WO1998021934A2

WO1998021934A2 - Pollination of crop plants by bumblebees

Info

Publication number: WO1998021934A2
Application number: PCT/IL1997/000378
Authority: WO
Inventors: Yanai Man; Amit Einav; Dan Weil
Original assignee: POLLINATION SERVICES YAD-MORDECHAI
Current assignee: POLLINATION SERVICES YAD-MORDECHAI
Priority date: 1996-11-19
Filing date: 1997-11-19
Publication date: 1998-05-28
Anticipated expiration: 1999-05-19
Also published as: WO1998021934A3; AU4963997A

Abstract

A method for pollination including placing in a field of plants to be pollinated a plurality of hollow compartments (6, 12) attached to each other, each compartment (6, 12) being populated by at least one bumblebee colony therein, and allowing the bumblebee colonies to forage among and pollinate the plants.

Description

POLLINATION OF CROP PLANTS BY BUMBLEBEES

FIELD OF THE INVENTION The present invention relates generally to pollination of crop plants by insects and particularly to methods and apparatus for pollination of crop plants by bumblebees BACKGROUND OF THE INVENTION

Development of fruit from seed-bearing (angiosperm) plants requires pollination, i e , the transfer of pollen from the anther to the stigma Typically there is a longitudinal slit in the anther, providing ample room for the pollen to leave the anther, such as by wind or by pollen-gathering insects, such as bees Flowers that can be self-pollinated will be fertilized by nearly every single visit made by a suitable pollinating insect However, for male-sterile flowers that require cross- pollination, only a small proportion of such visits can be expected to accomplish fertilization Although self-pollination is usually easier to achieve than cross-pollination, it is well known that cross-pollination is associated with plant vigor and mechanisms of species survival, and many flowering plants have various mechanisms that encourage cross-pollination

There is an increased tendency to exploit hybrid vigor to obtain greater yield of agricultural crops Parental cultivars are selected and crossed to produce seed that gives uniform and vigorous high-quality offspring when grown commercially The production of this hybrid seed crop needs special techniques to prevent self-pollination and to achieve cross- pollination, such techniques in several cases being manually applied

One technique that is enjoying increasing popularity is inbreeding male sterility to one of the parental lines (cultivars to be crossed), such as onion, tomato, cotton, and sunflower, for example This technique saves a lot of labor formerly invested in manual castration of the hermaphrodite female flowers, however, still requires much professional labor in collecting the pollen from the male-fertile flowers and transferring it to the stigmas of the male-sterile flowers Cross-pollination with insects has been tried However, as mentioned above, insects pollinate only when they transfer pollen from a male-fertile flower to a male- sterile one, and the commercial problem is to ensure that this happens often enough Cross- pollination with insects is feasible on the condition that both parental lines supply a suitable reward to visiting insects, and enough male-fertile plants are planted to produce sufficient quantities of pollen

Agricultural management of growing the parental lines, each line having different needs peculiar to its individual traits, is quite a problem One difficulty is that in many cases the male-fertile flowers are conspicuously more rewarding than the male-sterile ones

Even in those plants wherein the male-sterile flowers produce nectar, it is frequently found that the male-fertile flowers produce higher quantities than the male-sterile flowers, or have better quality or better secretion timing, thereby reducing the attraction of the insects to the male- sterile flowers The problem is worse in plants whose flowers produce only pollen and no nectar (e.g., tomatoes), so the male-sterile flowers give visiting insects no reward at all

Prerequisites for plant breeders attempting to breed parental lines adapted to insect pollination are to select lines which will a. Have floral reward of equal value b Have synchronized flowering periods c Have similar flowers, so insects cannot distinguish between the lines by colors, shapes or scents

Other factors may be taken into consideration in a plan of agricultural management, such as, wter aha, functional morphology of the flower For example, protruding stigmas in the flowers of the mail-sterile line of tobacco prevent efficient pollination by bees

Hybrid seed produced by cross-pollination sometimes has advantages over inbred seed. For example, in field beans (Vicia faba), plants from hybrid seed, as opposed to inbreeds, will produce seed readily by autopollination and give a greater yield even under low activity of pollinating insects Moreover, attempts to select auto-fertile varieties of economically important species have not generally been successful because inbreeding and loss of hybrid vigor have had a detrimental effect on yield Thus, the emphasis nowadays is to increase growing hybrid seeds, and studies have been made regarding use of insects as vectors for cross-pollination.

Studies have shown that whereas the feeding activities of most insects tend to diminish the amount of food available to succeeding generations, the foraging of pollinating insects increases seed production and thereby increases the amount of forage available for their successors The most important pollinating insects are solitary bees, bumblebees and honeybees, and indeed managed pollination is economically the most important function of bees worldwide Bees visit flowers to collect nectar and pollen They are attracted to flowers and recognize them by color, shape and odor Bees are able to learn the general shape of flowers, and the general form of plants but their visual acuity is small Honeybees are not very efficient cross-pollinators One reason is that honeybees are generally attracted to blossoms of constant color, shape and odor Even when hybrid seed is produced by crossing lines that are self-incompatible, e g , Brussels sprout (Brassica oleracea gemmifera), kale (Brassica oleracea acephala), and red clover (Trifolium pratense), honeybees tend to become conditioned to working one of the self-incompatible lines and do not move to another line In other words, the foraging honeybees tend to discriminate between the parental lines and do not readily cross pollinate between them For example, observations on the pollination of Brussels sprout to produce hybrid seed indicate that individual honeybees tend to move from plant to plant within each inbred line, rather than randomly between the two parental lines The ratio of "selfing" to "crossing" movements in honeybees on sprouts was found to be 30 1 and in 91% of observations of a honeybee leaving a flower, the bee landed on another flower of the same line

The bees tended to closely examine flowers of the alternative (less attractive) cultivar before leaving without landing, suggesting that odor was the most important distinguishing feature

Planting two self-incompatible cabbage cultivars as alternate plants in the same row, instead of in separate alternate rows, and pollinating with honeybees did not increase seed yield, so for convenience of cultivation and harvesting, planting in separate rows was recommended Honeybees tend to have a restricted foraging area, with the result that most pollen is transferred to only within a few meters from its source Bumblebees (genus Bombus, in particular the Bombus terrestris) can be much more efficient pollinators than honeybees, as will now be explained

About 8% of angiosperm plants, including such important crop plants as the tomato, eggplant and pepper, have anthers with only a small aperture or pore at the apex of the anther, making extraction of pollen from the narrow longitudinal depth of the anther difficult Bumblebees have a special pollen gathering technique, herein called "buzz pollination", which allows them to extract pollen from apically porous anthers and transport the pollen to stigmas The bumblebee grasps the anthers with its mandibles and tarsal claws and curls its body over the pores While hanging tightly onto the anther, the flight muscles of the bee transmit bursts of vibrational energy to the anther, the vibrational bursts being audibly detectable as a buzzing sound The vibratory motion causes the pollen to be extracted from the anther The pollen is harvested by adhering to the abdomen and other parts of the bee's body A relatively large amount of pollen can adhere to the bumblebee body because the bumblebee is larger and hairier than other bees For example, about 5 times the amount of pollen can cling to a bumblebee than to a honeybee Buzz pollination is also much faster than conventional insect pollen harvesting Bumblebees have other characteristics which make them more efficient pollinators than honeybees Their flower visitation rate is about double that of honeybees

Bumblebee pollination activity continues undisturbed even in low temperatures or inclement weather, or in enclosures, such as greenhouses Their navigation and orientation abilities are not disturbed under cover of radiation filtering sheets As a result of the abovementioned traits, for the same flower, bumblebees can harvest pollen about 400 times faster than a honeybee

Bumblebees have their own peculiar foraging habits and techniques which make them superior pollinators for certain crops (fruits and vegetables) which require cross pollination For example, honeybees tend to forage for pollen and nectar in one specific area of plants The honeybees work together as an organized swarm and fly directly to this area from their nest without foraging elsewhere along the way After collecting nectar and pollen, the honeybees fly directly back to the nest, again without foraging elsewhere The swarm of honeybees continues this process until all nectar and pollen have been harvested from the particular area, and only then do the bees leave and forage elsewhere, where they are led by scout bees In contrast, bumblebees do not forage in organized swarms Instead they tend to forage as independent wanderers, foraging for pollen and nectar from many varieties of plants and not necessarily in one specific area After collecting nectar and pollen, bumblebees will usually forage amongst other plants, scouting on their own, before flying back to their nest This random, haphazard style of foraging makes bumblebees efficient pollinators, especially for intercrossing pollination or hybridization

The use of bumblebees for intercrossing pollination or hybridization is known For example, bumblebees have been found to be efficient pollinator for tomato hybrid seeds production in Poland, as described in B Pinchinat et al , "Possibilities of Applying Bumblebees as Pollen Vectors in Tomato F, Hybrid Seed Production", Proc Fourth Int Symp on Pollination, Md Agric Exp Sta Spec Misc Publ 1 73-90

In another example, L A Berger et al, "Bombus spp as Pollinators of Male- Sterile Upland Cotton on the Texas High Plains", Environmental Entomology, 17(6) 789-794 (October 1988), discusses the use of bumblebees to transport pollen from male-fertile to genetic-cytoplasmic male-sterile flowers of hybrid cotton The authors of the article performed field observations of foraging behavior of bumblebees to pollinate hybrid cotton Natural bumblebee nests were collected and each colony was transferred to an individual wooden domicile Although wooden domiciles were acceptable for transporting the bees to the pollination site, the subsequent visitation of the bumblebees to the target field was low

There is still a need for improved techniques for commercially successful pollination of hybrid plants, especially for production of hybrid seed

SUMMARY OF THE INVENTION

The present invention seeks to provide improved apparatus and methods for pollination of crop plants by bumblebees

The unique beehive of the present invention is referred to in the specification and the claims as a multiple-colony bee domicile (MCB domicile) The MCB domicile preferably includes a plurality of hollow compartments attached to each other, each compartment having an internal volume sufficient for housing at least one bee colony therein Each compartment has one or more openings for allowing passage of one or more bumblebees therethrough The openings are preferably selectably openable, i e , a beekeeper may choose to open certain openings and keep other openings closed, so as to control traffic and passage of bees into the MCB domicile A hanging hook may be provided so that the MCB domicile may either sit on the ground or hang from a limb of a tree Any of the MCB domiciles of the present invention is particularly useful in bringing bumblebees to crop plant sites for pollination of flowers, such as tomatoes, avocados, eggplants and strawberries, for example By providing two or more colonies of bumblebees in each domicile, effective pollination is enhanced The MCB domiciles of the present invention may be particularly effective for pollination of hybrid varieties for production of hybrid seeds The present invention also provides a method for pollination of hybrid cotton, including allowing a plurality of bumblebee colonies to forage among male-fertile and male- sterile flowers of hybrid cotton lines The specific lines are mentioned hereinbelow Other agritechnical techniques are provide to increase the efficiency of pollination

The present invention also uses pheromones to trick insects, particularly bees, into incorrectly thinking that a certain plant is desirable for foraging thereat Pheromones are chemical substances produced by insects that influence the behavior and physiology of other members of their own species In honeybees, rich pheromone complexes are known and pheromone-mediated worker bee behavior has been well studied and documented For example, the worker-produced Nasonov pheromone is released at the nest entrance for orientation Beekeepers are all too familiar with the alarm-pheromone a stinging worker-bee gives off which alerts other bees and attract some of them to sting as well

In the present invention, a pheromone is placed on a plant to be pollinated, such as a male-sterile plant The pheromone provides false information to an insect responsive to the pheromone, i e , the insect is duped into thinking that it is desirable to forage at the plant The insect is thus taught to acquire an unnatural trait of foraging at the plant, thereby bringing pollen to the plant and pollinating it, something the insect would not have naturally done Once an insect has been duped into foraging at the plant, the insect may leave pheromone or some other forage-marking signal at the plant, so that more and more insects are attracted to forage at and pollinate the plant The method of the present invention is particularly advantageous for plants like tomatoes which lack a natural attractant, such as nectar, to lure an insect to forage thereat

It is important to note a distinction between the prior art and the present invention The prior art has used pheromones to attract insects to plants However, the prior art merely uses the pheromones to attract insects to plants which the insects naturally would have foraged at In contrast to the prior art, the present invention uses pheromones not only to attract insects but to teach false information to the insects The insect acquires an unnatural trait of foraging at a plant that provides little or no reward for its foraging endeavors Other agritechnical techniques, in accordance with other preferred embodiments of the present invention, are provided to increase the efficiency of pollination

The preferred pollinator in the present invention is the bumblebee However, in accordance with a preferred embodiment of the present invention, other insects are allowed to forage and pollinate in conjunction with bumblebees, the insects being selected from the group consisting of honeybee (Apis mellifera), Polistes dominulus, Lasioglossum malchurum, Halictus spp , Xylocopa pubescens, Anthophora spp , Osmia spp , Megachila spp , and Xylocopa violacea

There is thus provided in accordance with a preferred embodiment of the present invention, a multiple-colony bee (MCB) domicile including a plurality of hollow compartments attached to each other, each compartment having an internal volume sufficient for housing at least one bee colony therein Preferably each compartment has a selectably openable bee hole formed on an outwardly directed face for allowing passage of a bee therethrough In accordance with a preferred embodiment of the present invention, the compartments are generally hexahedral and adjacent compartments abut each other along mutually opposing faces Each compartment may be generally cubical in shape

Additionally the compartments are arranged in rows and columns The rows and columns may generally form a hexahedron

In accordance with a preferred embodiment of the present invention, the MCB domicile is formed in the shape of a hexahedron and includes eight compartments, each face of the hexahedron having four outwardly directed compartment faces

Additionally in accordance with a preferred embodiment of the present invention, each outwardly directed compartment face of the hexahedron has only two of the bee holes opened to allow passage of a bee therethrough, the two bee holes being diagonally spaced from each other, one bee hole being on one of the rows and the other bee hole on the other row Preferably each compartment has an internal volume of approximately eight liters

In accordance with a preferred embodiment of the present invention, the MCB domicile also includes an outer housing at least partially enveloping the plurality of compartments, the outer housing having a plurality of access holes formed thereon, each access hole being aligned with a corresponding bee hole to allow passage of a bee therethrough

Additionally in accordance with a preferred embodiment of the present invention, color coded markings are provided on a surface near at least one of the bee holes and the access holes

Further in accordance with a preferred embodiment of the present invention, a hanging hook is provided Preferably, the hanging hook is configured to substantially prevent rotation of the MCB domicile about a vertical axis A covering is preferably provided for substantially preventing entry of rain into the MCB domicile

There is also provided in accordance with a preferred embodiment of the present invention, a method for pollination including placing in a field of plants to be pollinated a plurality of hollow compartments attached to each other, each compartment being populated by at least one bumblebee colony therein, and allowing the bumblebee colonies to forage among and pollinate the plants The plurality of hollow compartments may be hung from a limb of a tree

There is also in accordance with another preferred embodiment of the present invention, a method for pollination of hybrid cotton including allowing bumblebees to forage among male-fertile flowers of hybrid cotton lines and pollinate male-sterile flowers of hybrid cotton lines, the cotton lines including at least one of the following male-sterile lines of Hazera (1939) Ltd of Israel designated as A- 195, A-48, A-

3, A-83, A-34, A-23, A-13, A-151, A-175, A-1 16, A-43, AI-60, A-66, AZ-426-2, AZ-290-1, A-870, A-715, A-664, A-881, A-87, A-164, A-4, A-184, A-155, A-153, A-14, AI-129 and

AI-125, male-fertile lines of Hazera (1939) Ltd of Israel designated as R-208, R-142,

R-58, R-86, R-1005 and RN-26, and female lines of Hazera (1939) Ltd of Israel for producing intraspecific hybrids designated as A-36, A-157, A-57, A-80 and A-158 It is appreciated that other lines may also be successfully pollinated with the methods of the present invention

In accordance with a preferred embodiment of the present invention, other insects are allowed to forage and pollinate in conjunction with the bumblebees, the insects being selected from the group consisting of honeybee (Apis mellifera), Polistes dominulus, Lasioglossum malchurum, Halictus spp , Xylocopa pubescens, Anthophora spp , and Syrphidae spp

Additionally in accordance with a preferred embodiment of the present invention, the method includes heterogeneously sowing rows of male-sterile and male-fertile plants over at least a portion of a planting field Further in accordance with a preferred embodiment of the present invention, the method includes coordinating use of pesticides and insects so as to allow insects to forage and pollinate without being affected by the pesticides This may include, for example, only using specific pesticides which are not harmful to the insects while pollinating, or not using any pesticides at all during pollinating, and then after pollinating, spraying or otherwise applying the pesticides As another example, the use of pesticides may be curtailed or delayed altogether until the insects reach a maturity and capability of foraging and pollinating, preferably together with bumblebees The insects may also be kept away from the field until pesticides have been applied, and then only afterwards are the insects introduced into the field for pollinating

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which Fig. 1 is a simplified pictorial illustration of a multiple-colony bee (MCB) domicile constructed and operative in accordance with a preferred embodiment of the present invention;

Figs. 2 and 3 are simplified pictorial and exploded illustrations, respectively, of an MCB domicile constructed and operative in accordance with another preferred embodiment of the present invention;

Fig. 4 is a simplified pictorial, partially cutaway illustration of a compartment of the MCB domicile of Figs. 2 and 3, constructed and operative in accordance with a preferred embodiment of the present invention; Fig. 5 is a simplified sectional illustration of opening a bee hole and access hole in the MCB domicile of Figs. 2 and 3, taken along lines V - V in Fig. 4; and

Fig. 6 is a simplified flow chart of a method for pollination in accordance with a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Reference is now made to Fig. 1 which illustrates a multiple-colony bee (MCB) domicile 5 constructed and operative in accordance with a preferred embodiment of the present invention.

MCB domicile 5 preferably includes a plurality of hollow compartments 6 attached to each other, each compartment 6 having an internal volume sufficient for housing at least one bee colony therein. Compartments 6 may be constructed of any suitable durable material, such as cardboard or plastic. Each compartment 6 has one or more openings 7 for allowing passage of a bumblebee therethrough. Openings 7 are preferably selectably openable, i.e., a beekeeper may choose to open certain openings 7 and keep other openings 7 closed, so as to control traffic and passage of bees into MCB domicile 5. A hanging hook 8 may be provided so that MCB domicile 5 may either sit on the ground or hang from a limb of a tree. Hook 8 may be used to attach compartments 6 together. Alternatively, compartments 6 may be attached to each other, fixedly or pivotally, by any other suitable fastener, such as screws, nails, clips, bands, straps or buckles, or may be bonded together with adhesive. Reference is now made to Figs. 2 and 3 which illustrate a multiple-colony bee

(MCB) domicile 10 constructed and operative in accordance with another preferred embodiment of the present invention. As seen in Fig. 3, MCB domicile 10 preferably includes a plurality of hollow, generally hexahedral compartments 12. Compartments 12 may be constructed of any suitable durable material, such as cardboard or plastic. Preferably compartments 12 are generally cubically shaped and have an inner volume of approximately 8 liters. It is appreciated that compartments 12 may be of other sizes and shapes, such as oblong, and may have any desired internal volume. A volume of 8 liters is preferred for optimum development of a bee colony in each compartment 12.

Reference is now additionally made to Fig. 4 which further illustrates one of the compartments 12. Each compartment 12 preferably has a selectably openable bee hole 14 formed on an outwardly directed face 16 for allowing passage of a bumblebee therethrough. Preferably bee hole 14 is stamped, cut or otherwise formed on face 16 as a pair of semicircular cuts 18 closely spaced and configured to be easily opened by pushing thereagainst, as will be further described hereinbelow with reference to Fig. 5.

As seen in Fig. 4, a plate 20 is preferably disposed in compartment 12 which may serve as a surface for bees to eat and populate on, for example. An upper face 22 of compartment 12 preferably serves as a lid for bee handlers to gain access to compartment 12.

Referring again to Fig. 3, it is seen that MCB domicile 10 is preferably constructed by arranging and stacking compartments 12 in rows and columns. The rows and columns of compartments 12 may form any prismatic shape, and preferably generally form a hexahedron. Most preferably MCB domicile 10 comprises eight compartments 12 arranged to form a regular hexahedron, i.e., a cube. It is seen that adjacent compartments 12 abut each other along mutually opposing faces 16. Preferably bee holes 14 are kept closed on the mutually opposing faces 16 so as not to permit passage of bees from one compartment 12 to another. Alternatively, bee holes 14 may be opened on the mutually opposing faces 16 to allow passage of bees from one compartment 12 to another. Only one bee hole 14 for each compartment 12 is preferably opened for passage of bees therethrough.

MCB domicile 10 preferably includes an outer housing 30 which at least partially envelops all of the compartments 12. Outer housing 30 preferably has a plurality of access holes 32 formed thereon, each access hole 32 being aligned with a corresponding bee hole 14 to allow passage of a bumblebee therethrough. In the illustrated embodiment, outer housing envelops the eight compartments 12, and outer housing 30 has four outwardly directed compartment faces 34 (Fig. 2). Preferably access hole 32 is stamped, cut or otherwise formed as a pair of semicircular cuts 33 closely spaced and configured to be easily opened by pushing thereagainst.

Compartments 12 may be merely placed inside outer housing 30 or alternatively, they may be attached to each other, such as with adhesive, before placement inside housing 30.

Reference is now made to Fig. 5 which illustrates opening of access hole 32 and bee hole 14. By pushing against access hole 32 and bee hole 14 in the direction of an arrow 40, a pair of disks 42 and 44 bounded by cuts 33 and 18, respectively in outer housing 30 and compartment 12, are detached and fall into compartment 12, leaving holes 14 and 32 opened and mutually aligned. Preferably bee hole 14 has a slightly larger diameter than access hole 32 to facilitate pushing out disks 42 and 44.

Referring again to Figs. 2 and 3, it is a particular feature of the present invention that only two access holes 32 and corresponding bee holes 14 are actually opened for one given outwardly directed compartment face 34. As seen in Figs. 2 and 3, the holes may be diagonally spaced from each other, or alternatively may be closely spaced in adjoining compartments as shown at a reference arrow 46. In the diagonal arrangement, only one passage is provided for bees to enter and exit through access holes 32 and bee holes 14 for a given row or column. The diagonal arrangement of bee holes 14 and access holes 32 also diminishes the chances of bumblebees stumbling into the wrong compartment and colony. To further help the bumblebees find their correct compartment, outer housing

30 preferably includes color coded markings 50 near and/or around at least one of the bee holes 14 and access holes 32. The color red should be avoided, because bees cannot generally see red, as is well known in the art.

In accordance with a preferred embodiment of the present invention, MCB domicile 10 also includes a covering 52 for substantially preventing entry of rain therein. Covering 52 may be flat or sloped and may be constructed of plastic with or without a protective coating. Preferably MCB domicile 10 is constructed with a hanging hook 54 which may be attached to covering 52, for example. Hanging hook 54 is preferably configured, such as being relatively wide, to substantially prevent rotation of MCB domicile 10 about a vertical axis 56. With the addition of hanging hook 54, MCB domicile 10 may either sit on the ground or hang from a limb of a tree.

Any of the MCB domiciles of the present invention is particularly useful in bringing bumblebees to crop plant sites for pollination of flowers, such as tomatoes, avocados, eggplants and strawberries, for example By providing two or more colonies of bumblebees, effective pollination is enhanced The MCB domiciles of the present invention may be particularly effective for pollination of hybrid varieties for production of hybrid seeds

In accordance with a preferred embodiment of the present invention, a method is provided for pollination of hybrid cotton The method includes allowing a plurality of bumblebee colonies to forage among male-fertile and male-sterile flowers of hybrid cotton lines, the cotton lines including at least one of the following male-sterile lines of Hazera (1939) Ltd of Israel designated as A-195, A-48, A-

R-58, R-86, R-1005 and RN-26, and female lines of Hazera (1939) Ltd of Israel for producing intraspecific hybrids designated as A-36, A-157, A-57, A-80 and A-158

The bumblebees may be housed in any kind of domicile, and preferably are housed in MCB domiciles constructed and operative in accordance with preferred embodiments of the present invention, as described hereinabove with reference to Figs 1 - 5

In addition, other insects may be used in conjunction with bumblebees These insects include, but are not limited to honeybee (Apis mellifera), Polistes dominulus,

Lasioglossum malchurum, Halictus spp , Xylocopa pubescens, Anthophora spp , especially

Anthophora acervorum, and Syrphidae spp

In accordance with a preferred embodiment of the present invention, the method of pollination of hybrid cotton further includes agritechnical techniques which increase the efficiency of pollination Instead of sowing individual, separate plots of male-sterile and male-fertile plants, both types of plants are sown heterogeneously together over at least a portion of the planting field "Heterogeneous sowing" in the specification and claims refers to any kind of sowing in alternating rows, such as one or more rows of male-sterile plants alternating with one or more rows of male-fertile plants Preferably there is a minimal space between the rows Since bumblebees forage randomly among the plants, the heterogeneous sowing of the plants is much more effective than conventional sowing in achieving a high degree of successful pollination Other agritechnical techniques may be used in accordance with another preferred embodiment of the present invention to increase the efficiency of pollination. Use of pesticides and insects is preferably coordinated so as to allow insects to forage and pollinate without being affected by the pesticides. This may include, for example, only using specific pesticides which are not harmful to the insects while pollinating, or not using any pesticides at all during pollinating, and then after pollinating, spraying or otherwise applying the pesticides. As another example, the use of pesticides may be curtailed or delayed altogether until the insects reach a maturity and capability of foraging and pollinating, preferably together with bumblebees. The insects may also be kept away from the field until pesticides have been applied, and then only afterwards are the insects introduced into the field for pollinating.

Reference is now made to Fig. 6 which is a flow chart illustrating a method for pollination in accordance with a preferred embodiment of the present invention.

A plant to be pollinated and a pheromone are selected. The plant is preferably a male-sterile plant which is to be pollinated by pollen collected and carried by insects from a corresponding male-fertile plant. The plant may lack a natural attractant to lure an insect to forage thereat. For example, the pheromone may be placed on tomatoes which lack nectar. Other plant families particularly suitable for the methods of the present invention are solanaceous (e.g., eggplants) , rosaceous (e.g., strawberries), cruciferous (e.g., Brussels sprouts), piperaceous (e.g., peppers), cucurbitaceous (e.g., cucumbers), and compositaceous (e.g., sunflowers).

The pheromone or forage-marking signal, the two terms being used interchangeably throughout the specification and claims, may be extracted from a gland, such as the tarsal glands or mandibular glands, of an insect. For example, the pheromone components may be selected from the tarsal glands of Bombus terrestris. These pheromone components are described in U. Schmitt, "Hydrocarbons in tarsal glands oϊ Bombus terrestris", Experientia 46 (1990), Birkhauser Verlag, CH-4010, Basel, Switzerland, pages 1080-1082, the disclosure of which is incorporated herein by reference. Examples of bumblebee tarsal gland pheromones are tricosane, pentacosane, heptacosane and nonacosene, although the present invention is not limited to these pheromone components. The pheromone components may also be manufactured synthetically.

Suitable species for attraction by pheromones include bumblebee (Bombus spp.), honeybee (Apis mellifera), Polistes dominulus, Lasioglossum malchurum, Halictus spp., Xylocopa pubescens, Anthophora spp., Osmia spp., Megachila spp., and Xylocopa violacea. The pheromone is placed on a portion of the plant to be pollinated. The pheromone teaches an insect responsive to the pheromone false information that the plant is desirable to be foraged thereat, thereby causing the insect to acquire an unnatural trait of foraging at and pollinating the plant. Once an insect has been duped into foraging at the plant, the insect may leave pheromone or some other forage-marking signal at the plant, so that more and more insects are attracted to forage at and pollinate the plant. In some species of insects, the insect may interact with other insects and teach them the false information, so that more and more insects forage at and pollinate the plants.

The attraction of insects to the plants may be further enhanced by illuminating a portion of the plant with ultraviolet light so as to make an otherwise hidden trait of said plant visible and attractive to an insect responsive to ultraviolet light. For example, researchers have found that if one illuminates flowers with ultraviolet light, such as flowers of the Rosa, Ranunculus and Lilium genera, one can actually see trails leading from the outer surface of the corolla directly to the nectaries of the flower, and bees follow these trails precisely. Other agritechnical techniques, in accordance with other preferred embodiments of the present invention, are provided to increase the efficiency of pollination. For example, at least two self-incompatible cultivars may be planted as alternate plants in the same row, and the insects are then allowed to forage thereamong. This technique is particularly suitable for the foraging habits of bumblebees. In addition, the method may include cultivating male-sterile and male-fertile plants to be generally of equal attraction to foraging insects. This may be accomplished by carefully planned irrigation, fertilization and spacing between plants. Branches and/or vines of male-sterile and male-fertile plants, such as tomatoes, may be intermingled to encourage the insects, particularly bumblebees, to forage among both kinds of plants to enhance pollination of the male-sterile flowers. Additionally or alternatively, both types of male-sterile and male-fertile plants may be sown heterogeneously together over at least a portion of the planting field. "Heterogeneous sowing" in the specification and claims refers to any kind of sowing in alternating rows, such as one or more rows of male-sterile plants alternating with one or more rows of male-fertile plants. Preferably there is a minimal space between the rows. Since bumblebees forage randomly among the plants, the heterogeneous sowing of the plants is much more effective than conventional sowing in achieving a high degree of successful pollination.

Use of pesticides and insects is preferably coordinated so as to allow insects to forage and pollinate without being affected by the pesticides. Preferably the pesticides are applied to create favorable foraging conditions, not only for insects which it is desired to attract to the target area, but also for natural pollination vectors that already inhabit the target area. This may include, for example, only using specific pesticides which are not harmful to the insects while pollinating, or not using any pesticides at all during pollinating, and then after pollinating, spraying or otherwise applying the pesticides. As another example, the use of pesticides may be curtailed or delayed altogether until the insects reach a maturity and capability of foraging and pollinating, preferably together with bumblebees. The insects may also be kept away from the field until pesticides have been applied, and then only afterwards are the insects introduced into the field for pollinating. It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art.

Claims

C L A I M S

What is claimed is

1 A multiple-colony bee (MCB) domicile (5,10) comprising a plurality of hollow compartments (6,12) attached to each other, each said compartment (6,12) having an internal volume sufficient for housing at least one bee colony therein

2 An MCB domicile (5,10) according to claim 1 wherein each said compartment (6,12) has a selectably openable bee hole (7,14) formed on an outwardly directed face for allowing passage of a bee therethrough 3 An MCB domicile (10) according to claim 1 or claim 2 wherein said compartments (12) are generally hexahedral and adjacent compartments abut each other along mutually opposing faces (16)

4 An MCB domicile (10) according to any of claims 1 - 3 wherein each said compartment (12) is generally cubical in shape 5 An MCB domicile (10) according to any of claims 1 - 4 wherein said compartments (12) are arranged in rows and columns

6 An MCB domicile (10) according to claim 5 wherein said rows and columns generally form a hexahedron

7 An MCB domicile (10) according to claim 6 and comprising eight compart- ments (12), each face (16) of said hexahedron having four outwardly directed compartment faces

8 An MCB domicile (10) according to claim 7 wherein each said outwardly directed compartment face (16) of said hexahedron has only two of said bee holes (14) opened to allow passage of a bee therethrough, the two bee holes (14) being diagonally spaced from each other, one bee hole (14) being on one of said rows and the other bee hole (14) on the other row

9 An MCB domicile (10) according to any of claims 1 - 7 wherein said bee holes (14) are closely spaced in adjoining compartments

10 An MCB domicile (10) according to any of the preceding claims wherein each said compartment (12) has an internal volume of approximately eight liters

11 An MCB domicile (10) according to any of the preceding claims and comprising an outer housing (30) at least partially enveloping said plurality of compartments (12), said outer housing (30) having a plurality of access holes (32) formed thereon, each access hole (32) being aligned with a corresponding bee hole (14) to allow passage of a bee therethrough.

12. An MCB domicile (10) according to claim 1 1 and comprising color coded markings (50) on a surface near at least one of said bee holes (14) and said access holes (32). 13. An MCB domicile (5,10) according to any of the preceding claims and comprising a hanging hook (8,54).

14. An MCB domicile (10) according to claim 13 wherein said hanging hook (54) is configured to substantially prevent rotation of said MCB domicile (10) about a vertical axis

(56). 15. An MCB domicile (10) according to any of the preceding claims and comprising a covering (52) for substantially preventing entry of rain into said MCB domicile

(10).

16. A method for pollination comprising: placing in a field of plants to be pollinated a plurality of hollow compartments attached to each other, each said compartment being populated by at least one bumblebee colony therein; and allowing said bumblebee colonies to forage among and pollinate said plants.

17. A method according to claim 16 and comprising hanging said plurality of compartments above ground. 18. A method for pollination of hybrid cotton comprising allowing bumblebees to forage among male-fertile flowers of hybrid cotton lines and pollinate male-sterile flowers of hybrid cotton lines, wherein said cotton lines are selected from the group consisting of: male-sterile lines of Hazera (1939) Ltd. of Israel designated as A-195, A-48, A- 3, A-83, A-34, A-23, A-13, A-151, A-175, A-116, A-43, AI-60, A-66, AZ-426-2, AZ-290-1, A-870, A-715, A-664, A-881, A-87, A-164, A-4, A-184, A-155, A-153, A-14, AI-129 and AI-125; male-fertile lines of Hazera (1939) Ltd. of Israel designated as R-208, R-142, R-58, R-86, R-1005 and RN-26; and female lines of Hazera (1939) Ltd. of Israel for producing intraspecific hybrids designated as A-36, A-157, A-57, A-80 and A-158.

19. A method according to any of claims 16 - 18 and comprising allowing other insects to forage and pollinate in conjunction with said bumblebees, said insects being selected from the group consisting of: honeybee (Apis mellifera), Polistes dominulus, Lasioglossum malchurum, Halictus spp., Xylocopa pubescens, Anthophora spp., and Syrphidae spp.

20. A method according to any of claims 16 - 19 and comprising heterogeneously sowing rows of male-sterile and male-fertile plants over at least a portion of a planting field. 21. A method according to any of claims 16 - 20 and comprising coordinating use of pesticides and insects so as to allow insects to forage and pollinate without being affected by the pesticides.

22. A method for pollination comprising: placing a pheromone on a plant to be pollinated, said pheromone teaching an insect responsive to said pheromone false information that said plant is desirable to be foraged thereat, thereby causing said insect to acquire an unnatural trait of foraging at and pollinating said plant.

23. A method according to claim 22 and further comprising allowing said insect to interact with other insects and teach said other insects said false information. 24. A method according to claim 22 or claim 23 and comprising placing said pheromone on a plant lacking a natural attractant to lure an insect to forage thereat.

25. A method according to any of claims 22-24 and comprising placing said pheromone on a plant lacking nectar.

26. A method according to any of claims 22-25 and wherein placing said pheromone comprises placing a pheromone extracted from a tarsal gland of an insect.

27. A method according to any of claims 22-26 and wherein placing said pheromone substance on a plant comprises placing a pheromone on a male-sterile plant which is to be pollinated by pollen collected and carried by insects from a corresponding male-fertile plant. 28. A method according to any of claims 22-27 and wherein placing said pheromone substance on a plant comprises placing a pheromone on a plant selected from the group consisting of solanaceous, rosaceous, cruciferous, piperaceous, cucurbitaceous, and compositaceous families.

29. A method according to any of claims 22-28 and also comprising illuminating a portion of said plant with ultraviolet light so as to make an otherwise hidden trait of said plant visible and attractive to an insect responsive to ultraviolet light.

30. A method according to any of claims 22-29 and wherein placing said pheromone substance comprises placing a pheromone to which is responsive an insect selected from the group consisting of: bumblebee (Bombus spp.), honeybee (Apis mellifera), Polistes dominulus, Lasioglossum malchurum, Halictus spp., Xylocopa pubescens, Anthophora spp., Osmia spp., Megachila spp., and Xylocopa violacea.

31. A method according to any of claims 22-30 and comprising planting at least two self-incompatible cultivars as alternate plants in the same row, and allowing insects to forage thereamong.

32. A method according to any of claims 22-31 and comprising cultivating male- sterile and male-fertile plants to be generally of equal attraction to foraging insects.

33. A method according to any of claims 22-32 and comprising coordinating use of pesticides and insects so as to allow insects to forage and pollinate without being affected by the pesticides.

34. A method of pollination comprising placing a pheromone extracted from a tarsal gland of an insect on a plant so as to attract an insect responsive to said pheromone to forage at and pollinate said plant. 35. A method of pollination comprising placing a synthetically produced pheromone on a plant so as to attract an insect responsive to said pheromone to forage at and pollinate said plant.

36. A method of pollinating tomatoes comprising placing a pheromone on a portion of a tomato plant so as to attract an insect responsive to said pheromone to forage at and pollinate said tomato plant.