CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority of United States provisional patent application no. 61/219,013 filed June 22, 2009, by applicants, the contents of which are hereby incorporated.

SUMMARY

[0002] Controlled release of insects can have benefits in agriculture and has been done for many years at smaller scales. For example it was shown that manually releasing predatory insects could help to control pest insects. One example of this is the two-spotted stink bug, Perillus bioculatus (Fab.) (Heteroptera: Pentatomidae), a predatory insect which can feed on the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera : Chrysomelidae), a common insect pest.

[0003] However, the relatively delicate, and living nature of insects caused many challenges which have likely impeded industrial use of insects as an alternative to the application of chemical pesticides, for example.

[0004] Some trials have been reported as successful at a somewhat limited scale with spreading microscopic insects such as lacewing eggs which could be mixed with vermiculite and handled as a powder by a hand carried device having a drum reservoir and a pneumatic blower for blowing portions of the mixture to selected areas. However, attempting to make such a method applicable to larger scales or to macroscopic insects (i.e. insects observable by the naked eye) caused many particular challenges.

[0005] A challenge thus resided in materializing a way to handle insects in a relatively large-scale manner while preserving their physical integrity, particularly where the insects are macroscopic. [0006] Considering the particular characteristics of macroscopic insects which were capable of moving to cover a given area, it was found that a source-point release of corresponding batches of the insects in accordance with a given pattern could allow substantially covering an entire field given the intrinsic mobility of the insects of the batches.

[0007] In accordance with one aspect, there is provided a method of distributing batches of insects sequentially in a plurality of distinct locations, comprising : providing a plurality of batches of insects in the form of a mixture of insects and carrier material in a plurality of corresponding independent containers; carrying the independent containers collectively over a field; while the independent containers are collectively carried over the field, sequentially emptying respective ones of the containers from the corresponding batch of insects at corresponding ones of the distinct locations, thereby distributing the batches of insects at the plurality of distinct locations on the field.

[0008] In accordance with another aspect, there is provided a system for dropping batches of insects on a field, the system comprising : a plurality of containers each closable to house a batch mixture of insects and carrier material therein in an aerated and sealed manner, and openable to allow emptying the contents of each container independently from the other containers; and a vehicle collectively carrying the plurality of containers.

[0009] In accordance with another aspect, there is provided a plurality of batches of insects for agricultural distribution, each one of the batches being provided in the form of a mixture of a droppable, aerated, particulate and biodegradable carrier material and insects clung onto the carrier material, each one of the plurality of batches being provided inside a corresponding container, each one of the containers having a corresponding lower door openable independently from the doors of the other containers to allow dropping of the corresponding batch by the effect of gravity.

DESCRIPTION OF THE FIGURES

[0010] In the appended figures, [0011] Fig. 1 is schematic view showing a source-point distribution pattern;

[0012] Figs. 2 A and 2B are oblique views showing an example of a container for receiving a batch of insects for source point distribution;

[0013] Figs 3 is an isometric view showing a system for handling containers such as shown in Fig. 2 A and 2B; and

[0014] Figs. 4A to 4B are successive schematic views showing the opening of a container, release of the batch of insects, and closing of the container as it is handled by the system of Fig. 3.

DETAILED DESCRIPTION [0015] It was found that small macroscopic insects, such as the two-spotted stink bug at the N2 stage (Perillus bioculatus 2 ^nd instar nymphs) for example, could be mechanically handled when mixed with a suitable carrier material. At the N2 stage, the immature two- spotted stink bug can already move by walking but do not yet have wings. Such insects can cling onto the carrier material which can then be handled in a larger quantity than if directly handling the insects individually. Subsequently to releasing the mixture of insects and carrier, the carrier will typically be left on the field, so biodegradable materials, or materials having fertilizing characteristics, can be favoured. Dusty materials may not be suitable in some embodiments because the dust may tend to cover the insects and hinder movement or vitality thereof. Finally, aeration should be preserved, and the material should resist compaction in a manner to preserve movement ability for the insects. Of many materials tested, wood chips and pop corn were found adequate. Vermiculite, perlite, hay, straw mulch, sawdust, charcoal, peat and cedar mulch were not found adequate, at least for handling Perillus bioculatus N2 nymphs. Thin wood chips and popcorn tended to show comparable satisfactory handling characteristics for Perillus bioculatus N2 nymphs.

[0016] Distributing a mixture of insects and carrier material on a field can now be done source point release, i.e. releasing a plurality of batches each having a number of insects mixed with carrier material at distinct locations to harness the mobility power of the insects to cover a given area on the field. A source-point release can be effected in accordance with a predetermined pattern which can depend on the type and quantity of insects, their mobility or area they can be deemed to cover after source-point release, and the intended use of the insects.

[0017] Fig. 1 shows an example of a predetermined distribution pattern in accordance with source-point release. The vertical lines 10 schematize rows of crops having an insect pest infestation. In this example, the crops are potato crops and the insect pest is the Colorado potato beetle (Leptinotarsa decemlineata) at a high level of infestation which is to be treated with Perillus bioculatus N2 predator nymphs.

[0018] In this illustrative example, the spacing 11 between the rows 10 of potato crops is of 90 cm. A survey of the field can be realized to determine an indication of infestation of the field by the insect pest, including information concerning a concentration of the insect pest and their average stade of development for instance. This information can then be used to determine an amount of predatory insects required to significantly affect the population of insect pest, such as by using empirical data for example.

[0019] To determine the pattern of source-point release, it is also relevant to know the degree of mobility of the predatory insects, such as their dispersal rate, in order to estimate the area they can be deemed to cover over a reasonable amount of time.

[0020] In our example, with Perillus bioculatus N2 nymphs, the dispersal rate was estimated to 0.23 m/day along the rows, and 0.17 m/day perpendicular or across the rows, and the area 12 to cover with each batch of insects was selected in a manner that its perimeter would be reached by the insects within about 10 days. Henceforth, in this example, it was determined to space the source points 14 by a distance 15 of about 5 m along the rows 10 (which corresponds to roughly 17 potato plants), and to space the rows 10 of source points 14 by two intermediate rows 16. The areas 12 then averaging about 14 m ² were thus selected so as to be substantially covered by the predator insects in about 10 days. [0021] From the information obtained by the survey, a ratio of 2 predator insects per potato crop was determined to be appropriate to treat the detected level of infestation. In this example, this corresponded to about 100 predator insects by batch dropped at each source point.

[0022] Now, to release such batches at such source points on a field in a relatively efficient manner was quite a challenge. First of all, because the insects are living and mobile, they are much more complex to handle than inert chemicals. For instance, the survival rate of the insects would be quite low if they were simply packed into a hopper alone. As discussed above, providing a given concentration in a given amount of carrier material made the insects more manageable, but handling a relatively large quantity of such a mixture could rapidly lead to a high level of disparity - i.e. unevenness of the concentration of the insects in the mixture depending on the selected area in the large quantity - given the fact that the insects can tend for example to migrate in the mixture toward a given area and/or to tend to move to the bottom of the container in which they are handled. Henceforth, if handling a large quantity in a drum for example, taking "scoops" of the mixture and dropping them as batches at the source points could lead to some of the source points receiving much less than the desired amount of insects, and others perhaps receiving a lot more than the desired amount.

[0023] This challenge was addressed by providing the batches insects directly into corresponding relatively small-sized containers before going to the field. It was much easier to control the quantity of insects in such relatively small-sized containers than attempting to scoop an appropriate quantity of insects in a larger drum or hopper.

[0024] The mechanical realization which is described below was thus developed to provide such a source point release in a highly automated manner. The particular example will be understood to be provided solely for purposes of illustration and that adaptations may be required for alternate embodiments. [0025] The mechanical release of the predators can be effected with the 100 predators mixed with a carrier material, such as the thin wood chips or popcorn discussed above for example, in a container 18 such as illustrated in Figs 2A and 2B, which can be opened to release the batch onto the ground under the effect of gravity at the desired source point. It was aimed that for releasing 100 Perillus bioculatus N2 predator nymphs at a given source point, the container 18 should have about 200 cm ³ volume, and be both aerated to allow insect respiration and sealed to prevent the insects from escaping. It can thus have openings which are smaller than the insects themselves.

[0026] Solid walls 20 were preferred to mesh even though they typically do not offer aeration because, it favoured a higher rate of insect release - the insects having a tendancy to cling to mesh if mesh was used for the walls. A cylindrical peripheral wall 20 such as the one shown was preferred to a square configuration because it avoids the occurrences of corners which constitute areas where insects have been observed to cling. Due to the use of solid walls, an aerated seal 22 was used between the container wall 20 and its lower door 23, of a material such as open cell foam, and this was found to both prevent insect escape and provide satisfactory aeration in the selected application. The top 24 of the container 18 is closed, and can optionally be provided with suitable aeration, for instance. The lower door 23 is sloped, which was found to favour the release. A 10° or higher slope was favoured, although the lower door can also be horizontal in alternate embodiments. Further, in this embodiment, to adapt the container 18 to the system which will be detailed further below, the lower door 23 is openable by pivoting (by way of a hinge in this case), and is spring- biased to the closed position shown - this was achieved using a spring-mounted hinge 26 in this embodiment - and has a door protrusion which extends both longitudinally and laterally on both sides to define two door protrusion edges 28a, 28b, and a mating member 30 provided here in the form of a hook, the purpose of which will appear from further reading below.

[0027] Handling and releasing the insects by hand at a large scale of crop production could be economically not viable, especially given the costs associated to labour in Canada or the United States, for instance. Henceforth, to allow distributing insect batches in a satisfactorily high number of source points for industrial agricultural purposes, there was a need to have a number of such containers carried by a vehicle, and sequentially emptied at each point of the predetermined pattern.

[0028] Fig. 3 illustrates a prototype of a system 32 which can be adapted to achieve this function. The system 32 includes a frame 34 which can be carried by a vehicle over a field. A conveyor 36 and more particularly, a chain conveyor 36a in this example, is mounted to the frame 34. A number of containers 18 can be mounted in an interspaced manner along the conveyor 36. More particularly, four equally interspaced containers were mounted to the conveyor in this prototype system although only one is shown in the illustration. It can be understood that room for more containers can be made by making the conveyor longer, for instance, and that to maintain a longer conveyor manoeuvrable, it can be configured into a zig-zag configuration in an alternate embodiment. The conveyor can be programmed to stop between source points to allow positioning the containers closer to one another.

[0029] Still referring mainly to Fig. 3, an abutment 38 is placed at a fixed position relative to the frame 34, in interference with the path 40 along which the containers 18 are carried by the conveyor 36. Henceforth, when the time has come to open a given one of the containers 18 at a given source-point along the predetermined pattern (see Fig. 1), the conveyor 36 carries the container 18 in a manner that the lower door 23 of the container 18 is brought into contact against the abutment 38 and is pivoted open by the abutment 38 as the container 18 is being carried by the conveyor 36. More particularly, the abutment 38 includes an inner portion 38a designed to engaged the inner door protrusion edge 28a, and an outer portion 38b designed to engage the outer door protrusion edge 28b (Fig. 2A and 2B) The releasing action will be detailed further down.

[0030] Still referring to Fig. 3, in the prototype, the conveyor 36 is driven by an electric motor 40 and will be understood to separately and independently open the lower doors of the containers. Further, it will be noted that the container 18 are removably held to the conveyor 36 by an appropriate attachment. In this case, the conveyor 36 has a receiving member 42 which is designed to detachably receive the mating member 30 of the containers 18. In this particular embodiment, the receiving member 42 is provided in the form of a channel shaped bracket 42a to downward-slidingly receive in a snug manner a downwardly projecting arm 30a of the hook shaped mating member 30 of the container 18 for the container 18 to be securely held during normal use of the system 32. The containers 18 can thus be removed in order for them to be filled with the corresponding batches of insects, and then be positioned back onto the conveyor 36 to ready them for distribution of the insects on the field. Finally, the abutment has a number of notches 44 in this case which are designed to make the container 18 vibrate to favour full dropping of the insects as will now be detailed.

[0031 ] Referring to the successive views of Figs 4A to 4D, the container 18 filled with a batch of insects provided in the form of a mixture of insects and carrier material, can be seen to approach the abutment 38 as it is conveyed by the conveyor (not shown). At Fig. 4B, the abutment comes into contact with the door 23 which is pushed by the abutment to pivotally open and release the batch 50 to the ground. The door 23 is pivotally biased to the closed position by the spring-mounted hinge 26. At Fig. 4C, as the container 18 is carried further, the pivotally-biased door 23 comes into contact with the notches 44 in the abutment, and the spring action of the door 23 swings the door 23 against the notches which causes a shaking effect on the container 18, acting to dislodge any insects which may still be clung in the container 18. Finally, at Fig. 4D, once the container 18 has passed the abutment 38, the door 23 is freed and thus becomes free to close under the bias caused by the spring hinge.

[0032] The system can be made to be operable for instance by the operator of a tractor which tows it. Depending on the particulars of the application, the conveyor can be designed either to be intermittently operable, such as by having a timer which indicates a specific period of time between the source points, or with an odometer which determines a given distance between the source points, for the conveyor to be operated at precisely the right timing, to name a few examples. [0033] As indicated above, it will be understood that the illustrated embodiment described above is provided illustrative purposes only, and that many other variants are possible in alternate embodiments. For instance, in alternate embodiments, the containers can be at a fixed position and the abutment can be mounted on a conveyor and coming to abutment with the containers. Further, still alternately, a plurality of independent actuators can be used on each container, where the containers with their independent actuators can be used on another type of vehicle, such as an aircraft or helicopter for instance.

[0034] Although cylindrical containers are used in the illustrated embodiment, it will be understood that other shapes can be used as well, such as square for instance. Further, in some embodiments, it may be preferable that the batch of insects be assisted to be dropped such as by mechanically pushing or blowing for instance.

[0035] It will also be noted that the mechanical distribution system described above is specifically adapted for Perillus bioculatus N2 nymphs in a quantity and concentration to treat a Leptinotarsa decemlineata (Colorado potato beetle) insect pest infestation of potato plants. Distributing insects of another type, of a different stage, or for different purposes may or may not require specific adaptations to the mechanical distribution system. For instance, the spined soldier bug, Podisus maculiventris (Say) (Heteroptera: Pentatomidae) is another predatory insect which can walk and can be used in treating Colorado potato beetle infestation, and can be distributed using the exemplary mechanical distribution described herein. Crawling insects can also be distributed using the system, for example. It will be understood that other predatory insects can be desired to distribute for other types of insect pests, which can infest other plants than potatoes, such as strawberry or eggplants for instance, and that the morphology and size of such other insects to distribute can call for appropriate adaptations of the system. Finally, although the described embodiment involves the general case of distributing an insect which is predatory to a given insect pest, it will be understood that other uses can be made to insects beneficial to a field, and alternate embodiments are not specifically limited to the distribution of predatory insects. Also, a batch of insects with carrier material for distribution can include more than one species of insects and/or a given species of insects at more than one stage. Also, other carrier materials disclosed above for illustrative purposes can be favoured in alternate embodiments.

[0036] For illustrative purposes, the system described above was carried by a tractor over the field, to the different points of the pattern. However, other vehicles can be used as well in alternate embodiments, such as a helicopter or a man-propelled vehicle for instance. Still alternately, the batches of insects can be carried without a vehicle.

[0037] The scope is thus indicated by the appended claims.