of spider mites (Figures 7 and 8).
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The first larval instar has piercing and sucking mouthparts, three pairs of slender legs,
slender body and no wing pads. The antenna is beat-like or moniliform.
The body length of the larva I measures from 13-15 µm in length with a mean of
14.25 ± 0.31 µm and 3.00 µm in width with a mean of 3.00 ± 0 µm.
Table 2. Length and width of the different growth stages of a female black-banded wing
thrips reared under room temperature
GROWTH
LENGTH (µm)
WIDTH (µm)
STAGES
RANGE
MEAN
RANGE
MEAN
Egg
6-9
7.75 ± 0.31
3-4
3.63 ± 0.18
Larva I
13-15
14.25 ± 0.31
3
3.00 ± 0
Larva II
20-24
21.75 ± 0.49
5-6
5.13 ± 0.12
Pupa I
29-33
31.25 ± 0.52
7-8
7.75 ± 0.16
Pupa II
31-34
33.00 ± 0.42
8
8.00 ± 0
Adult
34-42
39.88 ± 0.89
8-10
8.75 ± 0.25
Figure 5. Egg (40X)
Figure 6. Newly emerge larva I (40X)
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Figure 7. Larva I (40X)
Figure 8. Larva I (40X)
Larva II. The second larval instar is yellowish when newly emerge as shown in
Figure 9. It changed to orange, red or green after feeding on the body content of the two-
spotted spider mites (Figure 10).
The second larval instar was the same as the first larval instar except of its size.
However, as it assumed its full size, its feeding activity gradually ceases. The larva
became restless and seeks a suitable place in preparation for the next stage.
The larva II measures from 20-24 µm in length with a mean of 21.75 ± 0.49 µm
and 5-7 µm in width with a mean of 5.13 ± 0.12 µm.
Pupa I. At the second molt, the pupa I emerged from the cast cuticle. In contrast
to the larva, the pupa I was inactive. It moves only when disturbed and prefers to stay in
leaf surface with webs of spider mites. The pupa I is yellowish, with wing pads half of
the body and does not feed (Figure 11). It moves only when disturbed and prefers to stay
in leaf surface with web of spider mites.
The pupa I measures from 29-33 µm in length with a mean of 31.25 ± 0.52 µm
and 7-8 µm in width with a mean of 7.75 ± 0.16 µm.
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Pupa II.The pupa II exhibits the same behavior as the pupa I. Morphologically it
differs from the pupa I in having longer wing pads, antennae turned back over the
prothorax and the body appendages assume adult proportions (Figure 12).
The pupa II measures from 31-34 µm in length with a mean of 33.00 ± 0.42 µm
and 8 µm in width with a mean of 8.75 ± 0.250 µm.
Adult. At the final molt, the adult emerged from the pupa. The body of the newly
emerged thrips is yellowish in color, the eyes are red, the wings are white (Figure 13).
After an hour the band of black and white is visible. The head is black, prothorax is
white, mesothorax and metathorax is black and the wings and abdomen are banded with
black and white colors (Figure 14).
The adult did not feed immediately. Only on the first day, after full hardening has
been achieved, it started to move about and search for the prey.
The adult female measures from 34-42 µm in length with a mean of 39.88 ± 0.89
µm and 8-10 µm in width with a mean of 8.75 ± 0.25 µm.
Figure 9. Newly emerge larva II (40X)
Figure 10. Mature larva II (40X)
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Figure 12. Pupa II (40X)
Figure 11. Pupa I (40X)
Figure 13. Newly emerge adult (40X)
Figure 14. Adult (40X)
Feeding Behavior
The thrips uses its forelegs and mouthparts to catch and hold the prey (Figures 15-
18). They pierce the integument and suck the body contents of the prey by means of their
mandibulary and maxillary stylets aided by slight rotation of its head and wagging of
antennae.
The thrips inserts its stylets in any part of the body of the prey, but after it sucks
the one body part of its prey it will transfer its stylets to other body part of the prey.
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Figure 15. Larva I feeding on an egg
Figure 16. Larva I feeding on an
of two-spotted spider mites
adult of two-spotted
(40X)
spider mites (40X)
Figure 17. Larva II feeding on an egg
Figure 18. Adult feeding on an egg of
of two-spotted spider mites
two-spotted spider mites
(40X)
(40X)
The results collaborate with the report of Layao (1998) that the thrips catch and
hold its prey through their forelegs and mouth parts then pierce the integument through
their mandibulary and maxillary stylet aided by slight rotation of their heads.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
23
Oviposition Behavior
The oviposition behavior of black-banded wing thrips took place during the saw-
like ovipositor penetrates into the leaf tissue as shown in Figure 19. After penetration of
the ovipositor, there were three specific oviposition sequences observed; sawing of the
ovipositor, release of an egg into the leaf, and partial or complete withdrawal of the
ovipositor from the leaves.
The results coincided with the reports of Flint and Metcalf (1962) that some
species of thrips inserted their eggs into tissues of the plant through the sharp ovipositor
of the female black banded wing thrips.
Figure 19. Adult female black-banded wing thrips ovipositing its egg inside the leaf tissue
(Lateral view, 40X)
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
24
Fecundity
The total eggs laid by the female adult black-banded wing thrips is shown in
Table 3. A female adult can lay as many as 15 to 31 eggs.
Total Consumption Rate of the Different Growth
Stages of Black-Banded Wing Predatory Thrips
on the Different Growth Stages of
Two-Spotted Spider Mites
The total consumption rate of the different growth stages of black-banded wing
predatory thrips on the different growth stages of two-spotted spider mites is shown in
Table 4.
Statistical
analysis
revealed a highly significant number of the different stages of
spider mites consumed by the adult as compared to the consumption rate of larvae black-
banded thrips. The consumption rate of larvae on egg, larva and adult were not significant
except on the nymph which was highly significant.
The adult had the highest consumed egg with an average of 342.6 followed by
larva II with an average of 37.2 eggs and larva I with an average of 10.2 eggs,
respectively. The consumption rate of adult on larva had the highest with an average of
435 larvae followed by larva II with an average of 30.6 larvae and larva I with an average
Table 3. Total number of eggs laid by the adult female black-banded wing thrips
SAMPLE NO
TOTAL NO. OF EGGS LAID
1 31
2 15
3 26
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
25
Table 4. Total consumption rate of the different growth stages of black-banded wing
predatory thrips on the different growth stages of two-spotted spider mites
PREDATORY
GROWTH STAGE OF PREY
STAGE OF
Egg Larva
Nymph
Adult
THRIPS
Larva I
10.2b 11.6b 5.8c 2.6b
Larva II
37.2b 30.6b 20.2b 8.8b
Adult 342.6a 435a 255.6a 126a
*Means with the same letter in column are not significantly different at 5 % level by
DMRT
of 11.6 larvae. The adult had the highest total consumption rate on nymph with an
average of 255.6 nymphs followed by larva II with an average of 20.2 larvae and larva I
with an average of 5.8 nymphs. The adult had the highest total consumption on adult with
an average of 126 adult followed by larva II with an average of 8.8 adult and larva I with
an average of 2.6 nymphs, respectively.
Among the stages, the adult consumed more prey compared to the larva I and
larva II. This was probably because the adult is more active in searching and it requires
more prey. This implies that as banded wing thrips grows to another stage, the number of
consumed prey increases.
Host Preference
Table 5 shows the percent host preference of the different predatory stages of the
thrips on the different stages of prey.
Results show that the most preferred prey of larva I were both egg (33.3 %) and
larva (33.3 %) and the least preferred was the adult stage (6.67 %). The larva II prefers
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
26
larval stage (43.33 %) while the least preferred was the adult stage. Mean while, the adult
prefers the adult (53.33 %) and least preferred was the eggs (3.33%).
As it was observed that the larva I preferred the egg and larva, the probable reason
could be due to the less motile of larva and egg stage as compared to the larger and
motile nymphs and adults. Although there were some case that the larvae tried to catch
the larger prey however some prey tried to escape and the predator turned over. The
female adult preferred the adult stage of prey probable reason could be the adult want the
motile prey and it can get more food on the adult as compared to the immature.
Table 5. Host preference (%) of the different growth stages of black-banded wing
predatory thrips on the different growth stages of two-spotted spider mites
PREDATORY
GROWTH STAGE OF PREY
STAGE OF
Egg
Larva
Nymph
Adult
THRIPS
Larva I
33.33
33.33
26.67
6.67
Larva
II
26.67 43.33 26.67 3.33
Adult 3.33
16.67 26.67 53.33
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
27
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The life cycle and predation rate of black-banded wing thrips (Aelothrips sp.) on
spider mites (Tetranychus urticae Koch) was studied at the Mites Predatory Rearing
House from December 2010 to March 2011 to determine the duration and morphological
characteristics of the different growth stages of banded wing thrips, determine the feeding
and oviposition behavior, fecundity and generate information on the rate of consumption
of the different growth stages of black-banded wing thrips and the host preference of the
predatory stages of black-banded wing thrips.
The black-banded wing thrips underwent six developmental stages namely; egg,
larva I, larva II, pupa I, Pupa II and adult. The incubation period of egg was from11.74-
16.03 days with a mean of 14.51 ± 0.78 days. The larva I developed from 4.80-7.89 days
with a mean of 6.32 ± 0.52 days. The duration of development of the larva II range from
2.86-4.2 days with a mean of 3.76 ± 0.23 days. The pupa I developed from 1.05-2.23
days with a mean of 1.71 ± 0.23 days. The pupa II developed from 3.10-4.22 days with a
mean of 3.79 ± 0.20 days. The longevity of adult female ranged from 25.87-33.91 days
with a mean of 29.58 ± 1.28 days.
The egg is transparent, kidney shaped and measures from 3-4 µm in length and 6-
9 µm in width. The first instar is whitish and measures from 13-15 µm in length and 3.00
µm in width. The second larval instar is yellowish and measures from 20-24 µm in length
and 5-7 µm in width. The pupa I is yellowish, with wing pads half of the body and
measures from 29-33 µm in length and 7-8 µm in width. The pupa II is yellowish wing
longer wing pads, antennae turned back over the prothorax and measures from 31-34 µm
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
28
in length and 8 µm in width. The body of adult thrips is yellowish, red eyes, black head,
white prothorax, black mesothorax and metathorax and wings and abdomen with black
and white bands. The body length is 34-42 µm and 8-10 µm in width.
The predatory stages use its forelegs and mouthparts to catch and hold the prey.
They pierce the integument and suck the body contents of the prey by means of their
mandibulary and maxillary stylets aided by slight rotation of its head.
The female thrips oviposit its egg into the leaf tissue through the saw-like
ovipositor. It can lay as many as 15 to 31 eggs.
The larva I consumed an average of 10.2 eggs, 11.6 larvae, 5.8 nymphs and 2.6
adults. The larva II consumed an average of 32.2 eggs, 30.6 larvae, 20.2 nymphs and 8.8
adults. The adult banded wing thrips consumed an average of 342.6 eggs, 435 larvae,
255.6 nymphs and 126 adult.
The host preference of larva I were both egg and larva, the larva II prefers larva
while the adult prefers the adult two-spotted spider mites.
Conclusion
It is therefore concluded that the life cycle of black-banded wing thrips
(Aelothrips sp.) under laboratory condition ranges from 49.42-68.48 days. The predatory
stages catch and hold the prey with the aid of its forelegs and mouthparts as they pierce
the integument and suck the body contents of the prey by means of their mandibulary and
maxillary. The eggs are inserted into the leaf tissue through their saw-like ovipositor. The
adult female Aelothrips sp. can lay as many as 15 to 31 eggs. The thrips is effective
predator of two-spotted spider mites. The host preference of larva I are both egg and
larva, the larva II prefers larva while the adult prefers the adult two-spotted spider mites.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
29
Recommendation
It is recommended to study the field efficiency of black-banded wing thrips
against two-spotted spider mites.
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
30
LITERATURE CITED
BARBARA, C. 2009. Notes on the presence of Aeolothrips intermedius in northwestern
(1): 107-112, 2009. ISSN 1721-886. Retrieved August 6, 2010 from
http://www.bulletinofinsectology.org/pdfarticles/vol62-2009-107-112conti.pdf
DAS-ILEN, G. S. 2010. Presencce of banded wing thrips in BSU, La Trinidad,
Benguet
(personal
interview).
HANCOOK, J. F.1999. Strawberries. CABI Publishing. New York, USA. Pp. 153-154.
LAYAO, J. A. 1998. Test on the voracity of predatory thrips (Scolothrips sexmaculatus
Pergande) on red spider mites. BS Thesis. BSU, La Trinidad,
Benguet. Pp.
14,
16.
MCGINLEY, M. 2009. Ecology, Animal Behavior (behavioral Ecology) and
Evolutionary Biology. December 28, 2009. Retrieved December 28, 2009 from
htt://www.eoearth.org/article/predation
FLINT, P. W. and METCALF, L. C. 1962. Destructive and Useful Insects “Their Habits
and Habitat and Control (4th ed.) New Delhi, India. Tata-McgraHill Publishing
Campany LTD. Pp. 211-212.
PECDASEN, F. B. 1996. Biology of spider mites (Tetranychus urticae Koch) feeding
on chrysanthemum. BS thesis. BSU. La Trinidad, Benguet. P. 27.
TANYAG, R C. 1996. Biology and abundance of red spider mites (Tetranychus
Kansawai
Kishida) on strawberry and its natural enemies and alternate host.
MS Thesis. Benguet State University, La Trinidad, Benguet. Pp. 23-27, 41.
UNIVERSITY OF CALIFORNIA. 2008. Distinguishing Feature of Banded Wing Thrips
Retrieved August 5, 2010, from htt://keys.
Lucidcentral.org/keysv3thrips of california/data/key/thysanoptera/Media/Htm/br
owse_species/Aeolothrips_fasciatus.htm
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
31
APPENDICES
Appendix Table 1. Duration (days) of the different growth stages of a female black-
banded wing thrips
STAGES OF
REPLICATION
PREDATOR
I II III
IV
TOTAL
V
MEAN
Egg
11.74 16.03 15.31 13.81 15.65 72.54 14.51
Larva
I
7.02 5.96 4.80 7.89 5.91 31.58 6.32
Larva
II
2.86 3.79 3.86 4.09 4.2 18.8 3.76
Pupa
I
1.05 2.23 1.66 1.38 2.22 8.54 1.71
Pupa
II
3.96 3.10 4.13 4.22 3.56 18.87 3.79
Adult
33.91 29.60 29.57 28.95 25.87 147.9 29.58
TOTAL
60.54 60.71 59.33 60.34
57.4 298.32 59.646
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
32
Appendix Table 2. Length (µm) of the different growth stages of a female black-banded
wing thrips
STAGE OF
REPLICATION
PREDATOR I II III IV V VI VII
TOTAL
VIII
MEAN
Egg
8 8 8 9 8 7 6 8 62 7.75
Larva
I
15 14 13 15 15 13 15 14 114 14.25
Larva
II 20 20 22 22 23 24 21 22 174 21.75
Pupa
I
31 32 32 29 33 30 30 33 250 31.25
Pupa
II
32 32 33 31 34 34 34 34 264 33
Adult
41 42 41 34 41 41 40 39 319 39.88
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
33
Appendix Table 3. Width (µm) of the different growth stages of a female black-banded
wing thrips
STAGE OF
REPLICATION
PREDATOR I II III IV V VI VII
TOTAL
VIII
MEAN
Egg
4 3 3 4 4 4 4 3 29 3.63
Larva
I 3 3 3 3 3 3 3 3 24 3
Larva
II 5 5 5 5 5 5 5 6 41 5.13
Pupa
I
8 8 7 8 8 8 7 8 62 7.75
Pupa
II 8 8 8 8 8 8 8 8 64 8
Adult 8
9
9
10
9
9
8
8
70
8.75
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
34
Appendix Table 4. Total consumption rate of the different growth stages of black-banded
wing predatory thrips on two-spotted spider mite egg
PREDATORY
REPLICATION
TOTAL MEAN
STAGE
I
II
III
IV
V
Larva I
10
8
13
9
11
51
10.2b
Larva
II 22 32 56 44 32 186
37.2b
Adult
371 354 421 220 347 1713
342.6a
ANOVA TABLE
SOURCE OF
TABULATED F
VARIANCE
DF
SS
MS
F VALUE
0.05 0.01
Treatment 2
340813.20 170406.60
89.56**
3.88
6.93
Error 12
22832.80
1902.73
TOTAL 14
363646.00
** - Highly significant CV = 33.55 %
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
35
Appendix Table 5. Total consumption rate of the different growth stages of black-banded
wing predatory thrips on two-spotted spider mite larva
PREDATORY
REPLICATION
STAGE
I
II
III
IV
V
TOTAL MEAN
Larva
I 12 13 7 13 13
58 11.6b
Larva
II 34 29 39 28 23 153
30.6b
Adult
246 442 379 511 600 2178
435.6a
ANOVA TABLE
SOURCE OF
TABULATED F
VARIANCE
DF
SS
MS
FVALUE
0.05 0.01
Treatment 2
573603.3333 286801.6667
47.75**
3.88
6.93
Error 12
72081.6000
6006.8000
TOTAL 14
645684.9333
** - Highly significant CV = 48.66 %
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
36
Appendix Table 6. Total consumption rate of the different growth stages of black-banded
wing predatory thrips on two-spotted spider mite nymph
PREDATORY
REPLICATION
STAGE
I
II
III
IV
V
TOTAL MEAN
Larva
I 7 6 5 6 5
29
5.8c
Larva
II 22 17 20 22 20 101
20.2b
Adult
245 267 256 258 252 1278
255.6a
ANOVA TABLE
SOURCE OF
TABULATED F
VARIANCE
DF
SS
MS
F VALUE
0.05 0.01
Treatment 2
196700.9333 98350.4667 4203.01**
3.88
6.93
Error 12
280.8000
23.4000
Total 14
196981.7333
** - Highly significant CV = 5.15 %
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
37
Appendix Table 7. Total consumption rate of the different growth stages of black-banded
wing predatory thrips on two-spotted spider mite adult
PREDATORY
REPLICATION
TOTAL MEAN
STAGE
I
II
III
IV
V
Larva
I 3 3 2 3 2
13
2.6b
Larva
II 6 13 9 8 8
44
8.8b
Adult 79
181
92
120
158
630
126a
ANOVA TABLE
SOURCE OF
TABULATED F
VARIANCE
DF
SS
MS
F VALUE
0.05 0.01
Treatment 2
48336.60
24168.20
38.78**
3.88
6.93
Error 12
7478.00
623.1667
Total 14
55814.40
** - Highly significant CV = 54.51 %
Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted
Spider Mites (Tetranychus urticae Koch) / JEROME I. APIDOS. 2011
Document Outline
- Life Cycle and Predation Rate of Black-Banded Wing Thrips (Aeolothrips sp.) on Two-Spotted Spider Mites (Tetranychusurticae Koch)
- BIBLIOGRAPHY
- ABSTRACT
- TABLE OF CONTENTS
- INTRODUCTION
- REVIEW OF LITERATURE
- METHODOLOGY
- RESULTS AND DISCUSSION
- SUMMARY, CONCLUSION AND RECOMMENDATION
- LITERATURE CITED
- APPENDICES