Blade, propeller and fan diffusing a semiochemical substance, corresponding installation and use

Abstract

The invention relates in particular to a plastic fan blade (11) (V), characterized in that said plastic material is filled throughout with a semiochemical substance or in that a semiochemical substance is impregnated on the surface of the blade (11). Figure 1

Description

Title of the invention: Blade, propeller and fan diffusing a semiochemical substance, corresponding installation and use

[0001] GENERAL TECHNICAL FIELD

[0002] The present invention lies in the general field of pest control.

[0003] PRELIMINARY DEFINITIONS

[0004] Throughout this application, including the claims, the terms below have the following definitions:

[0005] Semiochemical: Chemical signal emitted by living organisms intended to be perceived by other living organisms. These signals are mixtures of generally volatile compounds detected by this species and interpreted as a message triggering a specific behavior (attraction, repulsion, aggregation, trace, etc.). These signals include pheromones, kairomones, allomones or interomones.

[0006] Pheromone: intraspecific semiochemical, that is to say it is produced by individuals of a species to induce reflex behavior in other individuals of the same species. If it is perceived by other species, this signal is interpreted differently (for example, the alarm pheromone of aphids is a food attractant for their predators).

[0007] Mating disruption: a method of controlling insects, mainly lepidoptera, consisting of preventing males from finding females by saturating the detection capacities of males with the attraction pheromone emitted by females. This method is applicable only during insect reproduction periods.

[0008] Trapping: a control method consisting of placing attractive semiochemicals such as sex pheromones, aggregation pheromones, or food attractants in traps. The period of effectiveness of this method depends on the nature of the semiochemical.

[0009] Olfactory barrier: network of volatile semiochemical diffusers causing a flight or avoidance reflex. This system differs from repellents which can have aggressive modes of action such as triggering irritation of the mucous membranes. STATE OF THE ART

[0010] The fight against pests by means of semiochemicals is an increasingly widespread practice, both in agriculture and in manufacturing industries (milling, textiles, hygiene for example).

[0011] The action of semiochemicals is variable. It can be of the attractive type, such as in the case of sexual pheromones, or aggregation or repellent as in the case of alarm pheromones or predator odors.

[0012] For examples of such applications of pheromones, one can usefully refer to the publication: “Communication in insects: a review” Padimi & al J. Exp. Zool. India, Vol. 26, No. 2, 2023, pp 1317-1327.

[0013] Their uses are generally based on diffusion systems such as passive diffusers of very variable appearance (see for example Palagacheva & al. Scientific Papers. Series B, Horticulture. Vol. LXIV, No. 1, 2020, pp 155-162), suspensions of sprayable capsules, or even gels that can be deposited on plant or non-plant supports (for a recent review, see: F. Vogelweith & al. IOBC-WPRS Bulletin Vol 166, 2023, pp 9-17).

[0014] When the control method is based on sexual confusion, these solutions each have their advantages and disadvantages.

[0015] Thus, passive diffusers are effective over long periods, but are installed by hand in large numbers (and often have to be removed by hand at the end of the season). Suspensions of capsules are used in farmers' usual tools but have short-term effectiveness, which requires frequent passages.

[0016] To solve this tedious nature of using semiochemicals in the fields, programmable aerosol bomb systems have been developed.

[0017] Thus, by means of two to four aerosols per hectare positioned at the start of the season once and for all, it is possible to diffuse insect sex pheromones and limit their reproduction in crops (see for example US20080184614, as well as “Sex Pheromone Aerosol Devices for mating disruption: challenges for a brighter future” by Benelli & al. Insects, 2019, 10,308).

[0018] These latter systems also have serious drawbacks because the aerosols atomize significant quantities of pure pheromone droplets which are deposited on the supports surrounding the atomizers and trigger burns on the vegetation, which can lead to the death of the plant.

[0019] Furthermore, the irritant nature of certain pheromones makes it dangerous to pass through fields at the time when these aerosols come into action.

[0020] These atomizers lead to effective crop protection despite the low number of emission points per hectare (only two to four), particularly on large crop areas (greater than 10 hectares).

[0021] The initial propulsion of the pheromone appears to play an essential role in creating a phenomenon of sexual confusion because compared to the use of simple passive diffusers, it would be necessary to count on at least one hundred diffusion points per hectare to achieve the same effect.

[0022] The propulsion of the pheromone creates a pheromone halo on the plant supports, over a distance of the order of five to ten meters from the atomizer. The pheromone thus deposited then spreads from one place to another on the plant supports according to the evaporation and physisorption balances on any type of support such as plants or any type of aerosol present in the culture (dust or water droplets), according to the model described in "How Adsorption of Pheromones on Aerosols Controls Their Transport" L. Jami & al. ACS Central Science 2020 6 (9), 1628-1638.

[0023] It was therefore necessary to find a semiochemical diffusion system allowing, with a reduced number of diffusers, to homogeneously spread a semiochemical in the atmosphere in quantities ranging from 1g to 100g of semiochemical per diffuser, but not inducing side effects on the environment and workers.

[0024] Such diffusers would make it possible to combat lepidoptera by the method of sexual confusion, or against other pests such as rodents, or even roe deer and wild boars by means of repellent semiochemicals.

[0025] The present applicant was therefore interested in identifying systems for the propagation of semiochemicals over long periods by means of ventilated systems.

[0026] A substantial prior art has appeared in particular in the field of aromatherapy or in the field of the fight against certain insects such as mosquitoes.

[0027] However, the dose constraints per diffuser and the notion of protecting a large volume space such as a field, a forest or a hangar cause technical problems which have not been resolved in the prior art.

[0028] Thus in EP1698228, the inventors imagined an individual fan system blowing air onto a cartridge impregnated with a chemical product that repels or kills mosquitoes.

[0029] In this case, the problem is not to protect a large space and blowing through a soaked porous material is enough to spread a product in the immediate environment of the fan. This solution is therefore not suitable for treating fields or forests or large hangars.

[0030] A similar principle of a fan blowing on a support loaded with chemical product is described in US 10378558, but it does not solve the problem of the rapid spread of the chemical product in large spaces. This is also seen in US20060137241 where a fan blows through a stack of balls loaded with insecticide. The air speed after the ball zone is clearly weakened and it can easily be anticipated that the kinetics of establishment of insecticide protection by these objects is slow. This type of system ultimately does not differ much from passive reservoir-type diffusers, since the air speed at the outlet is not very different from that due to the natural mixing of the ambient air.

[0031] In EP1262100, the inventors connected a fan to a mass of material impregnated with an active substance intended to repel insects. In this case, a compartment dedicated to this material must be provided in the fan and the efficiency of the propagation of the active substance depends on the mobility of the active substance in the inert mass.

[0032] It is obvious that the thickness of the inert mass has a detrimental effect on the release efficiency of the active substance, which means that only molecules having saturated vapor pressures greater than a certain value must be considered.

[0033] In US8904701, it is proposed to diffuse carbon dioxide by means of a fan equipped with pellets generating this gas in the presence of humidity, carbon dioxide being a semiochemical of insects such as mosquitoes. Controlling the humidity of the air implies that the air circulated cannot be the ambient air, the humidity of which varies from one moment to another and from one place to another.

[0034] Such a system is unsuitable for a field situation where humidity varies every day or even every hour.

[0035] There therefore remains an unresolved need for means which make it possible, from a reduced number of diffusion points, to cover open or closed spaces with a semiochemical substance quickly and over long periods, without side effects for the environment and the operators, and more particularly without the formation of droplets which cause burns, over a long period and as far as possible on demand, that is to say, adjustable over time. PRESENTATION OF THE INVENTION

[0036] Thus, a first object of the present invention relates to a fan blade made of plastic material, characterized by the fact that said plastic material is loaded at the core with a semiochemical substance or by the fact that a semiochemical substance is impregnated on the surface of the blade.

[0037] Other objects of the invention relate to a propeller equipped with at least one such blade and to a fan equipped with such a propeller.

[0038] Thanks to these characteristics, the fan blades loaded with semiochemical substance make it possible to establish an equilibrium between the material of the blade and the air without passing through a liquid phase which would have carried droplets of semiochemical active.

[0039] The phytotoxic effects of semiochemicals and particularly atomized pheromones are thus avoided.

[0040] This advantage is crucial because the effectiveness of sexual confusion solutions depends on the abundant presence of plant supports to support the emitted pheromone.

[0041] Thus, the invention makes it possible to take maximum advantage of the foliage by installing fans in the heart of the vegetation without causing side effects.

[0042] Semiochemicals can therefore be rapidly dispersed into the atmosphere of fields, forests or buildings to be protected.

[0043] Another advantage of the invention lies in the fact that it accelerates the homogenization of the semiochemical throughout the space to be protected due to the mixing of the air by the fan propeller.

[0044] This mechanical effect makes it possible to reach the necessary concentration of pheromone more quickly in the space to be protected, which makes it possible to significantly reduce the number of diffusers per hectare.

[0045] According to other advantageous and non-limiting characteristics of the blade, taken alone or in any technically compatible combination:

[0046] - said semiochemical substance is chosen from the group consisting of: pheromones, kairomones, allomones and interomones;

[0047] - said plastic material is biodegradable;

[0048] - the biodegradable plastic material is chosen from the group formed by the po biodegradable lyesters, such as polylactide, poly(butyl succinate), polybutylene copolymer (succinate / adipate), polyethers such as natural starch-type sugars, as well as mixtures of at least two of these compounds;

[0049] - a semiochemical substance penetrates into the blade by impregnation via its surface and said plastic material is chosen from the group formed by copolymers such as poly(ethylene, vinyl acetate), block copolymers of the styrene-butadiene, styrene-butadiene-styrene type, optionally hydrogenated, diblock and triblock copolymers of methyl methacrylate and butyl acrylate, as well as mixtures of at least two of these materials;

[0050] - a semiochemical substance is introduced into the heart of the blade by co-injection of said substance, with a plastic material chosen from the group formed by copolymers such as poly (ethylene, vinyl acetate), block copolymers of the styrene-butadiene, styrene-butadiene-styrene type, optionally hydrogenated, diblock and triblock copolymers of methyl methacrylate and butyl acrylate, as well as mixtures of at least two of these materials.

[0051] Advantageously, the propeller comprises 0.5 to 30%, preferably 3 to 15% by weight of semiochemical substance.

[0052] Another object relates to an installation for diffusing a semiochemical substance characterized by the fact that it comprises a plurality of fans conforming to one of the above characteristics, the starting and stopping of which is controlled remotely.

[0053] Advantageously, it includes means for adjusting the rotation speed of the fan propeller on demand.

[0054] Finally, the present invention relates to the use of an installation according to one of the preceding characteristics for the protection of a crop, of a vegetable garden or ornamental, an agricultural plot, a room housing agricultural products, against pests. This particularly concerns insect pests and rodents.

[0055] Advantageously, two to fifty and preferably two to twenty-five fans are used per hectare. DESCRIPTION OF FIGURES

[0056] Other characteristics and advantages of the invention will appear during the description which will now be given, with reference to the appended drawings, which represent, for informational but non-limiting purposes, different possible embodiments.

[0057] In these drawings:

[0058] [Fig. 1] is a front view of a propeller according to the invention;

[0059] [Fig.2] is a back view of the propeller of [Fig.l];

[0060] [Fig.3] is a perspective view of the propeller of Figures 1 and 2;

[0061] [Fig.4] is a view, along a vertical sectional plane, of a manufacturing mold of a such propeller;

[0062] [Fig.5] is a diagram of a fan according to the invention;

[0063] [Fig.6] is a very schematic illustration of a culture equipped with an installation comprising fans according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0064] Aspects of the invention relate to a fan propeller and a fan blade.

[0065] Throughout the present application, the terms "propeller" and "turbine" are considered synonymous.

[0066] Preferably, the propellers are made of a biodegradable or semiochemically rechargeable plastic material.

[0067] Preferably, the propellers or turbines comprise from 2 to 30 blades, preferably from 2 to 20 blades.

[0068] Preferably the propeller weighs between 1 and 500g, preferably between 1 and 250g and, even more preferably, between 1 and 100g, and the rate of semiochemical incorporated in the propeller is between 0.5% and 30% by weight, preferably between 3 and 15% by weight.

[0069] Preferably, the propeller is obtained by injection into a mold.

[0070] Preferably the semiochemical is introduced into the helix:

[0071] - either before injection by preparation of plastic granules containing the se myochemical;

[0072] - either by additivation of the semiochemical directly in the injection process

[0073] - either post injection, by soaking the propeller in a semiochemical solution.

[0074] In the first two cases, the plastic material is loaded at the core with a semiochemical substance, while in the latter case, the semiochemical substance is impregnated on the surface of the propeller blades.

[0075] An example of a biodegradable plastic material that can be used in the context of the present invention is a biodegradable polyester of the polylactide type, poly(butyl succinate), polybutylene(succinate / adipate) copolymer, polyethers such as natural sugars of the starch type. These polymers can be used alone or as a mixture of at least two of them.

[0076] Materials which lend themselves to surface impregnation, which can be repeated, are for example copolymers such as poly(ethylene, vinyl acetate), block copolymers of the styrene-butadiene, styrene-butadiene-styrene type, optionally hydrogenated, diblock and triblock copolymers of methyl methacrylate and butyl acrylate. These polymers can be used alone or as a mixture of at least two of them.

[0077] These plastic materials may contain mineral fillers such as calcium carbonate, clays, talc, carbon black or vegetable fillers such as plant fibers such as flax, hemp, coconut, cotton, or even sawdust such as pine sawdust, and reinforced by additives known to those skilled in the art such as antioxidants, shock absorbers and molding agents.

[0078] The fans are arranged at heights that depend on the application, but are preferably at least 10 centimeters from the ground to avoid absorption of the semiochemical by the ground. Preferably, these diffusers are placed at a height midway between the height of the volume to be treated.

[0079] In the case of agricultural applications, the diffusers will preferably be placed inside the foliage zone (for example the canopy for trees, above the first leaves for seasonal plants).

[0080] The sizing of the fan propeller will preferably be determined according to the pest to be treated and the particularities of the semiochemical.

[0081] One of the particular advantages of the invention is to be able to produce fans sufficiently loaded with semiochemicals to be able to apply significant doses of this substance with a limited number of devices.

[0082] Indeed, depending on the doses of semiochemical required per hectare and a limited number of fans, the quantity of semiochemical loaded into a propeller can for example be up to 40 grams.

[0083] The choice of material therefore depends firstly on its capacity to absorb semiochemicals and then on additional properties such as biodegradability or biosourced nature.

[0084] In Figures 1 to 3 is shown a propeller 1 which can be used in the context of the present invention. In the case shown here, the propeller 1 is formed of a hub 10 and two diametrically opposed blades 11.

[0085] However, it is perfectly possible to envisage that the number of blades 11 is greater than two, as indicated above.

[0086] In the embodiment shown in Figures 1 to 3, the propeller is formed from a single piece.

[0087] However, in an alternative embodiment not shown here, it is possible to envisage that the blades 11 are separate parts from the hub 10. In this case, the blades and hub are manufactured independently of each other, possibly within the same mold. Of course, the hub and the blades will advantageously be provided with complementary connecting means in order to be able to reconstitute a propeller 1. Such means are for example of the tenon / mortise type, elastic snap-fastening, etc.

[0088] The mold shown in [Fig.4] can be used for the manufacture of the propeller 1 according to the invention.

[0089] Conventionally, such a mold 2 comprises two lower 20 and upper 21 shells. 22 is the location of a removable pin and 23 is the injection orifice for the plastic material.

[0090] In particular for the propeller of the aforementioned figures, when the material chosen is polybutylene-co-succinate or polybutylene-co-succinate-co-adipate copolymer, a triblock copolymer of styrene ethylene / butadiene styrene type, or of methylmethacrylate-butyl acrylate-methylmethacrylate type or an ethylene co-vinyl acetate copolymer, it may for example be used in combination with 10% by weight of a pheromone chosen from lepidopteran pheromones, in particular their sexual pheromones, or mammalian pheromones, in particular territory marking pheromones of predators of pests such as deer, rodents or wild boars.

[0091] Additional advantages of the invention lie in the fact that the propeller, in addition to constituting a ventilation system, can be recycled or composted depending on the materials chosen for its manufacture. EXAMPLES

[0092] In the context of the following examples, the biodegradable material used is polybutylene succinate from the company Biochem, reinforced or not with flax fiber manufactured according to patent FR3109859A1.

[0093] As an example of a pheromone-loaded material, the material "Nanostrength M53" from Arkema was chosen. It is an ABA triblock copolymer where the A blocks are made of polymethylmethacrylate and the B block is made of polybutylmethacrylate.

[0094] The injection press used in the examples is of the “HAAKE Minijet Pro” type Piston Injection Molding System”.

[0095] In order to exemplify the principle of the propeller according to the invention, a composite resin mold in accordance with [Fig. 4] was produced to produce propellers whose shape is shown in Figures 1 to 3.

[0096] The pheromones used in the experiment were provided by the company M2i Development.

[0097] Example 1: Manufacture of propellers loaded at the core with eudémis pheromone, by injection-molding using granules pre-impregnated with pheromones and release studies Step 1: Preparation of the granules

[0098] In a rotating powder mixer maintained at a temperature of 30°C, 1.8 kg of polymer granules and 210 g of 95% pure (7,9)-Z,E-dodecadienyl acetate by weight are added. The mixture is stirred for 2 hours, then the impregnated granules are packaged in an aluminum bag equipped with a leak-proof closure system. The polymers tested are: IA: the aforementioned “Nanostrength M53”; IB: PBA (Poly(butyl acrylate)); IC: PBS (Poly(butyl succinate)) loaded with 25% flax fiber. Step 2 Injection of the granules

[0099] The injection takes place as follows: approximately 5 g of granules are introduced into the hopper of a laboratory injection press. The injection chamber is preheated to 140°C and the injection pressure is 20 bars. The molten resin is then injected into an epoxy resin mold produced by 3D printing, as shown in [Fig.4]. Demolding is carried out instantly.

[0100] The propellers are weighed and give the following results:

[0101] Helix IA: 3.63g; Dose of (7,9)-Z,E-dodecadienyl acetate: 360 mg.

[0102] Helix IB: 3.85g; Dose of (7,9)-Z,E-dodecadienyl acetate: 375 mg.

[0103] IC helix: 3.83 g; (7,9)-Z,E-dodecadienyl acetate dose: 385 mg.

[0104] Step 3: Study of pheromone release under standardized conditions at 30°C in a ventilated oven

[0105] Ten helices of each material 1A-C obtained in step 2 are placed in an oven. Every fourteen days, two helices of each material are taken and weighed to evaluate the weight loss corresponding to the loss of pheromone in the oven. The residual pheromone level (in % by weight) is also checked by gas chromatography. The following results are obtained:

[0106] [Tables 1] IA IB IC Days Weight Loss (mg) Residual Pheromone (mg) Weight Loss (mg) Residual Pheromone (mg) Weight Loss (mg) Residual Pheromone (mg) 0 360 375 385 14 102 + / -3 200 125 + / -5 248 120 + / -3 269 28 88 + / -2 105 102+ / -4 151 112+ / -5 148 42 71+ / -5 31 86 + / -3 65 90 + / -4 65 56 21+ / -3 15 34 + / -5 31 31 + / -3 29 70 10 + / -2 5 21 + / -5 11 8+ / -8 12

[0107] Step 4: Study of pheromone release under standardized conditions at 25°C in an air-conditioned room

[0108] Three propellers from each 1A-C series obtained previously are placed on USB fans of the brand “Vanky Coclub”. The propellers are rotated 24 hours a day during the experiment and are weighed every fourteen days to assess the loss of pheromone.

[0109] We obtain the following results:

[0110] [T ables 2] IA IB IC Days Weight loss (mg) Weight loss (mg) Weight loss (mg) 14 185.3 188.3 193.3 28 160 172.0 178.0 42 12 21.6 15.0 56 0 0 0

[0111] We note that: - The propellers according to the invention act as pheromone diffusers over time, regardless of their mobility. - Rotating propellers release the pheromone much faster than resting propellers. - The propellers according to the invention therefore make it possible to manage a more or less uniform diffusion. less strong pheromone since we can modulate their rotation.

[0112] Example 2: Manufacture according to the invention of propellers by co-injection of granules and the pheromone of chilosupresalis (rice borer) and study of their diffusion

[0113] Step 1: manufacturing the propellers loaded with pheromone at the core

[0114] 4.5g of PSB granules loaded with 25% flax fibers and 0.5g of chilosupresalis pheromone, composed of 81% Z11-hexadecenal and 12% Z13-octadecenal and 7% minor compounds, are prepared in the injection chamber. The mixture is melted and injected under pressure at 140°C into the mold of [Fig.4].

[0115] The experiment was repeated twenty times to obtain sufficient samples for the release study. The helices weighed on average 3.83 g and contained on average 310 mg of ZI 1 hexadecenal and 45 mg of ZI3 octadecenal.

[0116] Step 2: Study of the release compared at rest and in rotation

[0117] In an oven at 40°C, on the one hand, five propellers obtained in step 1 are suspended from a support, which allows the entire surface of the propellers to be in contact only with the air. On the other hand, five of these propellers are placed on fan motors and kept rotating continuously 24 hours a day in the same oven. Every fourteen days, two propellers are taken and weighed to assess the weight loss linked to the evaporation of the pheromone, and analyzed by gas chromatography to assess their residual content of each component of the pheromone. The following results are obtained:

[0118] [Tables3] Propellers at rest Propellers in rotation Days Weight loss (mg) Residual pheromone (mg) (hexadecenal / octadecenal) Weight loss (mg) Residual pheromone (mg) (hexadecenal / octadecenal 0 310 / 45 310 / 45 14 38 272 / 43 58 254 / 44 28 35 235 / 46 59 192 / 42 42 36 196 / 45 55 146 / 40 56 34 159 / 43 51 95 / 39 70 32 126 / 45 38 58 / 38

[0119] These examples show that:

[0120] - Propellers manufactured by direct injection of a pheromone and a material plastic are diffusers that retain these pheromones for a long time.

[0121] - The 18-carbon component hardly evaporates when the propeller is at rest. This means that the pheromone bouquet in the air contains almost no of this component. On the other hand, the rotating propellers diffuse the complete pheromone and we can estimate that the action of the propeller is similar to that of the wings of the female lepidopteran which can agitate the air around it to better propagate all the components of the pheromone.

[0122] - The diffusion kinetics of the pheromone is much faster in rotation than at rest, which is all the more interesting since we note that this pheromone is very heavy and therefore has difficulty completely leaving the propeller during a growing season (around 4 months at room temperature). We therefore note that the use of rotating propellers makes it possible to maximize the transfer efficiency of the pheromone into the air.

[0123] Example 3: Surface impregnation of virgin helix with Z / E dodecenyl acetate - release kinetics and reimpregnation for recycling of helices

[0124] Step 1: manufacturing the propellers and impregnating their surface

[0125] In this example, ten pheromone-free propellers are prepared from granules of "M53". Each helix weighs 3.6g. In a 100ml beaker, prepare 50ml of Z / E dodecenyl acetate (85 / 15) and soak each helix for one hour at 30°C. Each helix is ​​then drained, wiped and weighed. The weight of the helices increased to 4.1g on average, an average gain of 500mg (25%) corresponding to the absorption of pheromone.

[0126] Step 2: Study of the release compared at rest and in rotation

[0127] In an oven at 40°C, on the one hand, five propellers obtained in step 1 are suspended from a support. On the other hand, five of these propellers are placed on fan motors and kept rotating continuously 24 hours a day in the same oven. Every fourteen days, two propellers are taken and weighed to assess the weight loss due to pheromone evaporation, and analyzed by gas chromatography to assess their residual content of each pheromone component.

[0128] We obtain the following results:

[0129] [Tables4] Propellers at rest Propellers in rotation Day s Weight loss (mg) Residual pheromone (E / Z8dodecyl acetate) (mg) Weight loss (mg) Residual pheromone (E / Z8dodecyl acetate) (mg) 0 500 500 14 295 208 350 148 28 156 61 145 traces 42 58 traces 0 traces Step 3

[0130] At the end of the experiment, the propellers are again immersed in a beaker containing 50 g of pheromone for 1 hour at 30°C. The average weight of the propellers is then 4.15 g, which shows that these propellers are capable of recharging with pheromone. The diffusion study at rest and in rotation shows similar trends to that obtained in step 2, which validates the possible reuse of these propellers after a first use by re-impregnating the propellers with a pheromone.

[0131] Example 4: Fans loaded with box tree moth pheromone

[0132] The pheromone used is supplied by M2i Development and consists of a 90 / 10 mixture of Z and E 11-hexadecenal at a content of 93% by weight.

[0133] The propellers are manufactured according to the protocol described in example 2, by simultaneously injecting 0.5g of pheromone and 4.5g of “M53” granules into the propeller mold.

[0134] Propellers weighing 3.62g and containing on average 360 ​​mg of pheromone are obtained.

[0135] Example 5: Example of sexual confusion against the box tree moth using a reduced number of fans

[0136] The box tree moth is an invasive pest of ornamental box trees. It reproduces at night in box trees where the females lay their eggs.

[0137] The caterpillars, which appear seven to ten days after laying their eggs, eat the leaves and when the leaves are insufficient, they also eat the bark of the box trees, which ends up killing them.

[0138] The difficulty in establishing sexual confusion with traditional passive diffusers comes from the pheromone which is made up of a 90 / 10 mixture of Z / E hexadecenal, heavy molecules with a short range of action.

[0139] On the other hand, another difficulty is that box trees are often planted in isolated rows, which means that, to ensure a good presence of the pheromone throughout the row, to arrange a large number of passive diffusers (up to one every meter of boxwood).

[0140] We compare the effectiveness of sexual confusion on this butterfly in hedges 10 m long and 80 cm high and 1 m wide between: - on the one hand, a system according to the invention consisting of placing at each end of the hedge two fans equipped with the propellers of example 4 blowing towards the heart of the hedge. The fans are powered by batteries and only operate between 8 p.m. and 6 a.m. - and on the other hand, a commercial confusion system ("Box T Pro Press") requiring ten diffusion points per hedge, each corresponding to 175 mg of pheromone (i.e. 1.75 g per hedge). The product is applied twice (on May 15 and August 11), i.e. a total of 3.5 g of pheromone over the season. - And as a control, isolated untreated box trees at least ten meters from the treated hedges.

[0141] The effectiveness of the treatments is measured by trapping at a rate of one trap per hedge. The traps are loaded with attractants of the brand "Box T Pro Caps" and are renewed after three months. The experiment is set up on May 15 in the Cahors region, in three different gardens spaced at least one kilometer apart.

[0142] The trapping results are as follows:

[0143] [Tables5] Garden 1 Date Witness Commercial System invention 1 / 06 1 0 0 15 / 06 15 1 1 29 / 06 7 0 0 13 / 07 3 0 0 28 / 07 35 4 0 11 / 08 12 2 0 25 / 08 25 0 1 8 / 09 10 0 1 23 / 09 0 0 0

[0144] [Tableauxô] Garden 2 Date Witness Commercial System invention 1 / 06 0 0 0 15 / 06 7 0 0 29 / 06 12 0 0 13 / 07 0 0 28 / 07 16 0 0 11 / 08 6 1 0 25 / 08 10 0 0 8 / 09 0 0 1 23 / 09 0 0 0

[0145] [Tables?] Garden 3 Date Witness Commercial System invention 1 / 06 0 0 0 15 / 06 45 3 0 29 / 06 23 1 1 13 / 07 0 0 0 28 / 07 51 4 1 11 / 08 32 3 0 25 / 08 13 1 2 8 / 09 21 0 1 23 / 09 2 0 0

[0146] Comparison of the system according to the invention with the control shows that sexual confusion is very effective. The performance is as good as with the commercial passive diffuser system, but at a dose ten times lower, which is explained by a better diffusion efficiency of the active ingredient over the season and by the fact that the dose actually emitted is mainly at night, when the males are looking for the females. Example 6

[0147] A homothetic mold with a factor of 400% is printed in epoxy resin and used to manufacture propellers by direct injection of 18 g of “M53” polymer and 4.2 g of pheromone according to a process similar to that of example 2.

[0148] Thirty propellers are thus manufactured, characterized in that they each weigh on average 14.45 g and contain 2.72 g of pheromone each.

[0149] The propellers are attached to USB fans whose power supply is controlled by a timer set to "open" from 8 p.m. to 5 a.m. only (i.e. 9 hours per day). They themselves are connected to solar-rechargeable batteries.

[0150] A plot P of 1.2 hectares (as shown schematically in [Fig.6]) of Malbec vines (located in the commune of Parnac) is equipped with thirty V fans (such as those in [Fig.5]) thus manufactured, distributed according to the prevailing winds VD, so that twenty-five V fans are arranged in the direction of the wind from the vines located on the west side of the plot, and distributed every twelve rows starting from the sixth row of vines to the south, at a rate of five per row with twenty meters of spacing between two fans. Five fans are placed every twenty meters on the last row to the north N and oriented to blow towards the plot. The fans are paused after bud break of the vines, on April 20. The thirty fans represent a pheromone dose of 81g.

[0151] The effectiveness of the fan system in preventing Lobesia reproduction on the plot is demonstrated by comparing the number of Lobesia moths trapped in the treated plot with a control trap located a few hundred meters to the west in a plot protected by conventional insecticides.

[0152] The results are as follows:

[0153] [Tables8] Trapping survey date Chemical witness Plot treated by fans according to the invention May 5, 5 0 June 5, 45 1 July 5, 23 0 August 5, 12 0 September 5, 131 12

[0154] No phytotoxicity is detected.

[0155] It is noted that the network of thirty fans effectively protects the plot against the reproduction of Lobesia.

[0156] Commercial products of the passive diffuser type of the brand “RAK 2 +” of the BASF company are effective at the recommended dose of 500 pheromone diffusers per hectare, diffusing a dose of 135g of pheromone over the season.

[0157] The advantage of the fans according to the invention is therefore to reduce the number of diffusers per hectare and to optimize the dose of pheromone per hectare.

[0158] Furthermore, another advantage of fans is the optimization of the dose and the duration of diffusion of the semiochemical. Indeed, the periods of control against certain pests last between 3 months (for example the tomato leaf miner) and 6 months (for example the codling moth), ensuring that the fans do not need to be changed is a definite advantage and the material from which they are made, soaked in these pheromones, releases the semiochemical very gradually. The release is very slow when the propeller is at rest and much faster when the fan is operating. By adjusting the hours of fan operation to the hours of pest activity, it is possible to optimize the dose of active ingredient necessary to maintain effectiveness against the pest throughout the control period. Example 7

[0159] We repeat the protocol of example 2, but in which the pheromone co-injected into the propellers is a mixture composed by weight as follows: - 10% dimethyl pimelate; - 10% dimethyl aleazate; - 5% methyl caprate; - 20% methyl palmitate; - 54% methyl oleate; - 1% trimethylthiazoline.

[0160] The pheromone is thus injected at a rate of 2% by weight into the composite material. This pheromone is a fox pheromone which very effectively repels rodents such as rats, mice and rabbits.

[0161] The propeller is thus used on a fan in a laundry room usually infested with rats and used to store foodstuffs (flour, pasta, rice, chocolate, etc.). The experiment lasts 2 months. During these 2 months, no rats are trapped in the laundry room. No damage to the food is observed during the period.

Claims

Claims

1. Fan blade (11) (V) made of plastic material, characterized in that said plastic material is filled at the core with a semiochemical substance or in that a semiochemical substance is impregnated on the surface of the blade (11).

2. Blade (11) according to claim 1, characterized in that said semiochemical substance is chosen from the group consisting of pheromones, kairomones, allomones and interomones.

3. Blade (11) according to claim 1 or 2, characterized in that said plastic material is biodegradable.

4. Blade (11) according to claim 3, characterized in that the biodegradable plastic material is chosen from the group formed by biodegradable polyesters, such as polylactide, poly(butyl succinate), polybutylene copolymer (succinate / adipate), polyethers such as natural sugars of the starch type, as well as mixtures of at least two of these compounds.

5. Blade (11) according to one of claims 1 or 2 in which a semiochemical substance penetrates into it by impregnation via its surface, characterized in that said plastic material is chosen from the group formed by copolymers such as poly (ethylene, vi-nylacetate), block copolymers of styrene-butadiene, styrene-butadiene-styrene type, optionally hydrogenated, diblock and triblock copolymers of methyl methacrylate and butyl acrylate, as well as mixtures of at least two of these materials.

6. Blade (11) according to one of claims 1 or 2 in which a semiochemical substance is introduced into the core thereof by co-injection of said substance, with a plastic material chosen from the group formed by copolymers such as poly (ethylene, vinyl acetate), block copolymers of the styrene-butadiene, styrene-butadiene-styrene type, optionally hydrogenated, diblock and triblock copolymers of methyl methacrylate and butyl acrylate, as well as mixtures of at least two of these materials.

7. Propeller (1) of a fan (V) comprising at least two blades (11), characterized in that it comprises at least one blade (11) according to one of the preceding claims.

8. Propeller (1) according to claim 7, characterized in that it comprises 0.5 to 30%, preferably 3 to 15% by weight of se- miochemical.

9. Fan (V), characterized in that it is provided with a propeller (1) according to one of claims 7 or 8.

10. Installation for diffusing semiochemical substances, characterized in that it comprises a plurality of fans (V) in accordance with claim 9, the starting and stopping of which is controlled remotely.

11. Installation according to claim 10, characterized in that it comprises means for adjusting on demand the speed of rotation of the propeller (1) of the fans (V).

12. Use of an installation according to claim 10 or 11 for the protection of a crop, a vegetable or ornamental garden, an agricultural plot, a room housing agricultural products, against pests.

13. Use according to claim 12, wherein said pests are insect pests or rodents.

14. Use according to claim 12, characterized in that two to fifty and preferably two to twenty-five fans (V) are used per hectare.

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