WO2022069695A1

WO2022069695A1 - Packaging device for transporting fly larvae

Info

Publication number: WO2022069695A1
Application number: PCT/EP2021/077070
Authority: WO
Inventors: Ramiro CARCIOCHI; Yoni BOUAZIZ
Original assignee: Nextalim SA
Current assignee: Nextalim SA
Priority date: 2020-10-02
Filing date: 2021-10-01
Publication date: 2022-04-07
Anticipated expiration: 2023-04-02
Also published as: FR3114730A1; FR3114730B1

Abstract

The present invention relates to a device comprising: (i) a container (1) defining an inner space (7) containing larvae (5), notably of the species Hermetia illucens, and opening via an opening (17), (ii) a substrate (4) for feeding the larvae (5), the substrate (4) being moist and at least partially covering the bottom of the container (1), (iii) a barrier covering (6) that is porous to air and at least partially covers the substrate (4), and (iv) a cover (8) at a distance from the barrier covering (6), removably mounted on the container (1), and closing the opening (17), the cover (8) being porous to air and impenetrable to the larvae (5); the inner space (7) containing from 2000 to 6000 larvae (5) per gram of substrate (4), the substrate (4) being arranged between the bottom of the inner space (7) and the barrier covering (6), at least some of the larvae (5) being housed between the barrier covering (6) and the bottom of the container, notably in the substrate (4). The invention also relates to a method for preparing such a device.

Description

Title: PACKAGING DEVICE FOR TRANSPORTING FLY LARVAE

Technical field

The invention relates to a packaging device and to packages suitable for transporting fly larvae, notably Hermetia illucens.

Prior art

The Food and Agriculture Organization of the United Nations anticipates a constant increase in global population to 9 to 10 billion people between now and 2050, necessitating an increase in food production for humans and animals, leading to severe pressure on the environment. This will result in shortages of agricultural land, water, forests, fisheries, biodiversity resources, nutrients and non-renewable energy sources. A substantial lack of proteins is furthermore also expected, with livestock farming struggling to make up for this lack while requiring significant resources, having a negative impact on global warming in particular.

Being very rich in proteins, amino acids, lipids and vitamins, insects are considered to be a credible alternative, even if only for supplying proteins to animals themselves, whether livestock or pets.

Additionally, insects may advantageously be reared using many varied organic waste products. Thus, in the field of bioconversion, it is widely known practice to use fly larvae, such as those of Hermetia illucens, also called black soldier fly, to break organic waste down into compost. In the context of rearing flies on an industrial scale, this industrial-scale bioconversion, which comes within the category of recycling organic waste and advantageously allows the production of compost for resale, will therefore be coupled with the production of fly larvae which will themselves be used to produce derived products, such as flours or oils, for supplementing animal feed.

The past ten years have seen the appearance of an increasing number of companies rearing insects for the purpose of processing organic waste and/or providing derived products such as those mentioned above. There are a number of steps in the development of these flies. Thus, the development of the fly Hermetia illucens, for example, takes place over a number of phases, namely egg, larva, pupa and imago (winged fly).

Whether rearing flies for recycling organic matter or for producing proteins or fats, it is these larvae which are of the greatest interest in that (i) they are the ones capable of breaking down organic foodstuffs given to them (ii) it is at this stage in its development that the fly is richest in products of interest (proteins, fats, amino acids), and is therefore of greatest industrial interest. The fly of Hermetia illucens, for example, has neither mouth nor digestive tract. Moreover, a significant quantity of elements of interest in the larva, or even in the pupa, are used to transform them into the fly and are therefore absent in the latter.

Allowing larvae to develop into flies is therefore only really of interest industrially for reproduction, allowing a new generation of larvae to be produced.

This step in the production of flies for the purpose of producing eggs and therefore new larvae is both technically and financially very burdensome.

Specifically, besides the material and technical means needed to bring about pupation, the reproduction of the flies and the recovery of the eggs, there is:

(i) a loss of yield due to the need to retain some of the larvae, of use in the company's activities, for the generation of adults;

(ii) substantial expenses related to feeding the pupae, keeping them under suitable specific conditions and getting rid of adults once they are no longer needed; and

(iii) a low larval yield due to (a) low rates of conversion of pupae into flies able to reproduce, (b) the fragility of the eggs which have to be handled and are easily damaged and (c) a low rate of eggs eclosing into larvae. Indeed, these steps require advanced technical capabilities specifically adapted to this type of rearing, which are largely still to be fully refined given the very recent emergence of this field.

Thus, many companies seek to remove the steps related to the production of flies to focus only on exploiting the larvae. To that end, they seek to be regularly supplied with young larvae and eggs, 100% of which will be used in bioconversion and/or the production of derived products of interest. Given this growing demand, some companies have in fact decided to specialize in the production of fly eggs and larvae for commercial purposes. Such commercialization therefore entails transporting these larvae from the supplier to the customer. However, there are many problems involved in transporting these larvae.

Specifically, it is important that as many larvae as possible survive between their point of departure and their destination. Besides their survival, these larvae should not have developed much or at all during transport, so as to be able to ensure that the stage of development of the larvae on arrival at the customer corresponds to that expected by them.

It is additionally necessary to ensure that the container in which the larvae are held for transport prevents the larvae from escaping while allowing enough air in for them to breathe. It is also necessary to prevent the ingress of other insects, which might themselves lay eggs and thereby contaminate the container.

There is therefore a need for a packaging device suitable for transporting fly larvae, and notably fly larvae of the species Hermetia illucens, which addresses the issues raised above.

The present invention aims to address these needs.

Summary of the invention

A first subject of the invention is a device comprising:

(i) a container defining an inner space containing larvae, notably of the species Hermetia illucens, and opening via an opening,

(ii) a substrate for feeding the larvae, the substrate being moist and at least partially covering the bottom of the container,

(iii) a barrier covering that is porous to air and at least partially covers the substrate, and

(iv) a cover at a distance from the barrier covering, removably mounted on the container, and closing the opening, the cover being porous to air and impenetrable to the larvae; the inner space containing from 2000 to 6000 larvae per gram of substrate, the substrate being arranged between the bottom of the inner space and the barrier covering, at least some of the larvae being housed between the barrier covering and the bottom of the container, notably in the substrate.

The device according to the invention advantageously makes it possible to transport a substantial quantity of fly larvae, in particular larvae of the species Hermetia illucens. Specifically, the inventors have determined that via this device, and by virtue notably of the ratio of the quantity of larvae to unit mass of the substrate stated above, the larvae may be transported over a number of days:

- while very substantially limiting the decrease in the number of live and functional larvae between the time when they are added to the container and the end of transport several days later. In other words, the number of healthy individuals stays substantially the same throughout transport of the larvae.

- while limiting their progression to a later, less desirable stage in their development, by virtue of sufficient but limited availability of nutritional elements, resulting from the abovementioned ratio of the quantity of larvae to unit mass of the substrate.

The device also advantageously makes it possible to limit the risk of contamination of the content of the container by insects, insect eggs and/or larvae other than those placed in the container, and notably other than larvae of Hermetia illucens.

The moist substrate may comprise more than 60% of its mass as water, and notably comprises between 65 and 85% of its mass as water, preferably between 70 and 75% of its mass as water.

The substrate may be chosen from the group consisting of brewers' grains, such as notably barley grains; wheat bran; maize bran; rice bran; or mixtures thereof.

In particular, the substrate may have a thickness of at least 2 cm, and notably a thickness of between 2 cm and 10 cm, notably of between 2 cm and 6 cm, in particular of between 2 cm and 5 cm, more particularly of between 2 cm and 4 cm.

The barrier covering may comprise wood sawdust and/or wheat bran and less than 25% of its mass as water, and notably between 5% and 20% of its mass as water, preferably between 10 and 15% of its mass as water. More particularly, the barrier covering may have a thickness of between 0.1 cm and 5 cm, notably of between 0.2 cm and 2 cm, in particular of between 0.5 cm and 1.5 cm, more particularly of between 0.5 cm and 1.2 cm. The barrier covering may in particular have a thickness of less than 1 cm.

The distance between the barrier covering and the cover, measured along the x-axis of the container, may notably be greater than 3 cm, in particular greater than 4 cm, and is notably between 4 cm and 8 cm, in particular between 4 cm and 6 cm and more particularly between 4 cm and 5 cm. What is meant by "distance between the barrier covering and the cover" is the shortest distance separating them.

The container comprises at least one wall defining the inner space. Notably, it may comprise a bottom wall, on top of which the substrate and the barrier covering are placed, and from which at least one side wall extends.

The device may comprise a layer of talc which covers at least part of the wall of the container, notably at least part of the side wall of the container. The device may in particular be characterized in that the inner space comprises a layer of talc which covers at least part of the side wall of the container that is at a distance from the substrate and/or from the barrier covering.

The cover may comprise a screen made of a fibrous material, for example a woven fabric, for example a gauze; or a non-woven fabric, for example a felt; or a tulle, and may in particular comprise a screen made of woven fibrous material or a tulle. The screen may notably be made of tulle.

In particular, more than 95%, or even more than 99%, of the volume of the portion of the inner space defined between the barrier covering and the cover of the device may be filled with air, in particular with air at room temperature and ambient pressure.

Another subject of the present invention relates to a method for preparing a device according to the invention, characterized in that it comprises:

- a first step of introducing the substrate into the inner space of the container;

- a second step of placing larvae, in particular of the species Hermetia illucens, on the substrate introduced into the container in the first step; - a third step of introducing the barrier covering into the container, this third step being in particular carried out at least five minutes after carrying out the second step; and

- a fourth step of closing the opening of the container with the cover.

Other features and advantages of the invention will become further apparent from reading the following non-limiting description and from examining the figure which is described below.

[Fig 1] schematically shows a cross section through one exemplary embodiment of a device according to the invention.

In the drawing, the proportions of the constituent elements are not necessarily shown to scale for greater clarity.

Definitions

The "inner surface" delimits the inner space of the container. It includes the inner face of the bottom wall, the inner face of the side wall and the inner face of the junction region of the container which are all oriented towards the inner space.

The adjectives "lower" and "upper", "inner" and "outer", "horizontal" and "vertical" refer to orientations or to positions in the service position.

The "service position" of a device according to the invention is the position in which the bottom of the container is placed flat on a surface.

What is meant by "horizontal" and "vertical" is an orientation forming, with a perfectly horizontal and vertical plane, respectively, an angle smaller than 20°, preferably smaller than 15°, preferably smaller than 10°, preferably smaller than 5°, or even smaller than 2°, or even smaller than 1°. A "junction region" connects two faces and is strictly concave, viewed from inside the container. A junction region may in particular connect two planar faces of different orientations, such as the bottom face and side face of the container as described herein.

"Include", "define", "have" or "comprise" should be interpreted in a broad and non-limiting manner.

What is meant by a " substrate for feeding the larvae" is a composition containing nutrients for the growth of the larvae, i.e. comprising sources of proteins, of lipids, of carbohydrates and of fibres, and water, in such quantity and of such quality suitable for feeding the larvae. Illustrations of such substrates particularly suitable for the invention are described elsewhere in the present text.

What is meant by an element that is "porous to air" is, both for the barrier covering and for the cover, an element that allows air to flow freely, as opposed to airtight.

What is meant by "impenetrable to the larvae" is a cover provided with a plurality of apertures passing all the way therethrough and allowing air to pass through, the aperture of largest diameter from among the plurality of apertures having a diameter that is not large enough for a larva to be able to pass through the cover via the aperture.

Detailed description

Figure 1 shows one exemplary conditioning device according to the invention. This device is preferably intended for the transport of fly larvae 5 of the species Hermetia illucens, but the invention is not limited to this fly.

Container

The device comprises a container 1 of axis X defining an inner space 7, and opening via an opening 17.

More particularly, the container 1 comprises a bottom wall 3 and at least one side wall 2 extending from the bottom wall 3 up to the opening 17. The side wall 2 and bottom wall 3 of a container 1 according to the invention are solid. The bottom wall 3 has an inner face 15 that is oriented towards the inner space 7 of the container, is preferably substantially planar and that, in the service position, preferably extends horizontally.

The side wall 2 has an inner face 14 of the inner side wall that is oriented towards the inner space and that extends, preferably substantially perpendicularly to the inner face 15 of the bottom wall 3, up to an upper edge 18.

The bottom wall 3 and side wall 2 also define a junction region 16 between the inner face 14 of the side wall 2 and the inner face 15 of the bottom wall 3. The junction region 16 preferably provides a gradual transition between the inner face 14 of the side wall 2 and the inner face 15 of the bottom wall 3.

The lower face of the container 1 is thus formed of the inner face 15 of the bottom wall 3, of the inner face 14 of the side wall 2 and of the junction region 16.

In one particularly advantageous embodiment, the inner face 15 of the bottom wall 3 is continuously planar, i.e. it extends in a plane without interruption up to the junction region 16 with the inner face 14 of the side wall 2.

No depression, for example in the form of a slot, of a groove, of a cavity, or of a hole, whether or not passing all the way therethrough, is therefore made in the inner face 15 of the bottom wall 3. No protrusion, for example in the form of a bulge of material or of a boss, projects from the inner face 15 of the bottom wall 3. In other words, any straight line traced over the inner face 15 of the bottom wall 3 connects two points of the outer contour of the inner face 15 of the bottom wall 3 without being interrupted by a depression or a protrusion.

In particular, neither the bottom wall 3 nor the side wall 2 of a container 1 of the invention comprises any through-apertures.

The container 1 may take a general frustoconical shape. The bottom wall 3 may widen from the bottom towards the opening 17 or vice versa. Conversely, the side wall 2 of the container 1 may be straight, i.e. extend along an axis perpendicular to the inner face 15 of the bottom wall 3.

The side wall 2 of the container 1 may have a cross section transverse to the axis X that is generally circular, polygonal, notably square or rectangular, or oval, in shape. Preferably, the side wall 2 consists of a plurality of substantially planar faces, preferably more than three faces and/or fewer than 10 faces, preferably fewer than six faces, preferably four faces. The angle formed between two adjacent faces is preferably constant whichever the pair of faces in question. The faces of the side wall 2 may all be of the same length.

Preferably, the side wall 2 has a plurality of planar faces defining a cross-sectional profile (i.e. in a plane perpendicular to the axis X) that is polygonal, preferably rectangular.

The container 1 may be made of a material chosen from a wood, a metal, a plastic, a glass, a polymer, notably a thermoplastic such as polypropylene, or mixtures thereof, provided that the container 1 is sealtight with respect to gases and to liquids.

The container 1 may vary in size, i.e. the inner space 7 may has a volume varying from 400 cm³ to 2000 cm³, in particular from 400 cm³ to 1200 cm³, more particularly from 400 cm³ to 900 cm³, notably from 500 cm³ to 800 cm³, and in particular between 600 cm³ and 750 cm³. For example, the volume of the inner space 7 may be about 400 cm³, about 450 cm³, about 500 cm³, about 550 cm³, about 600 cm³, about 650 cm³, about 700 cm³, about 750 cm³, about 800 cm³, about 850 cm³ or about 900 cm³. Preferably, the inner space 7 has a volume of about 750 cm³.

The height of the inner face 14 of the side wall 2, i.e. the distance separating the inner face 15 of the bottom wall 3 and the opening 17, measured along the axis X, is between 5 and 12 cm, in particular between 6.5 cm and 10 cm.

By way of illustration, the container 1 may have an inner space 7 of which the volume is 450 cm³, the inner face 14 of the side wall 2 having a height of 5.4 cm. Also by way of illustration, the container 1 may have an inner space 7 of which the volume is 750 cm³, the inner face 14 of the side wall 2 having a height of 6.8 cm.

Additionally, the container may be transparent or translucent. As a variant, it may be opaque.

A "transparent", "translucent" or "opaque" body is so with respect to light in the visible range.

The inner face 15 of the bottom wall 3 and at least part of the inner face 14 of the side wall 2 may be opaque. In particular, the segment of the side wall 2 that extends from the bottom wall 3 up to the height at which the barrier covering 6 is arranged (19) may be opaque. Preferably, the segment of the side wall that extends between the cover and the height at which the barrier covering is arranged is transparent. Since the larvae 5 are photophobic, this promotes their burrowing into the substrate 4 and/or into the barrier covering 6. Climbing of the larvae 5 up the side wall 2 towards the cover 8 is thus limited, thereby limiting the risk of larvae 5 escaping from the device.

The inner space 7 of the container may comprise a layer of talc 12 which at least partially covers the inner face 14 of the side wall 2 that is at a distance from the substrate 4 and/or from the barrier covering 6.

At least the segment 20 of the side wall 2 that extends between the barrier covering 6 and the cover 8 may be covered with the layer of talc 12. In particular, the entirety of the inner surface may be covered with talc 12.

Specifically, the talc has the advantageous and unexpected property of significantly decreasing the number of larvae 5 that move over the side wall 2 coated therewith, which thereby makes it possible to limit the climbing of the larvae 5 up the side wall 2 towards the cover 8, and thus limit the risk of larvae 5 escaping from the device.

Substrate

The device comprises, in the inner space 7 of the container 1, a substrate 4 for feeding the larvae 5.

This substrate 4 is notably characterized by the fact that it is moist.

What is meant by moist is that its water mass represents more than 60% of the mass of the substrate, notably between 65 and 85% of the mass of the substrate, preferably between 70 and 75% of the mass of the substrate.

The substrate 4 may in particular take the form of a loose material, and notably of a granular material.

The substrate 4 is in particular not fermented.

The substrate 4 may be chosen from the group consisting of brewers' grains, such as notably barley grains; wheat bran; maize bran; rice bran; or mixtures thereof.

What is meant by barley grain is the residual solids recovered after filtering the wort on completion of the process of saccharification of the barley or of a mixture of grains in which barley is the major constituent. In particular, the barley grain forming the substrate 4 is not fermented.

What is meant by wheat bran is the entity formed of the tough outer envelope of the wheat grain, separated from the cleaned and brushed wheat in the typical process of milling commercial flour.

What is meant by maize bran is the entity formed of the outer envelope of the maize grain, free, or mostly free, of the starchy part or germ.

What is meant by rice bran is the entity formed of the pericarp, or bran, and of the germ of the rice, and comprises only unavoidable amounts of fragments of husk, crushed or broken rice grains, or distillery rice and calcium carbonate resulting from the normal milling of edible rice.

Such a substrate 4 has a texture and aeration that advantageously facilitates the burrowing of the fly larvae 5, which thereby allows:

- them to be given access to all of the nutritional elements, and to the water, present in this substrate 4;

- the number of individuals that survive during transport thereof to be increased; and

- the number of larvae 5 that move over the side wall 2 to be decreased, which thereby makes it possible to limit the climbing of the larvae 5 up the side wall 2 towards the cover 8, and thus limit the risk of larvae 5 escaping from the device.

Such a substrate 4 may advantageously consist of a medium that is nutritional for the larvae 5 comprising:

- from 2 to 15% by weight, in particular from 3 to 8% by weight of crude protein, in relation to the total weight of the substrate 4;

- from 5 to 25% by weight, in particular from 5 to 18% by weight, and more particularly from 8 to 13% by weight of fibre, in relation to the total weight of the substrate 4; and

- from 70 to 85% by weight of water, in particular from 75 to 85% by weight of water, in relation to the total weight of the substrate 4; and optionally: - from 0.5 to 5% by weight, in particular from 0.5 to 2% by weight of crude fat, in relation to the total weight of the substrate 4;

- from 0.5 to 8% by weight, notably from 0.5 % to 5% by weight, in particular from 0.5 to 2% by weight of carbohydrates, in relation to the total weight of the substrate 4; and/or

- from 0.5 to 5% by weight, in particular from 0.5 to 2% by weight of ash, in relation to the total weight of the substrate 4.

The substrate 4 may at least partially, preferably totally, cover the bottom of the inner space 7 of the container 1 and be in contact with the bottom wall 3 and in contact with the side wall 2.

The substrate 4 may have a thickness of at least 2 cm, and notably a thickness of between 2 cm and 10 cm, notably of between 2 cm and 6 cm, in particular of between 2 cm and 5 cm, more particularly of between 2 cm and 4 cm.

A thickness of at least 2 cm is preferable in order to afford the possibility, to all of the larvae 5 present in the container 1, to be able to burrow into the substrate and thus have access to all of the nutrients present in the substrate, and to the water contained therein.

Conversely, an overly deep substrate in relation to the number of larvae 5 placed in the container 1 would constitute an overly large amount of matter in relation to the needs of the larvae and would thus be an economic loss through wastage of this substrate.

Lastly, the substrate 4 of a device according to the invention is also characterized in that it is arranged between the bottom of the inner space 7 and the barrier covering 6.

Barrier covering

The device comprises a barrier covering 6 that at least partially covers the substrate 4. Specifically, it is arranged between the substrate 4 and the cover 8.

The barrier covering 6 limits the ability of the larvae 5, placed on the substrate 4, to move up the side wall 2 in the direction of the opening 17 and also prompts the larvae to burrow into the substrate 4. Specifically, because of its low water content, the barrier covering 6 dries the larvae 5 out, which were previously in contact with the moist substrate 4, which will make it much more difficult for them to move up the side wall 2 in the direction of the opening 17. Additionally, since the larvae 5 prefer moist environments, they will be encouraged to remain in contact with the substrate 4, in particular buried in the substrate 4.

This is because specifically, the barrier covering 6, being porous to air, is in particular dry.

What is meant by dry is in particular that the barrier covering 6 comprises in particular less than 25% of its mass as water, notably less than 20%, and more particularly less than 15% of its mass as water.

The barrier covering 6 may in particular take the form of a loose material, and notably of a granular material.

The barrier covering 6 may be chosen from the group consisting of wood sawdust and wheat bran.

In particular, a barrier covering 6 of the present invention may comprise:

- wood sawdust and/or wheat bran; and

- less than 25% of its mass as water, notably less than 20% of its mass as water, and more particularly less than 15% of its mass as water.

The barrier covering 6 may completely cover the substrate 4, and more particularly completely cover the substrate 4 uniformly.

The barrier covering 6 is advantageously in contact with the side wall 2 of the container 1 of the invention.

The barrier covering 6 may have a thickness of between 0.2 and 2 cm, in particular of between 0.5 and 1.5 cm, more particularly of between 0.5 and 1.2 cm, in the device according to the invention.

Fly larvae

The larvae 5 are in particular of the species Hermetia illucens.

The device comprises a content by mass of larvae of between 2000 and 6000 larvae 5 per gram of substrate 4, in particular between 3000 and 5000 larvae 5 par gram of substrate 4. Thus, the device may advantageously comprise at least 50 000 larvae, in particular at least 100 000 larvae 5, notably between 100 000 and 5 000000 larvae 5, and more particularly between 100 000 and 1 000 000 larvae 5.

This ratio of the quantity of larvae to unit mass of the substrate ensures:

- the high survival rate of larvae 5 during transport in view of the quantity of nutrients and water available per larva 5;

- and at the same time makes it possible to limit the quantity of nutrients and water so as to greatly limit the development of the larva 5 over the time of their transport, which may range from a few hours, or a day, to several days, and more particularly from one or two days to a week.

Preferably, at least some of the larvae 5 are housed between the barrier covering 6 and the bottom of the container 1, notably in the substrate 4. Of course, since the larvae 5 are live, mobile organisms, they will move around within the container, mainly within the substrate 4 which has a texture suitable for their burrowing.

At least one of the larvae 5 will eclose or have eclosed after at most 36 hours. The larvae 5 may therefore have eclosed one hour before being placed in the container 1, two hours, three hours, four hours, five hours, six hours, 12 hours, 18 hours, 24 hours, 30 hours, 36 hours before being placed in the container 1. In particular, the larvae 5 will have eclosed at most 18 hours before being placed in the container 1.

Cover

The device according to the invention is also characterized in that it comprises a cover 8 that is removably mounted on the container. This cover 8 is suitable for closing the opening of the container 1.

The cover 8, at a distance from the barrier covering 6, is also characterized in that it is porous to air and impenetrable to the larvae 5. It may comprise or consist of a grating, mesh or weave of which the mesh or weave is sized to prevent a larva 5 from passing therethrough. Thus, the assembly formed by the container 1 and the cover 8 according to the invention, when the cover 8 closes the opening 17 of the container, is impenetrable to the larvae 5.

The cover 8 is removably attached to the side wall 2, preferably to an upper edge 18 of the side wall 2, for example by means of a self-gripping strip, of Velcro® type, the first and second parts of which are bonded to the upper edge 18 of the container 1 and to the periphery of the cover 8, respectively. The cover 8 is then very fast to attach and detach while securely closing the device during transport. Additionally, a continuous self-gripping strip effectively prevents the larvae 5 from getting out of the device.

According to one embodiment, a cover 8 may comprise a screen 10 made of a fibrous material, for example a woven fabric, for example a gauze, or a non-woven fabric, for example a felt, and may in particular comprise a screen 10 made of woven fibrous material. It may also be a flexible grating, of the type used to make mosquito screens. A screen 10 may be made of tulle.

The screen 10 may completely cover the opening 17 and be fixed, for example bonded, such as thermobonded, to the upper edge 18 of the container 1.

As a variant, the cover 8 may comprise a rigid part 9 that is attached, removably, for example screwed or slotted onto the upper edge 18 of the container 1 , the rigid part 9 comprising a void passing all the through its thickness, the screen 10 being placed over the void, the screen 10 being in particular attached to the rigid part 9. The void in the rigid part 9 must of course be dimensioned sufficiently so that a satisfactory exchange of air can take place between the inside of the container 1 and the outside. What is meant here by satisfactory is enough for this factor not to negatively affect the survival of the larvae 5 present in the container 1, for example due to a lack of oxygen.

The distance between the barrier covering 6 and the cover 8, measured along the x-axis of the container 1, may in particular be greater than 3 cm, in particular greater than 4 cm, and is notably between 4 and 8 cm, in particular between 4 and 6 cm and more particularly between 4 and 5 cm.

Preferably, more than 95%, or even more than 99%, of the volume of the portion of the compartment defined between the covering and the cover 8 is filled with air, in particular by air at room temperature (i.e. between 15°C and 30°C, in particular between 20°C and 27°C, notably between 22°C and 27°C). Preparing a device of the invention

The present invention also relates to a method for preparing a device according to the invention, comprising:

- a first step of introducing the substrate 4 into the inner space 7 of the container 1 ;

- a second step of placing larvae 5 of the species Hermetia illucens, on the substrate 4 introduced into the container 1 in the first step;

- a third step of introducing the barrier covering 6 into the container 1, this third step being in particular carried out at least five minutes after carrying out the second step; and

- a fourth step of closing the opening 17 of the container 1 with the cover 8.

The substrate 4 may be introduced into the container 1 manually or in an automated manner. The same applies, independently, for each of the steps of this method.

The method may comprise an additional step of applying a layer of talc 12 over some or all of the inner surface of the container 1.

This step of applying a layer of talc 12 over the inner surface of the container 1 may take place:

- before the step of introducing the substrate 4 into the inner space 7 of the container 1 ;

- between the step of introducing the substrate 4 into the inner space 7 of the container 1 and the step of placing larvae 5 of the species Hermetia illucens on the substrate 4;

- between the step of placing larvae 5 of the species Hermetia illucens on the substrate 4 and the step of introducing the barrier covering 6 into the container 1; and/or

- between the step of introducing the barrier covering 6 into the container 1 and the step of closing the opening 17 of the container 1 with the cover 8.

For example, when the layer of talc 12 is applied to the entirety of the inner surface of the container 1, this step of applying the layer of talc takes place before the step of introducing the substrate 4 into the inner space 7 of the container 1.

For example, when only the segment 20 of the side wall 2 extending between the barrier covering 6 and the cover 8 is covered with a layer of talc, this step of applying the layer of talc may take place at any time in the method prior to closing the opening 17 with the cover 8, for example between the step of introducing the barrier covering 6 into the container 1 and the step of closing the opening 17 of the container 1 with the cover 8, or before the step of introducing the substrate 4 into the inner space 7 of the container 1. The step of closing the opening 17 of the container 1 with the cover 8 may for example consist of a step of thermobonding a screen 10 to an upper edge 18 of the side wall 2 of the container 1.

Of course, the invention is not limited to the examples and embodiments described by way of illustration.

Claims

1. Device comprising:

(i) a container (1) defining an inner space (7) containing larvae (5), notably of the species Hermetia illucens, and opening via an opening (17),

(ii) a substrate (4) for feeding the larvae (5), the substrate (4) being moist and at least partially covering the bottom of the container (1),

(iii) a barrier covering (6) that is porous to air and at least partially covers the substrate (4), and

(iv) a cover (8) at a distance from the barrier covering (6), removably mounted on the container (1), and closing the opening (17), the cover (8) being porous to air and impenetrable to the larvae (5); the inner space (7) containing from 2000 to 6000 larvae (5) per gram of substrate (4), the substrate (4) being arranged between the bottom of the inner space (7) and the barrier covering (6), at least some of the larvae (5) being housed between the barrier covering (6) and the bottom of the container, notably in the substrate (4).

2. Device according to Claim 1, in which the substrate (4) comprises more than 60% of its mass as water, and notably comprises between 65 and 85% of its mass as water, preferably between 70 and 75% of its mass as water.

3. Device according to Claim 1 or 2, in which the substrate (4) is chosen from the group consisting of brewers' grains, such as notably barley grains; wheat bran; maize bran; rice bran; or mixtures thereof.

4. Device according to any one of the preceding claims, in which the substrate (4) has a thickness of at least 2 cm, and notably a thickness of between 2 cm and 10 cm, notably of between 2 cm and 6 cm, in particular of between 2 and 5 cm, more particularly of between 2 and 4 cm.

5. Device according to any one of the preceding claims, in which the barrier covering (6) comprises:

- wood sawdust and/or wheat bran; and

- less than 25% of its mass as water, and notably between 5% and 20% of its mass as water, preferably between 10 % and 15% of its mass as water.

6. Device according to any one of the preceding claims, in which the barrier covering (6) has a thickness of between 0.1 cm and 5 cm, notably of between 0.2 cm and 2 cm, in particular of between 0.5 cm and 1.5 cm, more particularly of between 0.5 and 1.2 cm.

7. Device according to any one of the preceding claims, in which the distance between the barrier covering (6) and the cover (8), measured along the x-axis of the container (1), is greater than 3 cm, in particular greater than 4 cm, and is notably between 4 cm and 8 cm, in particular between 4 cm and 6 cm and more particularly between 4 cm and 5 cm.

8. Device according to any one of the preceding claims, characterized in that the inner space (7) comprises a layer of talc (12) which covers at least part of a side wall (2) of the container (1), in particular at least part of the side wall (2) that is at a distance from the substrate (4) and/or from the barrier covering (6).

9. Device according to any one of the preceding claims, in which the cover (8) comprises a screen (10) made of a fibrous material, for example a woven fabric, for example a gauze; or a non-woven fabric, for example a felt; or a tulle, and in particular comprises a screen made of woven fibrous material or a tulle.

10. Device according to any one of the preceding claims, in which more than 95%, or even more than 99%, of the volume of the portion (20) of the inner space (7) defined between the barrier covering (6) and the cover (8) is filled with air, in particular with air at room temperature and ambient pressure.

11. Method for preparing a device as defined in any one of Claims 1 to 10, characterized in that it comprises:

- a first step of introducing the substrate (4) into the inner space (7) of the container (1);

- a second step of placing larvae (5), in particular of the species Hermetia illucens, on the substrate (4) introduced into the container (1) in the first step;

- a third step of introducing the barrier covering (6) into the container (1), this third step being in particular carried out at least five minutes after carrying out the second step; and

- a fourth step of closing the opening (17) of the container (1) with the cover (8).