WO2023194695A1

WO2023194695A1 - Biological method for controlling biting insects

Info

Publication number: WO2023194695A1
Application number: PCT/FR2023/050508
Authority: WO
Inventors: Olivier Guerret; Yannick ESCUDIE
Original assignee: Melchior Material And Life Science France
Priority date: 2022-04-07
Filing date: 2023-04-07
Publication date: 2023-10-12
Also published as: FR3134285A1

Abstract

The present invention relates to a method for controlling biting insects, such as aphids, which comprises applying, onto plants to be treated, microcapsules containing one or more attractive substances which have an attractive effect on predators of said biting insects. The microcapsules can be used in combination with an asphyxiant and/or desiccant insecticide. The present invention also relates to a composition comprising an asphyxiant and/or desiccant insecticide and microcapsules containing one or more attractive substances which have an attractive effect on predators of said biting insects, and to the method for preparing same.

Description

DESCRIPTION

Title: BIOLOGICAL PROCESS FOR FIGHTING STINGING INSECTS

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a method for combating biting insects such as aphids using microcapsules containing one or more attractant substances which have an attractive effect on predators of said biting insects. The microcapsules can be used in combination with an asphyxiating and/or drying insecticide. The present invention therefore also relates to a composition comprising microcapsules containing one or more attractant substances and an asphyxiating and/or drying insecticide, and its preparation process.

STATE OF THE ART

Aphids are biting insects causing great damage to crops due to injuries inflicted on plants but also to diseases of which they can be vectors. Furthermore, aphids are capable of reproducing by mating and parthenogenesis, which makes them very prolific.

The first method of control is to use molecular, synthetic insecticides such as products based on cypermethrin, lambda-cyhalothrin or deltamethrin, or natural such as products based on pyrethrum for example. These molecules act by poisoning aphids according to various biochemical mechanisms. These products are very effective but by acting on a large scale on very large colonies of aphids, a selection of individuals less sensitive or even resistant to these insecticides takes place naturally. The selection of aphids induces a rapid and invasive spread of these resistant strains. Faced with this adaptability of aphids to chemical insecticide molecules, those skilled in the art had to gradually increase the doses or frequency of treatments applied, which had the effect of further improving the selection of resistant strains to ultimately lead to a situation where the insecticide becomes ineffective. The public authorities therefore reacted by forcing users to alternate insecticides to limit the effects of selection, but this tactic only delays the development of resistance.

Furthermore, the increase in doses and the use of increasingly toxic molecules for aphids cannot be done without sometimes serious consequences for the biodiversity and sometimes even for humans. The increasing difficulty of reconciling the effectiveness of chemical insecticides and respect for health and the environment is clearly described in: Report from the National Center of Expertise on Vectors, 2014. Use of insecticides and resistance management.

A second method of control with insecticides exists and consists of using fatty or surface-active substances such as paraffins, vegetable oils or soaps. These products sprayed on plants attacked by aphids have an asphyxiating (for paraffins) and drying (for soaps or surfactants) effect on the insects they submerge. These products are therefore very effective when aphids are affected by spraying but as many colonies protect themselves by wrapping leaves around them, one passage is never sufficient and the proliferation of aphid populations from hidden foci in the vegetation involves numerous passages, which leads to significant costs. The doses used are also very high (with approximately 15 to 30 g per ha per application), the risk of soil and runoff pollution is significant in the long term. Such products are described in particular in EP3442333.

A third method of biological control consisted of releasing aphid predators such as aphidivorous ladybugs, lacewings and hoverflies. These insects in the form of larvae or adults are capable of overcoming aphid colonies but their effect is delayed in relation to the invasion of aphids since enough aphids are needed for their predators to develop sufficiently to have a cleansing effect of a culture. Depending on climatic effects, the release of predators may have to be repeated several times and the farmer cannot know whether the ladybugs or lacewings will stay in his fields or prefer to go to neighboring areas richer in aphids such as wooded areas. . If in the long term the artificial repopulation of an area by aphid predators can improve the health situation of a plot, the logistical constraints for organizing these releases and the low certainty of their effectiveness on the year's yield do not. do not provide an economically sustainable solution. Furthermore, if because of other infestations the farmer is forced to use an insecticide, he will impact this reintroduced insect population and lose his protection against aphids. There is therefore a need to find solutions for combating biting insects, such as aphids, offering a better lasting footprint than chemical insecticides, longer-lasting effectiveness than asphyxiating and/or drying insecticides and greater effectiveness than artificial releases of predators. Furthermore, the artificial side of these releases requires the introduction of foreign species into ecosystems, which can have unpredictable destabilizing effects.

Large-scale crop protection methods are mainly implemented by spraying. Capsule suspensions suitable for these application methods must have particles less than 20 micrometers. The semiochemical encapsulation methods of the prior art are not satisfactory due to the viscosity of the suspensions and the particle sizes obtained which lead to the clogging of the spraying means. This viscosity is notably linked to the size of the particles for encapsulation. It is therefore necessary to find a solution that is easy to implement, that is to say easily sprayable.

The applicant has therefore found a way to use predators present in the ecosystem to effectively combat aphids, while optimizing application costs.

SUMMARY OF THE INVENTION

This means consists of the use of suspensions of microcapsules containing one or more substances naturally emitted by biting insects, such as aphids, or plants attacked by said biting insects, such as aphids, having an attractive effect on predators of these stinging insects, such as aphidivorous ladybugs, lacewings or hoverflies. These microcapsules therefore have the effect of attracting these predators to the plot to clean the centers of biting insects, such as aphids, and possibly to prevent the arrival of new centers of biting insects, such as aphids.

Thus, the subject of the present invention is a method of combating biting insects comprising the application to plants to be treated of microcapsules containing one or more attractant substances which have an attractive effect on predators of said biting insects. Advantageously, the method will also include the application to the plants to be treated of an asphyxiating and/or drying insecticide, preferably simultaneously with the application of the microcapsules. More particularly, the method will include the application, in particular spraying, to the plants to be treated of a mixture comprising an asphyxiating and/or drying insecticide and said microcapsules.

The present invention therefore also relates to a composition comprising said asphyxiating and/or drying insecticide and said microcapsules.

According to a first embodiment, the composition comprises from 1% to 3%, preferably from 2% to 3% by weight of the asphyxiating and/or drying insecticide, and from 0.01 to 0.1%, preferably from 0.02% to 0.05% by weight of the microcapsules, and is useful as a slurry in a method according to the invention.

According to a second embodiment, the composition comprises from 30% to 99%, preferably from 60% to 99% by weight of the asphyxiating and/or drying insecticide, and from 0.1% to 4%, preferably of 0.6% to 2% by weight of the microcapsules, and is useful as a concentrated premix intended to be diluted before use to form the slurry useful in a method according to the invention.

Such a composition may also comprise a surfactant, an anti-foaming agent, one or more additives, advantageously chosen from anti-microbial agents, anti-oxidant agents and mixtures thereof.

The present invention also relates to a process for preparing a composition according to the invention comprising the addition of a suspension of microcapsules to the asphyxiating and/or drying insecticide, optionally mixed with the surfactant, the anti-foaming agent. , and the additives, when present, advantageously at a temperature of 15°C to 30°C, preferably 18°C to 25°C.

DETAILED DESCRIPTION OF THE INVENTION

Method

The present invention therefore relates to a method for combating biting insects comprising the application to plants to be treated of microcapsules containing one or more attractant substances which have an attractive effect on predators of said biting insects.

This method can be used to treat plants such as beets; fruit trees such as apple trees, pear trees, peach trees, or plum trees; cereals such as wheat or barley; market garden plants such as beans, artichokes, carrots, potatoes, beans, or peas, etc.

By “biting insect” also called biting-sucking insect or sucking insect, we mean, within the meaning of the present invention, an insect which feeds on the sap of plants, by biting these plants, then sucking the sap. These are more particularly aphids and/or mealybugs, preferably aphids.

By “attractant substance” is meant, within the meaning of the present invention, one or more substances which have an attractive effect on predators of biting insects, such substances being naturally emitted by biting insects or plants attacked by said biting insects. . Predators of biting insects, such as aphids, are more particularly aphidiphagous insects such as braconid insects, coccinellids (ladybugs), syrphids, anthocorids, chrysopids or a combination of these. Preferably these are ladybugs, especially 7-spotted or 11-spotted, lacewings, hoverflies or a combination of these.

The attractant substance(s) will be more particularly p-farnesene (e.g. E-p-farnesene) alone or in mixture with one or more substances chosen from camphene, salicylic esters (in particular alkyl esters having from 1 to 6 carbon atoms) such as methyl salicylate, E-2-hexenal, Z-3-hexenyl acetate, 2-phenyl ethanol, p-ocimene, benzyl alcohol, and a combination thereof, the mixture advantageously containing at least 50% by weight of p-farnesene. These molecules are identified attractants of aphid predators (see Han & al. J. Agric. Food Chem. 2002, 50, 2571). This could in particular be p-farnesene (e.g. E-p-famesene) alone or mixed with camphene, the mixture advantageously containing at least 50% by weight of p-farnesene.

Advantageously, the method according to the invention will also include the application to the plants to be treated of an asphyxiating and/or drying insecticide, preferably simultaneously with the application of the microcapsules. More particularly, the method will include the application, in particular spraying, to the plants to be treated of a mixture comprising an asphyxiating and/or drying insecticide and said microcapsules. The porridge may contain, in relation to the total weight of the porridge, 1% at 3%, preferably from 2% to 3% by weight of the asphyxiating and/or drying insecticide, and from 0.01 to 0.1%, preferably from 0.02% to 0.05% by weight of the microcapsules.

Microcapsules

The microcapsules used in the method according to the invention advantageously have a median diameter D50 ranging from 0.5 pm to 20 pm, preferably from 0.8 pm to 10 pm.

By “median diameter D50” of microcapsules is meant, within the meaning of the present invention, the median diameter of a distribution of microcapsules, that is to say the diameter such that 50% of the microcapsules by volume have a smaller diameter or equal to this value and that 50% of the microcapsules by volume have a diameter greater than this value. It is measured by laser diffraction, in particular using a Mastersizer 3000 device, in particular according to the method described in the experimental part.

Preferably, the microcapsules according to the invention comprise a core containing the attractant substance(s), this core being surrounded by a solid outer envelope. Advantageously, the microcapsules comprise:

- a core comprising a mixture of wax, vegetable oil and the attractant substance(s).

- an outer envelope surrounding the core comprising a HASE type copolymer, optionally neutralized, totally or partially, in the form of a sodium, potassium or ammonium salt,

According to another embodiment, the microcapsules comprise:

- a core comprising a mixture of a fatty substance having a melting point ranging from 25°C to 75°C, preferably ranging from 25°C to 70°C, more preferably from 25°C to 65°C (for example from 30°C to 60°C), and the attractant substance(s).

- an outer envelope surrounding the core comprising a HASE type copolymer, optionally neutralized, totally or partially, in the form of a sodium, potassium or ammonium salt.

Heart of microcapsules

The core of the microcapsules advantageously represents 99.8% to 95% by weight of the total weight of the microcapsules. The heart comprises the attractive substance(s), advantageously mixed with a wax and an oil.

Preferably, the core comprises, in particular is constituted by, a mixture of wax, oil, the attractant substance(s), and one or more additives, preferably chosen from an anti-UV additive, a antioxidant and a mixture thereof.

The heart will advantageously contain, in relation to the weight of the heart:

— from 5% to 30% by weight of wax,

— from 60% to 90% by weight of vegetable oil, and

— from 1% to 20% by weight of the attractant substance(s).

In addition, the heart may contain 0% to 7% additives.

According to an alternative embodiment, the core comprises, in particular is constituted by, a mixture of a fatty substance, the attractant substance(s), and one or more additives, preferably chosen from an anti- UV, an antioxidant and a mixture thereof, the fatty substance having a melting point ranging from 25°C to 75°C, preferably ranging from 25°C to 70°C, more preferably from 25°C to 65°C °C (for example from 30°C to 60°C).

According to this same embodiment, the heart will advantageously contain, in relation to the weight of the heart:

— from 60% to 90% by weight of a fatty substance having a melting point ranging from 25°C to 75°C, preferably ranging from 25°C to 70°C, more preferably from 25°C to 65°C C (for example from 30°C to 60°C), and

— from 1% to 20% by weight of the attractant substance(s).

In addition, the core may contain from 0% to 7% by weight of one or more additives.

By “wax” is meant, for the purposes of the present invention, a compound that is lipophilic and solid at room temperature (approximately 25°C) and atmospheric pressure (1013.25 hPa), preferably of natural origin. Preferably, the wax has a melting temperature above 45°C at atmospheric pressure.

The waxes capable of being used in a composition according to the invention can be chosen from waxes of animal origin, waxes of plant origin, mineral waxes, synthetic waxes and their mixtures. As wax of animal origin, we can cite beeswax, lanolin wax, or even Chinese insect wax. As wax of plant origin, we can cite rice wax, carnauba wax, candelilla wax, jojoba wax, ouricurry wax, esparto wax, cork fiber wax, sugar cane wax, Japanese wax, or even sumac wax. As mineral wax, we can cite montan wax, microcrystalline waxes, paraffins, or even ozokerite. As synthetic wax, we can cite polyethylene waxes, waxes obtained by the Fisher-Tropsch synthesis, or even waxy copolymers and their esters. The hydrogenated derivatives of the waxes mentioned above can also be used as wax in the context of the present invention. We can also cite waxes obtained by catalytic hydrogenation of oils of animal or vegetable origin having unsaturated fatty chains, linear or branched, in C8-C32. Among these, we can in particular cite hydrogenated jojoba oil, hydrogenated sunflower oil, hydrogenated castor oil, hydrogenated coconut oil, or even hydrogenated lanolin oil, as well as tetrastearate of di-(trimethylol-1,1,1-propane). It is also possible to use waxes obtained by transesterification and hydrogenation of oils of vegetable origin, such as castor or olive oil, such as the waxes sold under the names Phytowax ricin 16L64®, Phytowax ricin 22L73® and Phytowax Olive 18L57® by the company SOPHIM.

Advantageously, the wax is chosen from the group consisting of beeswax, lanolin wax, Chinese insect wax, rice wax, carnauba wax, candelilla wax, jojoba wax, ouricurry wax, esparto wax, cork fiber wax, sugar cane wax, Japanese wax, sumac wax, montan wax, microcrystalline waxes, and mixtures thereof.

By “oil” is meant, within the meaning of the present invention, a fatty compound, liquid at room temperature and atmospheric pressure, immiscible with water and non-volatile.

The oil according to the invention will be a vegetable oil advantageously chosen from the group consisting of sunflower oil, peanut oil, soybean oil, rapeseed oil, corn oil, olive oil, grape oil, walnut oil, flaxseed oil, palm oil, coconut oil, argan oil, avocado oil, almond oil, hazelnut oil, pistachio oil, rice oil, cottonseed oil, wheat germ oil, sesame oil, and mixtures thereof. The oil of animal origin will advantageously be chosen from the group consisting of cod liver oil, shark oil and their mixtures. Fatty substances having a melting point ranging from 25°C to 75°C, preferably ranging from 25°C to 70°C, more preferably from 25°C to 65°C (for example from 30°C to 60°C C), capable of being used in a composition according to the invention can be chosen from hydrogenated or non-hydrogenated coconut oil, beeswax, lanolin wax, solid paraffin, and mixtures thereof.

One or more additives may also be present in the core of the microcapsules, preferably chosen from an anti-UV additive, an antioxidant and a mixture of these.

Anti-UV additives or antioxidants well known to those skilled in the art can be added to limit the oxidation reactions caused by oxygen on the surface of the particles such as tert-butylhydroxytoluene (BHT), tert-butylhydroxyanisole (BHA), tocopherol, oxybenzone, octabenzone, derivatives of the benzotriazole family (such as 2-(2 ^, -hydroxy-3',5 ^, -tertamylphenyl)benzotriazole, or 2-(2 '-hydroxy-3'-tert-butyl-5'-methyl-phenyl)-5-chlorobenzotriazole), propyl gallate, or derivatives of 4-tetramethyl-piperidine, notably known under the name HALS ("hindered amine light stabilizers” in English, or hindered amine photo-stabilizers) and described in Schaller, C., Rogez, D. & Braig, A. “Hindered amine light stabilizers in pigmented coatings. » J Coat Technol Res 6, 81-88 (2009), and its nitroxides (obtained by oxidation of HALS as indicated in FR2788272).

The outer shell of the microcapsules will advantageously represent 0.2% to 5% by weight of the total weight of the microcapsules.

The envelope will advantageously comprise a copolymer of the HASE type, optionally neutralized, totally or partially, in the form of a sodium, potassium or ammonium salt.

By “HASE type copolymer” (HASE being the abbreviation of “Hydrophobically modified Alkali Swellable Emulsion”, namely an emulsion capable of swelling in an alkaline medium modified in a hydrophobic manner), is meant, within the meaning of the present invention, a copolymer of (meth)acrylic acid (eg methacrylic acid), alkyl acrylate (eg ethyl acrylate) and one or more hydrophobic macromonomers of formula Chem. I following: [Chem. I]

in which :

- m is an integer greater than or equal to 5, in particular between 10 and 40, preferably between 10 and 30, and

- R a hydrocarbon group of formula C _n H2n+i in which n is an integer between 9 and 25, preferably between 10 and 22 and even more preferably equal to 12, 16 or 22. The group R is therefore hydrophobic.

By “neutralized, totally or partially”, is meant, within the meaning of the present invention, that all or part of the carboxylic acid functions (COOH) carried by the HASE type copolymer is in salt form, and more particularly in sodium, potassium or ammonium salt form.

Advantageously, the HASE type copolymer comprises, in particular consists of, relative to the total weight of the copolymer:

- between 30% and 40% by weight of repeating units from methacrylic acid,

- between 45% and 60% by weight of repeating units from ethyl acrylate, and

- between 5% and 20% by weight of repeating units from a macromonomer of formula Chem. I following:

[Chem. I]

in which :

■ m is an integer greater than or equal to 5, in particular between 10 and 40, preferably between 10 and 30, and

■ R a hydrocarbon group of formula C _n H2n+i in which n is an integer between 9 and 25, preferably between 10 and 22 and even more preferably equal to 12.

The HASE type copolymer can be prepared for example according to one of the methods described in WO2011/104599, WO201 1/104600 and EP1778797. This may be Pharma 38 or Viscoatex 730LV from the Coatex company. The microcapsules according to the invention may be presented more particularly in the form of a suspension. The suspension of microcapsules may contain from 10% to 50%, preferably from 20% to 40% by weight of microcapsules, relative to the total weight of the suspension.

Such a suspension can be prepared according to the procedures described in US2018/0064102.

Thus, the microcapsules can be prepared by a process comprising the following steps:

(a) the preparation of a fatty phase comprising:

- wax and vegetable oil or the fatty substance resulting from their mixture, or the fatty substance having a melting point ranging from 25°C to 75°C, preferably ranging from 25°C to 70°C, more preferably from 25°C to 65°C (for example from 30°C to 60°C),

- the attractant substance(s), and

- optionally one or more additives, the fatty phase having a temperature higher than the melting temperature of the wax or the fatty substance,

(b) the preparation of an aqueous solution comprising the HASE type copolymer, the aqueous solution having a pH greater than or equal to 7.6, in particular greater than or equal to 8, in particular from 8 to 10, and a substantially identical temperature to that of the fatty phase,

(c) adding the fatty phase to the aqueous solution comprising the HASE type copolymer, and stirring so as to form a dispersion of fatty phase droplets in the aqueous solution, and

(d) acidification to a pH of 6 to 7.5, preferably 6.5 to 7.2.

Step (a)

The fatty phase is prepared in step (a) so as to obtain a mixture of wax/oil or fatty substance, attractant substance(s), and possibly one or more additives having the composition of the heart described above.

The fatty phase is maintained, preferably with stirring, at a temperature higher than the melting temperature of the wax so as to be liquid. In a particular embodiment, the fatty phase is at a temperature of 50°C to 85°C, in particular 60°C to 80°C. Advantageously, the fatty phase is prepared by mixing the oil and the additive(s) which is heated to a temperature higher than the melting temperature of the wax, then adding the wax, then adding the attractant substance(s).

Step (b)

The aqueous solution of step (b) may be prepared by basifying an aqueous solution comprising the HASE type copolymer by adding a base, so as to obtain a pH greater than or equal to 7.6 (e.g. 7 .6 to 10), in particular greater than or equal to 8, in particular from 8 to 10. This base will advantageously be chosen from sodium or potassium carbonate, ammonium hydroxide or ammonia in aqueous solution, sodium hydroxide, potassium hydroxide and combinations thereof.

Advantageously, the aqueous solution comprises from 0.1% to 10%, in particular from 0.1% to 5%, preferably from 0.1% to 1%, by weight of the HASE type copolymer relative to the weight of the aqueous solution. The concentration of HASE type copolymer in the aqueous solution makes it possible to influence the size of the final microcapsules. Indeed, the size of the final microcapsules decreases when the concentration of HASE type copolymer increases.

This aqueous solution is then heated to a temperature substantially identical to that of the fatty phase.

By “substantially identical temperature” to that of the fatty phase, we advantageously mean a temperature not varying by more than 10°C, in particular by more than 5°C, relative to the temperature of step (a). Preferably, the temperature of step (b) will be identical to that of step (a).

Thus, the aqueous solution is advantageously at a temperature of 50°C to 85°C, in particular 60°C to 80°C.

Step (c)

In this step, the fatty phase having the temperature of step (a) is added to the aqueous solution having the temperature of step (b).

The mixture is then stirred so as to form a dispersion of fatty phase droplets in the aqueous solution. The fatty phase droplets formed in the aqueous solution will form the core of the microcapsules. Acidification makes it possible to precipitate the HASE type copolymer present in the aqueous solution on the droplets which then become microcapsules comprising the core based on the fatty phase surrounded by the solid envelope based on the HASE type copolymer. These particles are dispersed in water and thus form an aqueous suspension of the microcapsules.

In a particular embodiment, the acidification is carried out by adding an acid such as hydrochloric acid, phosphoric acid, sulfuric acid, an organic acid of the carboxylic acid type (particularly acetic acid or propionic acid) or a mixture of these, in particular phosphoric acid, until reaching a pH of 6 to 7.5, preferably 6.5 to 7.2. This acid is preferably added in the form of an aqueous solution.

The temperature of the aqueous suspension of the microcapsules thus obtained is then advantageously brought to a temperature below the melting point of the wax, in particular at a temperature between 20°C and 30°C.

Asphyxiating and/or drying insecticide

By “asphyxiating and/or drying insecticide” is meant, within the meaning of the present invention, a liquid substance which asphyxiates and/or dries the stinging insect when this substance coats the stinging insect, in particular when the stinging insect is covered by said substance.

The asphyxiating and/or drying insecticide may more particularly be a paraffin, a vegetable oil, a silicone oil, a soap, in particular synthetic or natural, or a combination of these, advantageously a paraffin, a soap, in particular synthetic or natural, or a combination thereof, preferably paraffin.

The paraffin may more particularly be a liquid paraffin having a pour point lower than -5°C, in particular measured according to the ASTM D97 standard.

The vegetable oil may be as defined above.

The soap could be black soap.

The asphyxiating and/or drying insecticide may be presented more particularly in the form of an emulsion, for example mixed with a surfactant and/or an antifoaming agent. The surfactant will preferably be chosen from nonionic surfactants such as polyalkoxylated fatty acids, fatty acid and sorbitan esters, (poly)alkoxylated fatty acid and sorbitan esters, alkoxylated alkylphenols, alkoxylated fatty alcohols. , esters of fatty acids and glycerol and combinations thereof.

The antifoam agent may be chosen from organosiloxanes and their polymeric forms, organosilicones, polyethers and polyesters of glycerides and combinations thereof.

Composition

The composition according to the invention comprises said asphyxiating and/or drying insecticide and said microcapsules comprising the attractant substance(s).

The asphyxiating and/or drying insecticide and the microcapsules comprising the attractant substance(s) are in particular as defined above.

Preferably, the composition comprises from 1 to 3 parts, preferably from 2 to 3 parts by weight of the asphyxiating and/or drying insecticide, and from 0.01 to 0.1 parts, preferably from 0.02 to 0. .05 parts by weight of the microcapsules.

According to a second embodiment, the composition comprises from 30% to 99%, preferably from 60% to 99% by weight of the asphyxiating and/or drying insecticide, and from 0.1% to 4%, preferably of 0.6% to 2% by weight of the microcapsules, and is useful as a concentrated premix intended to be diluted before use to form the slurry.

The composition according to the invention may also contain a surfactant (to form an emulsion) and/or an anti-foaming agent (to prevent the formation of foam during the preparation of the emulsion). The surfactant and the antifoaming agent are in particular as defined above.

The composition could thus include:

- from 30 to 99 parts, preferably from 60 to 99 parts by weight of the asphyxiating and/or drying insecticide,

- from 0 to 30 parts, preferably from 5 to 20 parts by weight of a surfactant, - from 0.1 to 4 parts, preferably from 0.6 to 2 parts by weight of the microcapsules containing the attractant substance(s), and

- from 0 to 1 parts, preferably from 0.1 to 1 parts by weight of an anti-foaming agent. When it is in the form of a concentrated premix, the composition will advantageously comprise, relative to the total weight of the composition:

- from 30% to 99%, preferably from 60% to 99% by weight of the asphyxiating and/or drying insecticide,

- from 0% to 30%, preferably from 5% to 20% by weight of a surfactant,

- from 0.4% to 4%, preferably from 0.6% to 2% by weight of the microcapsules containing the attractant substance(s), and

- from 0% to 1%, preferably from 0.1% to 1% by weight of an anti-foaming agent.

The composition may also include additives making it possible to improve the stability of the mixture from a microbiological point of view or from the point of view of resistance to oxidation stimulated by UV radiation. Thus, the composition will advantageously comprise one or more additives, advantageously chosen from antimicrobial agents, antioxidant agents and mixtures thereof, such additives being well known to those skilled in the art. This or these additives may be present in an amount of 0.1 to 2 parts by weight (e.g. in an amount of 0.1% to 2% by weight in the premix).

The anti-microbial agent may be chosen from hydrogen peroxide, peracetic acid, perpropionic acid, products from the isothiazole family.

The antioxidant agent may be chosen from butyl-hydroxytoluene, tocopherol, and oxybenzone.

The composition according to the invention is in particular in the form of an inverse emulsion.

Such a composition can be prepared by a process comprising the addition of a suspension of the microcapsules to the asphyxiating and/or drying insecticide, optionally mixed with the surfactant, the antifoaming agent, and the additives, when they are present. , advantageously at a temperature of 15°C to 30°C, preferably 18°C to 25°C.

Thus, when the composition comprises a surfactant, an anti-foaming agent, and/or one or more additives, the preparation process advantageously comprises: - the mixture of the asphyxiating and/or drying insecticide, the possible surfactant, the possible anti-foaming agent, and the possible additives, preferably at a temperature of 15°C to 30°C, preferably of 18°C to 25°C, then

- the addition of a suspension of microcapsules.

FIGURES

[Fig. 1]: Image of the microcapsules of example 2 obtained using an optical microscope with a x640 zoom.

[Fig. 2]: Image of the premix of example 4 obtained using an optical microscope with a x640 zoom.

EXAMPLES

E-p-farnesene, other attractants, polyethylene glycol monooleate and antioxidants such as BHT or tocopherol are sourced from Sigma Aldrich.

The HASE type copolymer used in the examples is Pharma 38 supplied by the company Coatex.

The sunflower oil used in the examples is a commercial Isio 4 sunflower oil.

Bleached beeswax is supplied by the Prayon company.

The antifoam agent is supplied by DOW (DC62) or BYK (BYK-1630).

The viscosities are measured using a Brookfield DV1 viscometer equipped with a chamber.

The size of the microcapsules is measured by light diffraction analysis with a Mastersizer 3000 apparatus by diffraction of a laser beam. The measurement protocol is as follows:

The samples are first prepared by dispersing 0.5 g of formulation in 100 ml of demineralized water with magnetic stirring for 10 min. Then we proceed to measure the particle sizes, first taking care to align the device and measure the background noise to record the diffraction phenomena generated by the water. The sample is then introduced into the measuring cell and 5 successive measurements are carried out. The particle size is then determined by taking the average of these 5 measurements. The analysis of the contents of attractant substances is carried out by gas chromatography (CPG) with a flame ionization detector on an Agilent - HP series II 5890 device.

Studies on the release of attractant substances are carried out in ventilated ovens without windows so as not to be exposed to light radiation. These studies are carried out using two methods, either by monitoring the weight loss of the samples, or by monitoring the residual concentration of the pheromone in the sample by CPG. Optical microscopy is carried out on a ZEISS brand AXIO PLAN 2 microscope. Observations of the samples are carried out in transmission with a 40x plane and 20x plane objective. A ZEISS brand AxioCam ICC3 camera allows images to be viewed on a computer screen.

Example 1: Manufacturing a suspension of E-p-farnesene microcapsules

Demineralized water 126g and HASE type copolymer 15g are introduced into a three-necked flask No. 1 fitted with anchor-type mechanical stirring. The mixture is stirred for 5 min (100 rpm) and the pH is adjusted to 11 with a 10% sodium hydroxide solution. In a three-necked flask No. 2, the following are stirred at 70°C: vegetable oil (coconut oil) 71.8 g, E-p-farnesene 13.7 g, a-tocopherol 1.3 g, BHT 1.3 g, and oxybenzone 1.3g. The contents of three-necked flask No. 2 are poured onto the contents of three-necked flask No. 1 with stirring (600 rpm) at a temperature of 70°C. Three-necked flask No. 1 is then left stirring (600 rpm) 1 hour after the end of the addition. The pH is then adjusted to 7.5 by adding 4% H3PO4. The mixture is cooled to a temperature of 20°C. 0.2g of 35% H2O2 are then added with stirring (300 rpm) followed by a sufficient quantity of demineralized water of 5g.

The suspension of microcapsules obtained has a viscosity of 101,000 cP at 3 rpm and 20° C. (Brookfield DV1 viscometer with LV5 mobile) and a median diameter D50 of 1.9 m.

The release of E-p-farnesene is studied by placing 2g of the suspension in an oven at 30°C on a plastic support weighing 0.2g and regularly weighing the sample. Under these conditions, the half-life characteristic of the diffusion of E-p-farnesene at 30°C is 13 days.

Example 2: Preparation of microcapsules of a mixture of attractant substances for ladybugs and lacewings (50/50 Ep-farnesene/camphene) Into a three-necked flask No. 1 fitted with anchor-type mechanical stirring, 135 g of demineralized water and 8.7 g of HASE-type copolymer are introduced. The mixture is stirred for 5 min (100 rpm) and the pH is adjusted to 10 with a 10% sodium hydroxide solution. In a three-necked flask No. 2, the following are stirred at 70°C: vegetable oil (sunflower oil) 64g, beeswax 7.13g, Ep-farnesene 6.8g, camphene 6.8g, a -tocopherol 0.5g, BHT 0.5g, and oxybenzone 0.5g. The contents of three-necked flask No. 2 are poured onto the contents of three-necked flask No. 1 with vigorous stirring (600 rpm) at a temperature of 70°C. Three-necked flask No. 1 is then left stirring (600 rpm) 1 hour after the end of the addition. The pH is then adjusted to 7.5 by adding 4% H3PO4. The mixture is cooled to a temperature of 20°C. 0.2g of 35% H2O2 are then added with stirring (300 rpm) followed by a sufficient quantity of demineralized water of 12g.

The suspension of microcapsules obtained has a viscosity of 800 cP at 20°C, 6 rpm (Brookfield DV1 viscometer with SC4-16 mobile) and a median diameter D50 of 10.6 pim. The microcapsules were observed under an optical microscope with a x640 zoom. The image obtained is presented in Figure 1.

Example 3: Use of microcapsules to attract beneficial insects - demonstration by trapping

0.5 g of a suspension of microcapsules according to example 1 or 2 is deposited on a glued plate type trap measuring 20cmx20cm, yellow in color. The attractant substance begins to release approximately 24 hours after installation, once the water in the composition has evaporated.

We have in a mixed orchard garden (apple trees, peach trees, plum trees, cherry trees) and vegetable garden (beans, potatoes, artichokes) located in the town of Pern in the Lot (France), measuring 30mx30m, on supports located 1 m at 1.5m from the ground, 5 glued plates measuring 20cmx20cm with the suspension of microcapsules from Example 1, 5 lacquers with the suspension of microcapsules from Example 2 and 5 plates which are blank and will serve as a control population. The glued plates are distributed in such a way that they are spaced 5 m apart, taking care to be at least 5 m from the edge of the garden. Every week we carry out a survey of the traps and count the number of insects trapped by identifying their nature. We report the number of ladybugs, lacewings and the rest of the trapped insects (flies, hymenoptera, lepidoptera, etc.) is grouped into a single count. The experience period is from May 1 to May 31. The results obtained are presented in Table 1 below.

[Table 1]

This example shows that the traps equipped with the microcapsule suspensions of Example 1 or Example 2 attract ladybugs and lacewings more than the control. The appearance of the first black aphids was observed on April 28 on beans and on May 3 on cherry trees. The appearance of green aphids on peach trees and woolly aphids on apple and pear trees was observed on May 18.

Example 4: Manufacturing a concentrated premix on a Unimix 15L unit with a constant dose (2%) of microcapsules

In a first phase, the reactor is loaded with Isane Biolife 78 paraffin oil (10.00 kg) and polyethylene glycol monooleate (800 g) and the mixture is stirred at a speed of 1200 rpm for 5 min at a temperature of 25 °C.

A second phase consists of adding the antifoam agent DC62 (0.03kg) or BYK-1630 (0.04kg). The medium is stirred at a speed of 1000 rpm for 8 min at 25°C.

A third phase consists of the addition of the suspension of microcapsules (606g) prepared according to Example 2. The suspension is added via the recirculation pump operating at 1200 rpm and the mixture is left to homogenize for 5 min at 30°C.

Recovery: the product is recovered in the form of a white liquid inverse emulsion with a viscosity of 1200cp at 3 rpm and 20°C (Brookfield DV1 viscometer with LV5 mobile).

The emulsion is analyzed by optical microscopy with a zoom of x640 which demonstrates the integrity of the capsules. The image obtained is presented in Figure 2. Example 5: Manufacturing a concentrated premix on a Unimix 15L unit at a constant dose (4%) of capsules

The operating conditions of Example 4 are reproduced with the following quantities: Isane Biolife 78 paraffin oil (8.00 kg), polyethylene glycol monooleate (640 g), antifoam agent BYK-1630 (0.04 kg), suspension of microcapsules (970g) prepared according to Example 2.

Recovery: the product is recovered in the form of a white liquid inverse emulsion with a viscosity of 1500cp at 3 rpm and 20°C (Brookfield DV1 viscometer with LV5 mobile).

Example 6: Preparation of a spray mixture

We aim for dilutions of 20L/ha or 20L in 1000L of water (volume sprayed on 1 ha). In a 15L mixer, 8.5L of water are added and 0.15L of the premix from Example 4 is poured in with stirring. A paraffin emulsion with microparticles in suspension is obtained.

The resulting slurry is sprayed onto a support and observed by optical microscopy.

Example 7: Preparation of microcapsules of a mixture of aphid repellent and attractants for ladybugs and lacewings (50/50 E-P-farnesene/methyl salicylate)

Demineralized water (1075 g) and the acrylic encapsulating agent Pharma38 from the company Arkema (70 g) are introduced into a three-necked flask No. 1, fitted with an anchor-type mechanical stirrer. The mixture is stirred for 5 min (100 rpm), then the pH is adjusted to 10 with a 10% sodium hydroxide solution. In a second three-necked flask No. 2, the following are stirred at 70°C: vegetable oil (sunflower oil, 513 g), beeswax (57 g), E- -farnesene (55 g), salicylate methyl (55 g), a-tocopherol (10 g), BHT (10 g) and oxybenzone (10 g). The mixture from three-necked flask No. 2 is poured into three-necked flask No. 1 with vigorous stirring (600 rpm) at a temperature of 70°C. Three-necked flask No. 1 is then left stirring (600 rpm) for 1 hour after the end of the addition. The pH is then adjusted to 7.5 by adding 4% H3PO4. The mixture is cooled to a temperature of 20°C. A quantity of 0.3 g of H2O2 at 35% w/w is then added with stirring (300 rpm) followed by a sufficient quantity of demineralized water of 64 g. The suspension of microcapsules No. 1 thus obtained has a viscosity of 1,800 cP at 20° C., 6 rpm (Brookfield Viscometer, mobile SC4-16) and median diameter of D50s = 14.5 pm.

Example 8: Preparation of microcapsules of a mixture of attractants for ladybugs and lacewings (50/50 b-farnesene/Methyl Salicylate)

Demineralized water (1075 g) and the acrylic encapsulating agent Pharma38 from the company Arkema (70 g) are introduced into a three-necked flask No. 1, fitted with an anchor-type mechanical stirrer. The mixture is stirred for 5 min (100 rpm), then the pH is adjusted to 10 with a 10% sodium hydroxide solution. In a second three-necked flask No. 2, the following are stirred at 70°C: the vegetable oil (sunflower oil, 387 g), the beeswax (43 g), the E-P-farnesene (110 g), the salicylate of methyl (110 g), a-tocopherol (20 g), BHT (20 g) and oxybenzone (20 g). The mixture from three-necked flask No. 2 is poured into three-necked flask No. 1 with vigorous stirring (600 rpm) at a temperature of 70°C. Three-necked flask No. 1 is then left stirring (600 rpm) for 1 hour after the end of the addition. The pH is then adjusted to 7.5 by adding 4% H3PO4. The mixture is cooled to a temperature of 20°C. A quantity of 0.3 g of H2O2 at 35% w/w is then added with stirring (300 rpm) followed by a sufficient quantity of demineralized water of 64 g.

The suspension of microcapsules No. 2 thus obtained has a viscosity of 1,260 cP at 20° C., 6 rpm (Brookfield Viscometer, mobile SC4-16) and a median diameter D50 of 13.4 pm.

Example 9: Production of a sprayable mixture composed of mineral oil and microcapsules.

The mixtures are prepared directly in a portable spray application device (wheelbarrow type) associated with a carbon bar (e.g. ESCARRPULV200Z from Zeppelin).

The slurries consist of dissolving the different mixtures/products to be tested in water, the total quantity of which is calculated for an application volume of 300 L/ha. Mixture A: Self-emulsifying mineral oil (1500 mL) Oviphyt® from the company De Sangosse dissolved with stirring in 28.5 L of water under the conditions provided by the manufacturer.

Porridge B (according to i

Suspension of microcapsules No. 1 from Example 7 (100 mL) and Oviphyt® self-emulsifying mineral oil (1500 mL) mixed with stirring in 28.4 L of water under the conditions provided by the manufacturer of the self-emulsifying mineral oil From Sangosse.

Porridge C (according to i

Suspension of microcapsules No. 2 from Example 2 (100 mL) and Oviphyt® self-emulsifying mineral oil (1500 mL) mixed with stirring in 28.4 L of water under the conditions provided by the manufacturer of the mineral oil self-emulsifying Sangosse.

Example 10: Use of mixtures A, B and C to control aphids on seed beet plots in comparison with an untreated control (TNT) and an insecticide reference product (Flonicamide (50 WG)) applied at 140g/ Ha.

The test plots are located in Beauce, France.

Each method is applied on a square plot of 100m ² surrounded by a cultivation strip 25 m wide, to avoid any interaction with the rest of the plot. Each modality is repeated 3 times.

The mixtures A, B and C are applied by spraying under the standard conditions of use of mineral oil as provided by the manufacturer, every 9 to 10 days depending on the weather, i.e. at TO, T+10 days , and T+19 d.

Flonicamide (50 WG) is used as recommended by the manufacturer and authorized by its approval. The application of the chemical reference treatment is triggered at the harmfulness threshold (10% of beets with at least one flightless aphid).

Aphid counts are carried out on 25 beet plants, pre-selected and identified using markers, just before each application at T0, T+10 d, and T+19 d and at the end of the test at T+27 d .

The results are expressed as number of wingless green aphids (Myzus persicae) per plant (Table 1) or in number of infested plants out of 100 (Table 2). Table 1:

Table 2:

These examples show that the effect of the mixtures B and C according to the invention is better than the mixture A and is close to that of a reference chemical insecticide.

Claims

1. Method for combating biting insects comprising the application to plants to be treated of microcapsules containing one or more attractant substances which have an attractive effect on predators of said biting insects, the microcapsules having a median diameter D50 of between 0.5 μm and 20 pm, preferably between 0.8 pm and 10 pm.

2. Method according to claim 1, characterized in that the biting insects are aphids and/or mealybugs, preferably aphids.

3. Method according to claim 1 or 2, characterized in that the plant to be treated is chosen from beets; fruit trees such as apple trees, pear trees, peach trees, or plum trees; cereals such as wheat or barley; or even market garden plants such as beans, artichokes, carrots, potatoes, beans, or peas.

4. Method according to any one of claims 1 to 3, characterized in that it further comprises the application to the plants to be treated of an asphyxiating and/or drying insecticide.

5. Method according to claim 4, characterized in that it comprises the application, in particular spraying, to the plants to be treated of a mixture comprising an asphyxiating and/or drying insecticide and said microcapsules.

6. Method according to claim 5, characterized in that the slurry contains, relative to the total weight of the slurry, from 1% to 3%, preferably from 2% to 3% by weight of the asphyxiating insecticide and/or drying agent, from 0.01 to 0.1%, preferably from 0.02% to 0.05% by weight of the microcapsules.

7. Method according to any one of claims 1 to 6, characterized in that the predators of the biting insects are aphidiphagous insects, and in particular braconid, coccinellid, syrphid, anthocorid, chrysopid insects or a combination of these, preferably ladybugs, especially 7-spotted or 11-spotted, lacewings, hoverflies or a combination of these.

8. Method according to any one of claims 1 to 7, characterized in that the attractant substance(s) are p-farnesene alone or mixed with a or substances chosen from camphene, salicylic esters such as methyl salicylate, E-2-hexenal, Z-3-hexenyl acetate, 2-phenyl ethanol, p-ocimene, benzyl alcohol, and a combination of these, the mixture advantageously containing at least 50% by weight of p-farnesene.

9. Method according to any one of claims 1 to 8, characterized in that the asphyxiating and/or drying insecticide is chosen from paraffin, a vegetable oil, a silicone oil, a soap, in particular synthetic or natural, or a combination of these.

10. Composition comprising an asphyxiating and/or drying insecticide and microcapsules containing one or more attractant substances which have an attractive effect on predators of said biting insects, the microcapsules having a median diameter D50 of between 0.5 pm and 20 pm, of preferably between 0.8 pm and 10 pm.

11. Composition according to claim 10 comprising:

- from 30 to 99 parts, preferably from 30 to 99 parts by weight of an asphyxiating and/or drying insecticide,

- from 0 to 30 parts, preferably from 5 to 20 parts by weight of a surfactant, preferably chosen from nonionic surfactants such as polyalkoxylated fatty acids, esters of fatty acid and sorbitan, esters of (poly)alkoxylated fatty and sorbitan acids, alkoxylated alkylphenols, alkoxylated fatty alcohols, fatty acid and glycerol esters and combinations thereof,

- from 0.1 to 4 parts, preferably from 0.6 to 2 parts by weight of microcapsules containing one or more attractant substances, and

- from 0 to 1 parts, preferably from 0.1 to 1 parts by weight of an antifoaming agent such as organosiloxanes and their polymeric forms, organosilicones, polyethers and polyesters of glycerides and combinations thereof.

12. Composition according to claim 10 or 11, characterized in that the attractant substance(s) are p-farnesene alone or in mixture with one or more substances chosen from camphene, salicylic esters such as methyl salicylate, E -2-hexenal, Z-3-hexenyl acetate, 2-phenyl ethanol, [3-ocimene, benzyl alcohol, and a combination thereof, the mixture advantageously containing at least 50% by weight of p -farnesene, and in that the asphyxiating and/or drying insecticide is a paraffin, a vegetable oil, a silicone oil, a soap, in particular synthetic or natural, or a combination of these. Composition according to any one of Claims 10 to 12, characterized in that the microcapsules comprise:

- a heart comprising the attractive substance(s), and

- an outer envelope surrounding the core comprising a HASE type copolymer, optionally neutralized, totally or partially, in the form of a sodium, potassium or ammonium salt, the core further comprising a mixture of wax and oil vegetable or a fatty substance having a melting point ranging from 25°C to 75°C, preferably ranging from 25°C to 70°C, more preferably from 25°C to 65°C, the core advantageously representing 99, 8% to 95% by weight of the total weight of the microcapsules, and the outer shell advantageously representing 0.2% to 5% by weight of the total weight of the microcapsules. Composition according to claim 13, characterized in that the HASE type copolymer is a copolymer of (meth)acrylic acid such as methacrylic acid, of alkyl acrylate such as ethyl acrylate and of a or several hydrophobic macromonomers of formula Chem. I following:

[Chem. I]

in which :

- R a hydrocarbon group of formula C _n H2n+i in which n is an integer between 9 and 25, preferably between 10 and 22, and even more preferably equal to 12, 16 or 22. Composition according to claim 13 or 14, characterized in that the heart comprises, relative to the total weight of the heart, from 1 to 20% by weight of the attractant substance(s) and:

- from 5% to 30% by weight of wax and from 60% to 90% by weight of vegetable oil, or Tl

- from 60% to 90% of a fatty substance having a melting point ranging from 25°C to 75°C, preferably ranging from 25°C to 70°C, more preferably from 25°C to 65°C. Composition according to any one of Claims 13 to 15, characterized in that the vegetable oil is chosen from the group consisting of sunflower oil, peanut oil, soybean oil, rapeseed, corn oil, olive oil, grape oil, walnut oil, flaxseed oil, palm oil, coconut oil, coconut oil argan, avocado oil, almond oil, hazelnut oil, pistachio oil, rice oil, cottonseed oil, wheat germ oil, sesame oil, and mixtures thereof, in that the wax is chosen from waxes of animal origin, waxes of vegetable origin, mineral waxes and mixtures thereof, preferably from beeswax, lanolin wax , Chinese insect wax, rice wax, carnauba wax, candelilla wax, jojoba wax, ouricurry wax, esparto wax, cork fiber wax, wax sugar cane, Japanese wax, sumac wax, montan wax, microcrystalline waxes, and mixtures thereof, and in that the fatty substance having a melting point ranging from 25 ° C to 75 ° C, preferably ranging from 25°C to 70°C, more preferably from 25°C to 65°C, is chosen from hydrogenated or non-hydrogenated coconut oil, beeswax, lanolin wax, solid paraffin, and their mixtures. Process for preparing a composition according to any one of claims 10 to 16 comprising the addition of a suspension of microcapsules as defined in any one of claims 10 to 16 to the asphyxiating and/or drying insecticide, optionally in mixture with the surfactant, and the antifoaming agent, advantageously at a temperature of 15°C to 30°C, preferably of 18°C to 25°C.