WO2003086067A1 - Method for production, raising and conditioning of entomophagous insects of use in biological control - Google Patents

Abstract

The invention relates to a method for production, raising and conditioning of entomophagous insects comprising the following steps: (a) deposition of G0 adults on a glabrous vegetable material of little height, (b) transfer, before the emergence of G1 larvae, of the glabrous vegetable material to a ventilated raising box, (c) emergence and raising of the G1 larvae to the adult state, (d) optional storage of the mature G1 adults and (e) harvest of the G1 adults by narcosis.

Description

 PROCESS FOR THE PRODUCTION, BREEDING, AND PACKAGING OF STORAGE INSECTS USEFUL FOR BIOLOGICAL CONTROL

The present invention relates to the field of biological control against plant pests using insects and more particularly a process for the production, breeding and co nd ition of cultivation aids, such as insects entomophages.

The development of biological pest control has been made possible thanks to the development of industrial production methods for insect and mite auxiliaries. These productions of useful organisms are most often made from prey or natural hosts, prey or replacement hosts or, more quickly, from prey or artificial hosts. The profitability of such productions is not always obvious because, on the one hand, they require heavy investments due to the biological processes which must be controlled and, on the other hand, the automation of the productions is difficult, if not impossible. In addition, the productivity of such farms is often low.

In the context of biological control, the Applicant is more particularly interested in the use of Macrolophus caliginosus. This entomophagous bug is used in biological control on greenhouse crops, in particular on tomato and eggplant crops. Macrolophus caliginosus feed on whitefly and whitefly eggs and larvae, which is the main pest of greenhouse tomato crops. In addition, due to their polyphagous nature, Macrolophus caliginosus can also feed on aphids, lepidopteran eggs, of mites, etc. and therefore be used in the biological control of these pests. Thanks to their qualities mentioned above, Macrolophus caliginosus have become, in recent years, one of the main auxiliaries for biological control in most European countries.

The usual process for producing Macrolophus caliginosus for use in biological control consists in using tobacco plants placed in cages (70 x 70 x 80 cm for a tobacco stalk) or in greenhouse compartments. The usual process for producing Macrolophus caliginosus therefore requires the use of large areas and volumes. Macrolophus caliginosus (so-called G0 laying adults) lay eggs on tobacco plants and embryo development of the new generation also takes place on these plants. To feed the Macrol ophus cal i ginos us, we use a substitute prey, butterfly eggs (flour moth eggs, Ephestia kuehniella) which are sprinkled on the tobacco leaves.

This method makes it possible to obtain 1000 to 1500 insects (adult Gl) from a starting inoculum of about 250 Macrolophus cali ginosus (adult G0). The starting inoculum is not reused for other production waves. Indeed, chemical (C0 ₂ ) or mechanical recovery of adults G0 is too delicate, too long and requires too much cost (labor, quantity of chemicals to be used in cages or greenhouses, etc.) to be implemented.

This method has other drawbacks and shortcomings. The time required for the production of Macrol ophus cali ginosus is long since it is 12 weeks mainly because of the time required for the production of tobacco used for the implementation of this method.

In addition, the harvest of M a c r o l o p h u s c a l i gi n o s u s (adult Gl) is done by individual aspiration using the slight tendency of these insects to phototropism. The use of an anesthesia is difficult under the conditions of production and breeding of Macrolophus caliginosus in a cage or in a greenhouse on tobacco plants. Indeed, after an anesthesia, the Macrolophus caliginosus fall and stick to the tobacco leaves because of the sticky bristles that this plant presents. Consequently, this production method involves numerous and long handling operations to recover Macrolophus caliginosus.

After recovery, Macrol oph u s caliginosus are packaged in boxes or bottles for shipping. During this conditioning, vermiculite or friesian (wood or paper) are added to the boxes and flasks which also contain a tobacco fragment with some Ep h e s t i a kuehniella eggs. However, vermiculite prevents the movement of insects which can die if the storage time is long, and the Frisian makes it difficult to let go of the insects. Under such conditions, to deliver Macrolophus caliginosus in good condition, the storage time must not exceed 5 to 7 days. Storage must be carried out in the dark and at a temperature between 7 and 10 ° C. Failure to comply with these conditions may result in a reduction in the quality of the Macrolophus cal i ginosus offered.

The quantities of Macrolophus caliginosus per package are of the order of 250 individuals among which may be a certain number of larvae. These larvae, when released, will not necessarily meet the necessary conditions (food, temperature, light, humidity, etc.) for their further development and will not systematically give adults Gl.

Given these various elements, the investment and operating costs are high and do not allow us to envisage sufficient profitability of large-scale production.

Thus, the work of the Applicant has enabled the implementation of a process for the production, breeding and packaging of Macrolophus caliginosus which solves the above problems. In addition, the process for the production, breeding and packaging of Macrolophus caliginosus implemented by the Applicant is remarkable in that it does not apply exclusively to this single predatory bug, but is also usable for the production, breeding and conditioning of other entomophagous insects and in particular for the production, breeding and conditioning of predatory bugs belonging to Mirides and Anthocorides and also for the production, breeding and packaging of predatory thrips. Thus, by way of example and without limitation, the entomophagous insects which can be produced, reared and conditioned according to the process of the invention are Orius spp, Anthocoris spp, Macrolophus caliginosus, Xylocoris spp, Franklinothrips vespiformis .... The present invention therefore relates to a process for the production, breeding and conditioning of entomophagous insects comprising the following stages: a) laying of GO adults on small hairless plant material, b) transfer, before the emergence of the larvae Gl, small hairless plant material in ventilated rearing boxes, c) emergence and rearing of larvae Gl to the adult stage, d) possibly storage of mature Gl adults, e) narcosis harvest of adults Gl and conditioning .

The choice of the small hairless plant material used in the process of production, breeding and conditioning of entomophagous insects, object of the invention and replacing the tobacco used in the usual processes will be made according to a certain number criteria. Indeed, the hairless plant material must:

- have a low production cost,

- be rapidly productive, allow entomophagous insects to be able to insert their eggs into this plant material (plant material with many veins or thick plant material),

- present less risk of development of diseases and pests compared to tobacco. The fact that the small plant material used is hairless makes it possible, when recovering adults G0 or Gl by narcosis, to prevent them from sticking to the bristles that non-hairless plant material could present. Any small hairless plant material meeting the above conditions can be used in the context of the present invention. Advantageously, the small hairless plant material used in steps (a) and (b) of the process which is the subject of the invention is chosen from pelargonium, beans, cucumbers, succulents, etc.

Preferably, the small hairless plant material used in steps (a) and (b) of the process which is the subject of the invention is pelargonium. In addition, the pelargonium used in steps (a) and (b) of the process which is the subject of the invention is advantageously in the form of cut stems coated with wax or nutritive agar, which preserves the quality of the pelargonium. The use of small hairless plant material makes it possible to reduce the areas necessary for the production and rearing of entomophagous insects. This breeding can thus be carried out in cages or small boxes, which makes it possible to reduce the manpower necessary for the feeding and the harvesting of the entomophagous insects (larvae and adults Gl). In addition, the industrialization of these tasks is possible.

Step (a) of the process of the invention normally lasts one week. However, step (a) is carried out in a controlled ventilated environment, the ventilation used being able to be passive or active. The use of a controlled ventilated environment avoids confinement which could be detrimental to the survival of GO adults. In addition, by modifying the parameters (brightness, humidity and temperature) of this controlled ventilated environment, it is possible to accelerate or slow down the development of the eggs of entomophagous insects. and therefore to shorten or increase the duration of step (a) of the process which is the subject of the invention.

Step (a) of the process of the invention is remarkable in that it makes it possible to use entomophagous laying insects (adults GO) several times. Indeed, the entomophagous insects (adults GO) are recovered by a light narcosis, the insects do not stick to the hairless plant material of small size after narcosis. Entomophagous insects (adults GO) thus recovered can be used on new laying supports (glabrous plant material of small size) and this, on several waves of production of entomophagous insects (generation Gl). In addition, the fact that the small hairless plant material carrying the eggs of the entomophagous insects is transferred, before the emergence of the GL larvae, in ventilated breeding boxes (step (b) of the process of the invention) avoids that, during the recovery by narcosis of the entomophagous insects (adults G0), larvae Gl are also not recovered and / or injured.

During step (a) of the process, the adults G0 are nourished by returning to the hairless plant material of small size from the natural food. A person skilled in the art knows, depending on the high entomophagous insect, the quantity of food which should be placed on the hairless material. The natural food advantageously used is butterfly eggs and, more particularly, eggs of Ephestia kuehniella. Step (b) of the process of the invention corresponding to the transfer, before the emergence of the G1 larvae, of glabrous plant material of small size in ventilated breeding boxes is very rapid and this step can also be industrialized. Preferably, the transfer of small hairless plant material is carried out 24 hours before the onset of emergence.

The ventilated breeding boxes used in step (b) are advantageously placed in air-conditioned rooms. Thus, temperature control in air-conditioned rooms makes it possible to control the moment of emergence of the GL larvae (step (c) of the process) and thus to bring about a wave of production of entomophagous insects on a precise harvest date . Table 1 below presents the operating conditions of steps (a) and (b) for two types of entomophagous insects which are the Ma cro l oph us cal i gi nos us and the Orius laevi gatus. These values should not be considered as limiting the scope of the invention but as examples of implementation of the latter.

Table 1

During the cultivation of the Gl larvae in step (c) of the process of the invention, hairless plant material is regularly added to increase the distribution surface of the Gl larvae and natural or artificial food for these larvae is regularly distributed on this material. The natural food advantageously used consists of butterfly eggs and, more particularly, eggs of Ephestia kuehniella.

The process which is the subject of the present invention may have a possible storage step (step (d)). This step consists in keeping the adults GL in ventilated breeding boxes in air-conditioned breeding rooms. The temperature and light control in the air-conditioned breeding rooms makes it possible to slow down or speed up the batch, which was not feasible in the usual greenhouse processes without loss or manipulation.

The recovery of adults Gl by narcosis in step (e) of the process which is the subject of the present invention makes it possible to recover 100% of the production. Indeed, as indicated above, entomophagous insects, after narcosis, do not stick to the hairless plant material.

The method of conditioning adult Gl in step (e) of the process which is the subject of the invention consists in keeping adult Gl in a mailing box containing a given support and a plant material allowing the entomophagous insects to drink. Food is advantageously attached to this plant material. The plant material which can be used in the conditioning stage (e) can be any hairless plant or not, the only condition being that it can supply water to the entomophagous insects during their conditioning. By way of examples and in a non-exhaustive manner, mention may be made, as plant material which can be used in the context of the conditioning step (e), of a bean, a part of succulents, a stem or a leaf of pelargonium. Food can be attached to this hairless material by any means known to those skilled in the art and not affecting the survival of entomophagous insects. By way of example and in a non-exhaustive manner, eggs of Ephestia kuehniella can be glued with water to said hairless material.

The support given advantageously used is popcorn kernels allowing individuals to move for drinking or food and also serving as a regulation in terms of humidity. The use of a such support is described in French patent application No. 96/03513. The teaching relating to popcorn kernels of this French patent application is incorporated by reference in the present invention. In addition, in the same packaging, that is to say in the same mailing box, the popcorn kernels can be put in fillets. The nets advantageously have a sufficient mesh for the passage of insects. These nets are made of a material which is not detrimental to the survival of the entomophagous insects, such as paper, plastic, etc. The plant material allowing the entomophagous insects to drink and the food can be found inside as well as the outside of these nets. Each fillet corresponds to a dose (sub-packaging) and each outbox can contain several nets. The Applicant has verified that the insects packaged in a box containing several fillets are distributed homogeneously in these fillets. The usual methods of conditioning entomophagous insects use a single conditioning containing between 200 and 500 individuals (depending on the species of entomophagous insects). The user must then make his own fractionation according to the number of individuals he needs. The packaging method which is the subject of the present invention, with sub-conditioning, makes it possible to easily create doses of a few tens of insects from boxes of several hundred insects. This system allows the user to have a few tens of entomophagous insects without having to handle the entomophagous insects, to distribute the entomophagous insects more adequately in the crops to be treated. These different forms of packaging allow storage of Gl adults for 1 to 2 weeks. When delivered after this period, Gl adults are in very good condition and these forms of packaging do not cause any loss.

An additional advantage of the process for the production, breeding and conditioning of the entomophagous insects object of the invention is the possibility of obtaining an additional G2 generation of entomophagous insects.

In fact, the plant material placed in the packaging and sub-packaging allowing the insects to drink can also serve as a laying medium for a few days before shipment. A generation G2 of small larvae can therefore gradually leave the conditioning well before the appearance on treated crops of the generation resulting from the reproduction of adult Gl released. This additional G2 generation of entomophagous insects from packaging can move towards the treated plant in the "sensitive" time interval of the pest control strategy. The "sensitive" time interval corresponds to the period during which the target insects of the released auxiliary develop before the predator is installed, this period being up to 5 to 6 weeks.

The emergence of this additional G2 generation of entomophagous insects is however only possible if the necessary conditions (temperature, light, humidity, etc.) for the further development of the G2 larvae are present during the release. The process of production, breeding and conditioning of the entomophagous insects object of the invention is advantageously used for entomophagous insects chosen from the predatory bugs belonging to the Mirides and Anthocorides and the predatory thrips. Advantageously, the entomophagous insect to which the process which is the subject of the invention applies is Macrolophus caliginosus.

The present invention also relates to a device capable of being implemented in the process of production, breeding and packaging of entomophagous insects, object of the present invention. Advantageously, the invention relates to a dispatch box containing a given support enclosed in at least one net and a plant material allowing the entomophagous insects to drink. Food is advantageously attached to this plant material.

The support given advantageously used is popcorn kernels, as described in French patent application No. 96/03513.

The nets advantageously have a sufficient mesh for the passage of insects. These nets are made of a material which is not detrimental to the survival of the entomophagous insects, such as paper, plastic, etc. The plant material allowing the entomophagous insects to drink and the food can be found inside as well as the outside of these nets. The plant material usable in this mailing box can be a bean, a rod or a pelargonium leaf or other.

Table 2 below presents the characteristics of a mail box according to the present invention and usable with Orius spp, Anthocoris spp, Macrolophus caliginosus, Xylocoris spp, Franklinothrips vespiformis, etc ...

Table 2

Claims

1) Process for the production, breeding and conditioning of entomophagous insects comprising the following stages: a) laying of GO adults on small hairless plant material, b) transfer, before the emergence of the GL larvae, of the material glabrous plant of small size in ventilated rearing boxes, c) emergence and rearing of GL larvae until the adult stage, d) possibly storage of mature Gl adults, e) narcosis harvest of adult Gl and conditioning. 2) Method according to claim 1, characterized in that the small hairless plant material used in steps (a) and (b) is chosen from pelargonium, beans, cucumbers, succulents. 3) Method according to any one of claims 1 or 2, characterized in that the small hairless plant material used in steps (a) and (b) is cut stems of pelargonium coated with wax or nutritive agar. 4) Method according to any one of claims 1 to 3, characterized in that step (a) is carried out in a controlled ventilated environment. 5) Method according to any one of claims 1 to 4, characterized in that during step (a), the adults GO are fed by leaving on the hairless plant material of small size of the natural food. 6) Method according to claim 5, characterized in that said natural food is butterfly eggs and, more particularly, eggs of Ephestia kuehniella. 7) Method according to any one of claims 1 to 6, characterized in that step (b) is carried out 24 hours before the start of emergences. 8) Method according to any one of claims 1 to 7, characterized in that the ventilated breeding boxes used in step (b) are placed in air-conditioned rooms. 9) Method according to any one of claims 1 to 8, characterized in that the packaging of the adults Gl in step (e) consists in keeping the adults Gl in a mailing box containing a given support and a plant material . 10) Method according to claim 9, characterized in that food is attached to said plant material. 11) Method according to any one of claims 9 or 10, characterized in that the support given is popcorn kernels. 12) Method according to any one of claims 9 to 11, characterized in that said given support is put in nets. 13) Method according to any one of the preceding claims, characterized in that the entomophagous insects are chosen from predatory bugs belonging to Mirides and Anthocorides and predatory thrips. 14) Method according to any one of the preceding claims, characterized in that the entomophagous insects are Macrolophus caliginosus. 15) Device capable of being implemented in a method according to any one of the preceding claims, characterized in that it comprises a dispatch box containing a given support enclosed in at least one net and a plant material. 16) Device according to claim 15, characterized in that the support given is popcorn kernels.