BIBLIOGRAPHY DELLIAS, ERIC C. APRIL ...
BIBLIOGRAPHY
DELLIAS, ERIC C. APRIL 2007. Documentation on Bumblebees (Bombus terristris
Linnaeus) as Pollinator of Tomato under Greenhouse Condition in Israel. Benguet State
University, La Trinidad, Benguet.
Adviser: Lita M. Colting, PhD
ABSTRACT
The study was conducted at Kibbutz Sde Elyahu, Beit Shean Valley, Israel from January
to July 2006 to observe how bumblebees are used as pollinator of tomatoes under greenhouses.
Fifteen (15) bumblebee colonies were situated to pollinate tomatoes inside 1.5 hectares.
The bumblebee colonies were maintained inside the greenhouse from the time the tomato
flowers bloom up to the last bloom.
The increased in yield was estimated to be 25% as a result of bumble pollination.
TABLE OF CONTENTS
Page
Bibliography …………………………………………………………………
i
Abstract
…………………………………………………………………… i
Table of Contents
…………………………………………………………… ii
INTRODUCTION
Rationale ……………………………………………………………….. 1
Statement of the Problem ……………………………………………. 2
Objectives of the Study ……………………………………………... 3
Importance of the Study …………………………………………….. 3
Scope and Limitation of the Study ……………………………………. 3
REVIEW OF LITERATURE
The bumblebees
…………………………........................................ 4
Bumblebee Compared to Honeybees ………………………………… 5
METHODOLOGY
Locale and Time of the Study …………………………………………… 7
Respondents of the Study
…………………………………………… 9
Data Collection ……………………………………………………… 9
Data Gathered …………………………………………………….... 9
Data Analysis ………………………………………………………. 9
RESULTS AND DISCUSSION
Tomato Production in Israel ………………………………………. 10
Bumblebee Industry …………………………………………………. 10
Rearing of Bumblebees
…………………………………………… 11
The Bumblebee hive ………………………………………………. 12
Arrangement of the Bumblebee hive ………………………………. 14
Transport of Bumblebee hive …………………………………….. 16
Bumblebee Colonies inside the Greenhouse ……………………… 16
Behavioral Characteristics of Bumblebee …………………………….
17
Efficiency of Bumblebee Pollinator …………………………………..
19
SUMMARY AND CONCLUSION
Summary ……………………………………………………………....
21
Conclusion ……………………………………………………………... 21
Recommendation .................................................................................. 22
LITERATURE CITED ………………………………………………………... 23
1
INTRODUCTION
Rationale
Israel is one of the countries that developed appropriate technologies in
agriculture, such that despite its barren land it is one of the top ranking exporters of fresh
produce to Europe and western countries. Israeli agriculturists, scientists and researchers
continue to explore to geared on improving the quality and quantity of the products, to
satisfy the consumers, and to meet the needs of the farmers. One of the technologies that
they promote is the use of natural pollinators to increase and improve the quality and the
quantity of products. They also practice environment-friendly pest management allowing
pollinators to thrive in greenhouses. They grow agricultural crops in greenhouses and
employ drip fertigation to optimize the use of water which is a very limited resource in
the country.
The bumblebee is an ideal natural pollinator for protected crops such as
greenhouse tomato, bell pepper, strawberry, and an important backup for outdoor crops
during marginal seasons. Unlike honeybees – also important pollinators of crops,
bumblebee adapts well to confined greenhouse conditions as stated by Aviel (2006). It
has been shown that the use of bumblebees in tomato greenhouse has increased the yield
of export – quality tomatoes by 25% compared to manual pollination.
Before, Israel farmers usually pollinate greenhouse crops with artificial method
and manual pollination. Farmers tried to use honeybees in greenhouse but it was not
successful for honeybees prefer open field condition, hence alternative pollinator with the
use of bumblebees has been looked into (Aviel, 2006).
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
2
The tomato (Lycopersicon esculentum, Mill) flower is self-fertile or self-
pollinating, containing both stamens and pistil. The flower has six yellow petals and six
stamens that unite at the tip of the anthers to form a cone surrounding the pistil. In order
for the flower to be pollinated, the flower needs to be vibrated to let the pollen fall into
the cone of stamens and land on the stigma at the tip of the style. When the style is
shorter than the surrounding cone, normal contact can occur between the pollen and the
stigma, however, when the style protrudes out of the cone it is difficult for the pollen to
meet the stigma.
Statement of the Problem
Unlike in open areas, condition inside the greenhouse do not favor self
pollination of tomato flower for the relative humidity is high and there is low air
movement so the flowers are not shaken enough to allow self pollination. The artificial
shaking of the flower can be optimally achieved by the introduction of bumblebees.
Bumblebee is capable of vibrating the tomato flower using its unique buzz pollination
mechanism which is claimed to be far superior to any manual or artificial pollinators such
as electric bee, pulse air or hormones (Aviel, 2006).
Research was perform on the natural pollinator (the bumblebees) and was
documented. There is a need, therefore, to answer the following questions:
1. What are the practices involved in planting tomatoes in Israel?
2. What are the processes in mass producing bumblebees?
3. How and when are the bumblebee colonies set inside the greenhouse?
4. How the bumblebees pollinate tomatoes?
5. What makes bumblebees an efficient pollinator of tomatoes?
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
3
Objectives of the Study
1. To identify the practices involved in planting tomatoes?
2. To discuss how bumblebees are reared.
3. To describe the characteristics of bumblebee in pollinating tomatoes.
4. To discuss how the bumblebee colonies are set inside the greenhouse.
5. To show the bumblebee as pollinators are far better than other means.
Importance of the Study
The study will be a point of reference for further research and will serve as a
guide when adaptation of the technology will be considered.
Also, it will give information on bumblebees adapted as a natural pollinator that
boost the greenhouse products of Israel that leads as one of the exporter of fresh produce
in the Middle East.
Scope and Limitation of the Study
Data gathering for the study was conducted on January to July 2006. This was
conducted at Beit She’an Valley, Israel.
The study was limited to the ocular observations of the researcher and personal
interview with Shaul Aviel a field service advisor who gave lectures, demonstrations, and
data regards to the study.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
4
REVIEW OF LITERATURE
The Bumblebees
Bumblebees are similar to their close relatives, the honey bees, and that their
colonies are headed by a queen, which is the main egg-layer, and many workers, which
are the daughters of the queen, and the drones (males) which are being produced during
the mating season. However, the colonies of bumblebees, unlike those of honey bees,
only survive during the warm season; new queens hibernate alone to begin another
colony the following spring. In addition, there is usually lesser number in a bumblebee
colony than in a honeybee colony and bumblebees do not use a dance to communicate the
location of food to other members of the colony, as honey bees do. They do not also store
large amount of honey as honeybees do. The biology of bumblebees has been well
studied, and is shown in Figure 1 (Aviel, 2006).
Figure 1. An illustration of the life cycle of bumblebee
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
5
Bumblebees are important pollinators of many plants like tomato, avocado,
eggplant, cherry, courgette and bell pepper. Both queens and workers collect pollen and
transport it back to the colony in the pollen baskets on their hind legs. Workers are small
if born early in the year, and large if born later. Also, some species of bumblebees are
larger than others. Differences in body size, and especially in tongue length, are
important in determining which flower species a bumblebee will visit for nectar and may
determine which flowers it can pollinate (Sugden, 1997).
Sugden (1997) further mentioned that bumblebee is also recognized as vital to the
production of certain seed crops. Bee scientists have developed a means to cause queens
to skip their winter hibernation and produce colonies year-round. Enabling bumblebees to
be reared in hive boxes, available for use in pollinating crops anytime of the year and in
various places.
Also, bumblebees are increasingly cultured for agricultural use as pollinators
because they can pollinate plant species that other pollinators cannot by using a technique
known as buzz pollination. For example, bumblebee colonies are often placed in tomato
production inside the greenhouse because the frequency of buzzing that a bumblebee
exhibits effectively pollinates tomatoes (McDonald et al., 2006).
Bumblebee Compared to Honeybees
Compared to the honeybees, the bumblebee is capable of vibrating the flower
using the unique buzz pollination mechanism for the tomato flower needs vibration for
proper pollination and fruit set, under greenhouse conditions. Unlike the honeybee, the
bumblebee is less affected by adverse weather conditions. Temperatures below 15
degrees centigrade, rain or cloudiness above 70 degrees centigrade will keep the
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
6
honeybees in their hives but not the bumblebees which will continue functioning without
interference. This characteristic makes the bumblebees excellent pollinators of winter
crops. Unlike the honeybee, the bumblebee is better adapted to perform under confined
greenhouse conditions. The bumblebee is less inclined to look for alternative sources of
pollen and nectar outside the greenhouse. Therefore the bumblebees will stay inside the
greenhouse even if it is opened for ventilation purposes. Also, bumblebees are vulnerable
to pesticides. It is desirable to use non-chemical alternative as possible to control pests in
crops. Since bumblebees were introduced into greenhouse tomatoes in Israel, there has
been a 50% reduction in the overall chemical input in crops. Their application in the
greenhouse requires a friendlier pest control regime (Aviel, 2006).
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
7
METHODOLOGY
Locale and Time of the Study
The study was conducted at a farm of Beit She’an Valley (Figure 2), Israel from
January to July 2006. It is located in a valley wider that La Trinidad valley in Benguet
where the main campus of Benguet State University is established. The temperature was
32 ْ◌ C during the conduct of the study.
The place was chosen as the study area for it is where the kibbutz that started the
mass rearing of bumblebees for local and for export market was located. Map of the study
area was shown in Figure 3.
Figure 2. Greenhouses in Beit Shean Valley
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
8
Figure 3. Map of Israel showing Beit Shean Valley
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
9
Respondents of the Study
The study was dependent on the ocular observations of the researcher and an
interview with Shaul Aviel. (Field Service Advisor) who gave the lectures, information
and demonstrations on bumblebees this shown in Figure 4.
Figure 4. An interview with Shaul Aviel
Data Collection
A personal interview with Shaul Aviel (Field Service Advisor), visits to
greenhouses, ocular observations and photo taking were done.
Data Gathered
The data gathered were the different practices involved in planting tomatoes; the
rearing of bumblebees; characteristics of bumblebee as pollinator of tomatoes; bumblebee
colonies set inside the greenhouse and the efficiency of bumblebees as pollinators.
Data Analysis
The data gathered were consolidated and presented in narrative form with photo
documented.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
10
RESULTS AND DISCUSSION
Tomato Production in Israel
Tomato productions in Israel are done under polyethylene greenhouse or
glasshouses because of adverse weather conditions such as rainy-winter, excessive heat
during summer and frequent changes of air temperature. The dimension of the
greenhouse was 125 x 120 meters. The tomatos were planted on soil and/or artificial
medium like coconut husk with plastic covering. The distance between plants is 50 cm
and the distance between plots is 100 cm. The tomatoes while young were provided with
supporting trails with the use of nylon strings, but as they become taller the lower stems
were laid in the ground. This was done to lower the height of the tomato to easily reach
the fruits during the harvest. The tomatoes can reach a maximum height of 10 m.
In terms of irrigation and fertilizer application, the water and fertilizers were
mixed in big tanks that were connected to pressurized water pumps and to allow equal
distribution of water and fertilizer. A main pipe was connected to the water pump, where
secondary pipes or the pipes with drippers were connected. The drippers were laid near or
parallel the tomato plants where the liquid will form circular-form until each will meet.
The process is called fertigation. Before fertigation, the nutrition needed by the plant is
first analyzed.
Bumblebee Industry
Bumblebee has become a commodity in Israel because of the efficiency as
pollinator of thousands of hectares of greenhouses tomatoes. The economy Bio-Bee
located at Sde, Eliyahu, Beit Shean Valley, Israel has been mass producing bumblebee as
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
11
pollinators since 1990. In Israel, Bio-Bee Company supply pollination services to more
than 500 hectares and over 1000 clients. Also, bumblebee hives are exported to Europe,
Japan, Africa, and South America.
Tomato growers in Beit Shean Valley preferred to use bumblebee as natural
pollinator for their crops. Results shown in Table 1.
Table 1. The number of farmers using bumblebees as pollinator of tomato crops in each
Kibbutz of Beit Shean Valley
KIBBUZT TOTAL NO. OF FARMERS
NO. OF BUMBLEBEE USERS
Shluckot
6
6
Lofan
5
5
Kfar Ruppin
8
8
Yardenit
5
5
Sde Eliyahu
6
6
TOTAL 30
Rearing of Bumblebees
The bumblebees (Bombus terristris Linnaeus) or the large earth bumblebees are
reared in dark rooms or naturally, they dig and build their colony under the ground.
Kibbutz Sde Elyahu the pioneer of mass production has especial rooms in rearing
bumblebees. The rooms should be dark and were highly monitored to avoid the entry of
diseases that can cause damage to the starting colonies. Red lights are being used for
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
12
monitoring and checking the colonies, for bumblebees can not visualize red lights.
Unfortunately, the rearing house was not visited as it is restricted to visitors.
The Bumblebee Hive
Figure 5 shows the white and clean plastic box where the bumblebees from the
rearing house are placed for field distribution. The box has been especially designed to
provide maximum ventilation with the provision of numerous slits at the bottom of the
box, sidewalls and lids to allow airflow that helps the bumblebees quickly and efficient
remove dirt to keep the hive clean. Clean hives lengthen lifespan of the bees.
The bumblebees are provided with artificial food with the provision of a bag of
sugar-water with drinking apparatus in a separate unit within a cardboard covering
beneath the bee colony (Figure 6). The bumblebees obtain their food through a wick,
which transports the liquid from the bag into the brood compartment. Between the
plastic inner housing colony box and the food unit there is a thick layer of styrofoam
(about 2 cm) with a cotton wool covering the brood from above to provide maximum
insulation for the bumblebees.
Figure 7 shows the addition of dry pollen to the hive as a natural dietary
supplement. These are put at the center of the square part of the plastic inner lid with
slightly raised borders where the pollen eventually falls and become accessible to the
bees.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
13
Figure 5. The white box where the bumblebee colony are placed for field
use after they have been reared in dark room
Food
container
wick
Figure 6. Bag of water-sugar (food) and the drinking apparatus
pollen
Figure 7. Dry pollen is added to the hive as a dietary supplement
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
14
Arrangement of the Bumblebee hive
For final transport to the fields, the plastic hives are put inside a cartoon box
(Figures 8 and 9), provided with two openings that will serve as passage for the bees
when these are settled in the greenhouses. These openings are provided with shutter
(Figures 10 and 11).
Food
Wick
Figure 8. The top view with the water-sugar, Figure 9. The top view, food covered with
food court and food wick
styrofoam
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
15
Figure 10. The bee colony in polyethylene put Figure 11. The top and side view of the
through the cartoon box
bumblebee hive
Figures 12 to 14 show the full lowering of the plastic shutter to block totally both
the flight-holes during transport. If the colony is transferred to another plantation, one of
the holes will be kept open. This flight-hole allows the bees to enter and will not able to
exit. If the colony is used for pollination the plastic shutter is opened to the maximum to
expose the two flight-holes. These allow the bees to enter and exit in front of the hive.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
16
Figure 12. The flight-holes are closed
Figure 13. One flight-hole is opened
Figure 14. The two flight-holes are fully opened
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
17
Transport of Bumblebee hive
Figure 15 shows sets of bumblebee colonies inside the packing house ready for
transport to various farms within Israel or for export. Bumblebee colonies are being
transported by close van truck with controlled temperature 28 ْ◌ C. During the transport
all the colony is closed and sealed.
Figure 15. Bumblebee colonies in cartoon hive box ready for market
Bumblebee Colonies Inside the Greenhouse
Fifteen (15) colonies of bumblebees are put inside a 1.5 hectares greenhouse
when the tomato flowers are about to bloom until the flowering stage will end. The
colonies are set up at least two (2) ft. from the ground with the provision of stands either
made of wood or metal materials (Figures 16 to 17). The colonies are set in the corner of
the greenhouse near the entrance and about three (3) ft. apart. The setting up of colonies
is done 9 o’clock in the morning. After the colonies are set up, the plastic shutter is lifted
to open the flight-holes so that the bees can enter in and exit from the hive respectively.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
18
Figure 16. A bumblebee colony set on top of a table
Figure 17. The researcher showing a colony set on metal stand
Behavioral Characteristics of Bumblebee
Bumblebees are efficient pollinator of tomatoes for they are able to open the
tomato flower in order to be pollinated. They have a heavy body that upon clinging on
the flower, the latter bends allowing the flower-cone to open and also the falling of the
pollens. Apart from this the bumblebee vibrates its wings while bending its body causing
the shaking of the tomato flower. This activity enhances the falling of the pollen grains to
the stigma resulting to pollination. This kind of pollination system is called buzz
pollination.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
19
The following photos (Figures 18 to 20) show a tomato flower before and after
bumblebee visitation. A flower with scars caused by bumblebees eventually fruit set,
while flowers that has no scars, pictures that there was no visitation happened.
Figure 18. Unpollinated tomato flower
Figure 19. Bumblebee visiting a tomato flower
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
20
scars
Figure 20. A tomato flower with scars indicating successful pollination
Efficiency of Bumblebee Pollinator
Figures 21 to 22 show two tomato plantations grown in various media that were
pollinated by bumblebees. The crop in-charge claims that the use of bumblebees in
tomato production under greenhouses has increased the yield of export quality tomatoes
by 25% compared to manual pollination.
Figure 21. Tomatoes pollinated by bumblebees grown in soil medium
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
21
Figure 22. Tomatoes pollinated by bumblebees grown in artificial medium
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
22
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The study was conducted at Kibbutz Sde Elyahu, Beit Shean Valley, Israel from
January 2006 to July 2006 to observed tomato plantations inside the greenhouse, to
observed the behavioral characteristics of bumblebees that makes it efficient as pollinator
of tomatoes and to observed how colony is prepared and set in tomato plantations.
The tomatoes are planted in soil or artificial medium. The distance between plants
is 50 cm. and between plots is 1 m. The tomato is provided with supporting trails but the
lower stems are laid in the ground as they mature. Water and fertilizers are applied
through fertigation.
Bumblebees are attracted to the yellow flowers. They visit fully bloomed flowers
and as they cling to the petals that cover the pistil and it bends allowing the flower-cone
to open. The wings of the bumblebees continue vibrate causing the tomato flower to
shake and the falling of pollen grains into the pistil.
The bumblebee colony covered of white plastic box with ventilation, encased of
cartoon boxes provided with food. The colonies were transported in closed van truck. The
colonies were set near the entrance of the greenhouse with stand.
Conclusion
Bumblebee colonies are introduced as pollinators in tomatoes under greenhouse
condition in Israel. The bumblebees increased yield and improved fruit quality.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
23
Recommendation
Based on the results and observations the researcher recommend that the use of
natural pollinators should be adopted in the country especially in promoting organic
farming and upholding the use of biological control.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
24
LITERATURE CITED
AVIEL, S. 2006. Biology of Earth Bumblebee: On USB. Available: Bio-Bee Beit Shean
Valley, Israel. [July 10, 2006].
MCDONALD, M. and G. NISBET. 2006. Highland Bumblebees: Distribution, Ecology
and Conservation. Retrieved February 10, 2007 from http://www.hbrg.org.uk
MCMASTERS JOHN H. 1989. The flight of the bumblebees and related myths
Entomological Engineering. Retrieved February 10, 2007 from
http://www.hbrg.org.uk
SUGDEN, E. A. 1997. Bumble Bee. Retrieved February 10, 2007 from
http://encarta.msm.com
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
DELLIAS, ERIC C. APRIL 2007. Documentation on Bumblebees (Bombus terristris
Linnaeus) as Pollinator of Tomato under Greenhouse Condition in Israel. Benguet State
University, La Trinidad, Benguet.
Adviser: Lita M. Colting, PhD
ABSTRACT
The study was conducted at Kibbutz Sde Elyahu, Beit Shean Valley, Israel from January
to July 2006 to observe how bumblebees are used as pollinator of tomatoes under greenhouses.
Fifteen (15) bumblebee colonies were situated to pollinate tomatoes inside 1.5 hectares.
The bumblebee colonies were maintained inside the greenhouse from the time the tomato
flowers bloom up to the last bloom.
The increased in yield was estimated to be 25% as a result of bumble pollination.
TABLE OF CONTENTS
Page
Bibliography …………………………………………………………………
i
Abstract
…………………………………………………………………… i
Table of Contents
…………………………………………………………… ii
INTRODUCTION
Rationale ……………………………………………………………….. 1
Statement of the Problem ……………………………………………. 2
Objectives of the Study ……………………………………………... 3
Importance of the Study …………………………………………….. 3
Scope and Limitation of the Study ……………………………………. 3
REVIEW OF LITERATURE
The bumblebees
…………………………........................................ 4
Bumblebee Compared to Honeybees ………………………………… 5
METHODOLOGY
Locale and Time of the Study …………………………………………… 7
Respondents of the Study
…………………………………………… 9
Data Collection ……………………………………………………… 9
Data Gathered …………………………………………………….... 9
Data Analysis ………………………………………………………. 9
RESULTS AND DISCUSSION
Tomato Production in Israel ………………………………………. 10
Bumblebee Industry …………………………………………………. 10
Rearing of Bumblebees
…………………………………………… 11
The Bumblebee hive ………………………………………………. 12
Arrangement of the Bumblebee hive ………………………………. 14
Transport of Bumblebee hive …………………………………….. 16
Bumblebee Colonies inside the Greenhouse ……………………… 16
Behavioral Characteristics of Bumblebee …………………………….
17
Efficiency of Bumblebee Pollinator …………………………………..
19
SUMMARY AND CONCLUSION
Summary ……………………………………………………………....
21
Conclusion ……………………………………………………………... 21
Recommendation .................................................................................. 22
LITERATURE CITED ………………………………………………………... 23
1
INTRODUCTION
Rationale
Israel is one of the countries that developed appropriate technologies in
agriculture, such that despite its barren land it is one of the top ranking exporters of fresh
produce to Europe and western countries. Israeli agriculturists, scientists and researchers
continue to explore to geared on improving the quality and quantity of the products, to
satisfy the consumers, and to meet the needs of the farmers. One of the technologies that
they promote is the use of natural pollinators to increase and improve the quality and the
quantity of products. They also practice environment-friendly pest management allowing
pollinators to thrive in greenhouses. They grow agricultural crops in greenhouses and
employ drip fertigation to optimize the use of water which is a very limited resource in
the country.
The bumblebee is an ideal natural pollinator for protected crops such as
greenhouse tomato, bell pepper, strawberry, and an important backup for outdoor crops
during marginal seasons. Unlike honeybees – also important pollinators of crops,
bumblebee adapts well to confined greenhouse conditions as stated by Aviel (2006). It
has been shown that the use of bumblebees in tomato greenhouse has increased the yield
of export – quality tomatoes by 25% compared to manual pollination.
Before, Israel farmers usually pollinate greenhouse crops with artificial method
and manual pollination. Farmers tried to use honeybees in greenhouse but it was not
successful for honeybees prefer open field condition, hence alternative pollinator with the
use of bumblebees has been looked into (Aviel, 2006).
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
2
The tomato (Lycopersicon esculentum, Mill) flower is self-fertile or self-
pollinating, containing both stamens and pistil. The flower has six yellow petals and six
stamens that unite at the tip of the anthers to form a cone surrounding the pistil. In order
for the flower to be pollinated, the flower needs to be vibrated to let the pollen fall into
the cone of stamens and land on the stigma at the tip of the style. When the style is
shorter than the surrounding cone, normal contact can occur between the pollen and the
stigma, however, when the style protrudes out of the cone it is difficult for the pollen to
meet the stigma.
Statement of the Problem
Unlike in open areas, condition inside the greenhouse do not favor self
pollination of tomato flower for the relative humidity is high and there is low air
movement so the flowers are not shaken enough to allow self pollination. The artificial
shaking of the flower can be optimally achieved by the introduction of bumblebees.
Bumblebee is capable of vibrating the tomato flower using its unique buzz pollination
mechanism which is claimed to be far superior to any manual or artificial pollinators such
as electric bee, pulse air or hormones (Aviel, 2006).
Research was perform on the natural pollinator (the bumblebees) and was
documented. There is a need, therefore, to answer the following questions:
1. What are the practices involved in planting tomatoes in Israel?
2. What are the processes in mass producing bumblebees?
3. How and when are the bumblebee colonies set inside the greenhouse?
4. How the bumblebees pollinate tomatoes?
5. What makes bumblebees an efficient pollinator of tomatoes?
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Objectives of the Study
1. To identify the practices involved in planting tomatoes?
2. To discuss how bumblebees are reared.
3. To describe the characteristics of bumblebee in pollinating tomatoes.
4. To discuss how the bumblebee colonies are set inside the greenhouse.
5. To show the bumblebee as pollinators are far better than other means.
Importance of the Study
The study will be a point of reference for further research and will serve as a
guide when adaptation of the technology will be considered.
Also, it will give information on bumblebees adapted as a natural pollinator that
boost the greenhouse products of Israel that leads as one of the exporter of fresh produce
in the Middle East.
Scope and Limitation of the Study
Data gathering for the study was conducted on January to July 2006. This was
conducted at Beit She’an Valley, Israel.
The study was limited to the ocular observations of the researcher and personal
interview with Shaul Aviel a field service advisor who gave lectures, demonstrations, and
data regards to the study.
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Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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REVIEW OF LITERATURE
The Bumblebees
Bumblebees are similar to their close relatives, the honey bees, and that their
colonies are headed by a queen, which is the main egg-layer, and many workers, which
are the daughters of the queen, and the drones (males) which are being produced during
the mating season. However, the colonies of bumblebees, unlike those of honey bees,
only survive during the warm season; new queens hibernate alone to begin another
colony the following spring. In addition, there is usually lesser number in a bumblebee
colony than in a honeybee colony and bumblebees do not use a dance to communicate the
location of food to other members of the colony, as honey bees do. They do not also store
large amount of honey as honeybees do. The biology of bumblebees has been well
studied, and is shown in Figure 1 (Aviel, 2006).
Figure 1. An illustration of the life cycle of bumblebee
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Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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Bumblebees are important pollinators of many plants like tomato, avocado,
eggplant, cherry, courgette and bell pepper. Both queens and workers collect pollen and
transport it back to the colony in the pollen baskets on their hind legs. Workers are small
if born early in the year, and large if born later. Also, some species of bumblebees are
larger than others. Differences in body size, and especially in tongue length, are
important in determining which flower species a bumblebee will visit for nectar and may
determine which flowers it can pollinate (Sugden, 1997).
Sugden (1997) further mentioned that bumblebee is also recognized as vital to the
production of certain seed crops. Bee scientists have developed a means to cause queens
to skip their winter hibernation and produce colonies year-round. Enabling bumblebees to
be reared in hive boxes, available for use in pollinating crops anytime of the year and in
various places.
Also, bumblebees are increasingly cultured for agricultural use as pollinators
because they can pollinate plant species that other pollinators cannot by using a technique
known as buzz pollination. For example, bumblebee colonies are often placed in tomato
production inside the greenhouse because the frequency of buzzing that a bumblebee
exhibits effectively pollinates tomatoes (McDonald et al., 2006).
Bumblebee Compared to Honeybees
Compared to the honeybees, the bumblebee is capable of vibrating the flower
using the unique buzz pollination mechanism for the tomato flower needs vibration for
proper pollination and fruit set, under greenhouse conditions. Unlike the honeybee, the
bumblebee is less affected by adverse weather conditions. Temperatures below 15
degrees centigrade, rain or cloudiness above 70 degrees centigrade will keep the
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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honeybees in their hives but not the bumblebees which will continue functioning without
interference. This characteristic makes the bumblebees excellent pollinators of winter
crops. Unlike the honeybee, the bumblebee is better adapted to perform under confined
greenhouse conditions. The bumblebee is less inclined to look for alternative sources of
pollen and nectar outside the greenhouse. Therefore the bumblebees will stay inside the
greenhouse even if it is opened for ventilation purposes. Also, bumblebees are vulnerable
to pesticides. It is desirable to use non-chemical alternative as possible to control pests in
crops. Since bumblebees were introduced into greenhouse tomatoes in Israel, there has
been a 50% reduction in the overall chemical input in crops. Their application in the
greenhouse requires a friendlier pest control regime (Aviel, 2006).
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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METHODOLOGY
Locale and Time of the Study
The study was conducted at a farm of Beit She’an Valley (Figure 2), Israel from
January to July 2006. It is located in a valley wider that La Trinidad valley in Benguet
where the main campus of Benguet State University is established. The temperature was
32 ْ◌ C during the conduct of the study.
The place was chosen as the study area for it is where the kibbutz that started the
mass rearing of bumblebees for local and for export market was located. Map of the study
area was shown in Figure 3.
Figure 2. Greenhouses in Beit Shean Valley
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Figure 3. Map of Israel showing Beit Shean Valley
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Respondents of the Study
The study was dependent on the ocular observations of the researcher and an
interview with Shaul Aviel. (Field Service Advisor) who gave the lectures, information
and demonstrations on bumblebees this shown in Figure 4.
Figure 4. An interview with Shaul Aviel
Data Collection
A personal interview with Shaul Aviel (Field Service Advisor), visits to
greenhouses, ocular observations and photo taking were done.
Data Gathered
The data gathered were the different practices involved in planting tomatoes; the
rearing of bumblebees; characteristics of bumblebee as pollinator of tomatoes; bumblebee
colonies set inside the greenhouse and the efficiency of bumblebees as pollinators.
Data Analysis
The data gathered were consolidated and presented in narrative form with photo
documented.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
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RESULTS AND DISCUSSION
Tomato Production in Israel
Tomato productions in Israel are done under polyethylene greenhouse or
glasshouses because of adverse weather conditions such as rainy-winter, excessive heat
during summer and frequent changes of air temperature. The dimension of the
greenhouse was 125 x 120 meters. The tomatos were planted on soil and/or artificial
medium like coconut husk with plastic covering. The distance between plants is 50 cm
and the distance between plots is 100 cm. The tomatoes while young were provided with
supporting trails with the use of nylon strings, but as they become taller the lower stems
were laid in the ground. This was done to lower the height of the tomato to easily reach
the fruits during the harvest. The tomatoes can reach a maximum height of 10 m.
In terms of irrigation and fertilizer application, the water and fertilizers were
mixed in big tanks that were connected to pressurized water pumps and to allow equal
distribution of water and fertilizer. A main pipe was connected to the water pump, where
secondary pipes or the pipes with drippers were connected. The drippers were laid near or
parallel the tomato plants where the liquid will form circular-form until each will meet.
The process is called fertigation. Before fertigation, the nutrition needed by the plant is
first analyzed.
Bumblebee Industry
Bumblebee has become a commodity in Israel because of the efficiency as
pollinator of thousands of hectares of greenhouses tomatoes. The economy Bio-Bee
located at Sde, Eliyahu, Beit Shean Valley, Israel has been mass producing bumblebee as
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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pollinators since 1990. In Israel, Bio-Bee Company supply pollination services to more
than 500 hectares and over 1000 clients. Also, bumblebee hives are exported to Europe,
Japan, Africa, and South America.
Tomato growers in Beit Shean Valley preferred to use bumblebee as natural
pollinator for their crops. Results shown in Table 1.
Table 1. The number of farmers using bumblebees as pollinator of tomato crops in each
Kibbutz of Beit Shean Valley
KIBBUZT TOTAL NO. OF FARMERS
NO. OF BUMBLEBEE USERS
Shluckot
6
6
Lofan
5
5
Kfar Ruppin
8
8
Yardenit
5
5
Sde Eliyahu
6
6
TOTAL 30
Rearing of Bumblebees
The bumblebees (Bombus terristris Linnaeus) or the large earth bumblebees are
reared in dark rooms or naturally, they dig and build their colony under the ground.
Kibbutz Sde Elyahu the pioneer of mass production has especial rooms in rearing
bumblebees. The rooms should be dark and were highly monitored to avoid the entry of
diseases that can cause damage to the starting colonies. Red lights are being used for
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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monitoring and checking the colonies, for bumblebees can not visualize red lights.
Unfortunately, the rearing house was not visited as it is restricted to visitors.
The Bumblebee Hive
Figure 5 shows the white and clean plastic box where the bumblebees from the
rearing house are placed for field distribution. The box has been especially designed to
provide maximum ventilation with the provision of numerous slits at the bottom of the
box, sidewalls and lids to allow airflow that helps the bumblebees quickly and efficient
remove dirt to keep the hive clean. Clean hives lengthen lifespan of the bees.
The bumblebees are provided with artificial food with the provision of a bag of
sugar-water with drinking apparatus in a separate unit within a cardboard covering
beneath the bee colony (Figure 6). The bumblebees obtain their food through a wick,
which transports the liquid from the bag into the brood compartment. Between the
plastic inner housing colony box and the food unit there is a thick layer of styrofoam
(about 2 cm) with a cotton wool covering the brood from above to provide maximum
insulation for the bumblebees.
Figure 7 shows the addition of dry pollen to the hive as a natural dietary
supplement. These are put at the center of the square part of the plastic inner lid with
slightly raised borders where the pollen eventually falls and become accessible to the
bees.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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Figure 5. The white box where the bumblebee colony are placed for field
use after they have been reared in dark room
Food
container
wick
Figure 6. Bag of water-sugar (food) and the drinking apparatus
pollen
Figure 7. Dry pollen is added to the hive as a dietary supplement
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Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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Arrangement of the Bumblebee hive
For final transport to the fields, the plastic hives are put inside a cartoon box
(Figures 8 and 9), provided with two openings that will serve as passage for the bees
when these are settled in the greenhouses. These openings are provided with shutter
(Figures 10 and 11).
Food
Wick
Figure 8. The top view with the water-sugar, Figure 9. The top view, food covered with
food court and food wick
styrofoam
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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Figure 10. The bee colony in polyethylene put Figure 11. The top and side view of the
through the cartoon box
bumblebee hive
Figures 12 to 14 show the full lowering of the plastic shutter to block totally both
the flight-holes during transport. If the colony is transferred to another plantation, one of
the holes will be kept open. This flight-hole allows the bees to enter and will not able to
exit. If the colony is used for pollination the plastic shutter is opened to the maximum to
expose the two flight-holes. These allow the bees to enter and exit in front of the hive.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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Figure 12. The flight-holes are closed
Figure 13. One flight-hole is opened
Figure 14. The two flight-holes are fully opened
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Transport of Bumblebee hive
Figure 15 shows sets of bumblebee colonies inside the packing house ready for
transport to various farms within Israel or for export. Bumblebee colonies are being
transported by close van truck with controlled temperature 28 ْ◌ C. During the transport
all the colony is closed and sealed.
Figure 15. Bumblebee colonies in cartoon hive box ready for market
Bumblebee Colonies Inside the Greenhouse
Fifteen (15) colonies of bumblebees are put inside a 1.5 hectares greenhouse
when the tomato flowers are about to bloom until the flowering stage will end. The
colonies are set up at least two (2) ft. from the ground with the provision of stands either
made of wood or metal materials (Figures 16 to 17). The colonies are set in the corner of
the greenhouse near the entrance and about three (3) ft. apart. The setting up of colonies
is done 9 o’clock in the morning. After the colonies are set up, the plastic shutter is lifted
to open the flight-holes so that the bees can enter in and exit from the hive respectively.
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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Figure 16. A bumblebee colony set on top of a table
Figure 17. The researcher showing a colony set on metal stand
Behavioral Characteristics of Bumblebee
Bumblebees are efficient pollinator of tomatoes for they are able to open the
tomato flower in order to be pollinated. They have a heavy body that upon clinging on
the flower, the latter bends allowing the flower-cone to open and also the falling of the
pollens. Apart from this the bumblebee vibrates its wings while bending its body causing
the shaking of the tomato flower. This activity enhances the falling of the pollen grains to
the stigma resulting to pollination. This kind of pollination system is called buzz
pollination.
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The following photos (Figures 18 to 20) show a tomato flower before and after
bumblebee visitation. A flower with scars caused by bumblebees eventually fruit set,
while flowers that has no scars, pictures that there was no visitation happened.
Figure 18. Unpollinated tomato flower
Figure 19. Bumblebee visiting a tomato flower
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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scars
Figure 20. A tomato flower with scars indicating successful pollination
Efficiency of Bumblebee Pollinator
Figures 21 to 22 show two tomato plantations grown in various media that were
pollinated by bumblebees. The crop in-charge claims that the use of bumblebees in
tomato production under greenhouses has increased the yield of export quality tomatoes
by 25% compared to manual pollination.
Figure 21. Tomatoes pollinated by bumblebees grown in soil medium
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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Figure 22. Tomatoes pollinated by bumblebees grown in artificial medium
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SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The study was conducted at Kibbutz Sde Elyahu, Beit Shean Valley, Israel from
January 2006 to July 2006 to observed tomato plantations inside the greenhouse, to
observed the behavioral characteristics of bumblebees that makes it efficient as pollinator
of tomatoes and to observed how colony is prepared and set in tomato plantations.
The tomatoes are planted in soil or artificial medium. The distance between plants
is 50 cm. and between plots is 1 m. The tomato is provided with supporting trails but the
lower stems are laid in the ground as they mature. Water and fertilizers are applied
through fertigation.
Bumblebees are attracted to the yellow flowers. They visit fully bloomed flowers
and as they cling to the petals that cover the pistil and it bends allowing the flower-cone
to open. The wings of the bumblebees continue vibrate causing the tomato flower to
shake and the falling of pollen grains into the pistil.
The bumblebee colony covered of white plastic box with ventilation, encased of
cartoon boxes provided with food. The colonies were transported in closed van truck. The
colonies were set near the entrance of the greenhouse with stand.
Conclusion
Bumblebee colonies are introduced as pollinators in tomatoes under greenhouse
condition in Israel. The bumblebees increased yield and improved fruit quality.
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Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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Recommendation
Based on the results and observations the researcher recommend that the use of
natural pollinators should be adopted in the country especially in promoting organic
farming and upholding the use of biological control.
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Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
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LITERATURE CITED
AVIEL, S. 2006. Biology of Earth Bumblebee: On USB. Available: Bio-Bee Beit Shean
Valley, Israel. [July 10, 2006].
MCDONALD, M. and G. NISBET. 2006. Highland Bumblebees: Distribution, Ecology
and Conservation. Retrieved February 10, 2007 from http://www.hbrg.org.uk
MCMASTERS JOHN H. 1989. The flight of the bumblebees and related myths
Entomological Engineering. Retrieved February 10, 2007 from
http://www.hbrg.org.uk
SUGDEN, E. A. 1997. Bumble Bee. Retrieved February 10, 2007 from
http://encarta.msm.com
Documentation on Bumblebees (Bombus terristris Linnaeus) as Pollinator of Tomato under
Greenhouse Condition in Israel. DELLIAS, ERIC C. APRIL 2007
Document Outline
- BIBLIOGRAPHY
- TABLE OF CONTENTS
- INTRODUCTION