Biological method for controlling biting insects

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

[0001] DESCRIPTION

[0002] Title: BIOLOGICAL PROCESS FOR CONTROLLING BITING INSECTS

[0003] TECHNICAL FIELD OF THE INVENTION

[0004] The present invention relates to a method for controlling 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 may be used in combination with an asphyxiating and / or desiccating insecticide. The present invention therefore also relates to a composition comprising microcapsules containing one or more attractant substances and an asphyxiating and / or desiccating insecticide, and a method for preparing the same.

[0005] STATE OF THE ART

[0006] Aphids are biting insects that cause significant damage to crops due to the injuries they inflict on plants and the diseases they can carry. Aphids are also capable of reproducing through mating and parthenogenesis, making them very prolific.

[0007] The first method of control is to use molecular insecticides, synthetic such as products based on cypermethrin, lambda-cyhalothrin or deltamethrin, or natural such as pyrethrum-based products 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 occurs 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 have had to gradually increase the doses or frequency of treatments applied, which has had the effect of further improving the selection of resistant strains, ultimately leading to a situation where the insecticide becomes ineffective.The public authorities have therefore reacted by forcing users to alternate insecticides to limit the effects of selection, but this tactic only delays the development of resistance.

[0008] Furthermore, increasing doses and using molecules that are increasingly toxic to aphids cannot be achieved without sometimes serious consequences for biodiversity and sometimes even for humans. The growing difficulty of reconciling the effectiveness of chemical insecticides with respect for health and the environment is clearly described in: Report of the National Centre of Expertise on Vectors, 2014. Use of insecticides and resistance management.

[0009] A second method of control with insecticides exists and consists of using fatty or surfactant substances such as paraffins, vegetable oils or soaps. These products sprayed on plants attacked by aphids have an asphyxiating effect (for paraffins) and drying effect (for soaps or surfactants) 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 themselves one pass is never sufficient and the proliferation of aphid populations from hidden foci in the vegetation requires numerous passes 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 pollution of soil and runoff water is not negligible in the long term. Such products are described in particular in EP3442333.

[0010] A third biological control method has consisted of releasing aphid predators such as aphidiphagous ladybugs, lacewings, and hoverflies. These insects, in larval or adult form, are capable of eliminating aphid colonies, but their effect is delayed compared to the aphid invasion, since enough aphids are needed for their predators to develop sufficiently to have a cleaning effect on a crop. Depending on climatic effects, predator releases may have to be repeated several times, and the farmer cannot know whether the ladybugs or lacewings will remain in his fields or prefer to move to neighboring areas richer in aphids, such as wooded areas.While artificial repopulation of an area with aphid predators can improve the health of a plot in the long term, the logistical constraints of organizing these releases and the low certainty of their effectiveness on the year's yield do not make it an economically sustainable solution. Furthermore, if the farmer is forced to use an insecticide due to other infestations, he will impact this reintroduced insect population and lose his protection against aphids. There is therefore a need to find solutions for controlling biting insects, such as aphids, offering a better sustainable footprint than chemical insecticides, longer effectiveness than asphyxiating and / or drying insecticides and greater effectiveness than artificial releases of predators.Furthermore, the artificial nature of these releases requires the introduction of foreign species into ecosystems, which can have unpredictable destabilizing effects.

[0011] Large-scale crop protection methods are mainly implemented by spraying. Capsule suspensions suitable for these application methods must have particles smaller than 20 micrometers. Prior art semiochemical encapsulation methods are unsatisfactory due to the viscosity of the suspensions and the resulting particle sizes, which cause clogging of the spraying means. This viscosity is particularly linked to the size of the particles for encapsulation. It is therefore necessary to find a solution that is easy to implement, i.e., easily sprayable.

[0012] The applicant has therefore found a way to use predators present in the ecosystem to effectively combat aphids, while optimizing application costs.

[0013] SUMMARY OF THE INVENTION

[0014] This method consists of using 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 the predators of these biting insects, such as aphidiphagous ladybirds, lacewings or hoverflies. These microcapsules therefore have the effect of attracting these predators to the plot to clean up the hotbeds of biting insects, such as aphids, and possibly to prevent the arrival of new hotbeds of biting insects, such as aphids.

[0015] Thus, the subject of the present invention is 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. Advantageously, the method will further comprise 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 comprise the application, in particular spraying, to the plants to be treated of a mixture comprising an asphyxiating and / or drying insecticide and said microcapsules.

[0016] The present invention therefore also relates to a composition comprising said asphyxiating and / or drying insecticide and said microcapsules.

[0017] According to a first embodiment, the composition comprises from 1% to 3%, preferably from 2% to 3% by weight of the asphyxiating and / or desiccating 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.

[0018] According to a second embodiment, the composition comprises from 30% to 99%, preferably from 60% to 99% by weight of the asphyxiating and / or desiccating insecticide, and from 0.1% to 4%, preferably from 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.

[0019] Such a composition may also comprise a surfactant, an antifoaming agent, one or more additives, advantageously chosen from antimicrobial agents, anti-oxidant agents and mixtures thereof.

[0020] 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 in a mixture with the surfactant, the antifoaming agent, and the additives, when present, advantageously at a temperature of 15°C to 30°C, preferably of 18°C ​​to 25°C.

[0021] DETAILED DESCRIPTION OF THE INVENTION

[0022] Method

[0023] 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.

[0024] This method can be used to treat plants such as beets; fruit trees such as apple, pear, peach, or plum trees; cereals such as wheat or barley; market garden plants such as beans, artichokes, carrots, potatoes, beans, or peas, etc.

[0025] For the purposes of the present invention, the term "biting insect", also known as a piercing-sucking insect or sucking insect, means an insect that feeds on the sap of plants, by biting these plants and then sucking the sap. This more particularly concerns aphids and / or scale insects, preferably aphids.

[0026] For the purposes of the present invention, the term "attractive substance" means 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, coccinellid insects (ladybirds), syrphids, anthocorids, chrysopids or a combination thereof. Preferably, they are ladybirds, in particular 7-spotted or 11-spotted ladybirds, lacewings, hoverflies or a combination thereof.

[0027] The attractant substance(s) will more particularly be p-farnesene (e.g. Ep-farnesene) alone or in a mixture with one or more substances chosen from camphene, salicylic esters (especially 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 may in particular be p-farnesene (e.g. Ep-famesene) alone or in a mixture with camphene, the mixture advantageously containing at least 50% by weight of p-farnesene.

[0028] Advantageously, the method according to the invention will further comprise 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 comprise the application, in particular spraying, on the plants to be treated of a mixture comprising an asphyxiating and / or drying insecticide and said microcapsules. The mixture may contain, relative to the total weight of the mixture, 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.

[0029] Microcapsules

[0030] 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.

[0031] For the purposes of the present invention, the term “median diameter D50” of microcapsules means the median diameter of a distribution of microcapsules, i.e. the diameter such that 50% of the microcapsules by volume have a diameter less than 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.

[0032] Preferably, the microcapsules according to the invention comprise a core containing the attractive substance(s), this core being surrounded by a solid outer shell. Advantageously, the microcapsules comprise:

[0033] - a core comprising a mixture of wax, vegetable oil and the attractant substance(s).

[0034] - an outer shell surrounding the core comprising a HASE-type copolymer, optionally neutralized, totally or partially, in the form of a sodium, potassium or ammonium salt,

[0035] According to another embodiment, the microcapsules comprise:

[0036] - 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).

[0037] - an outer shell surrounding the core comprising a HASE-type copolymer, optionally neutralized, totally or partially, in the form of a sodium, potassium or ammonium salt.

[0038] Heart of microcapsules

[0039] The core of the microcapsules advantageously represents from 99.8% to 95% by weight of the total weight of the microcapsules. The core comprises the attractive substance(s), advantageously in admixture with a wax and an oil.

[0040] Preferably, the core comprises, in particular is constituted by, a mixture of wax, oil, the attractive substance(s), and one or more additives, preferably chosen from an anti-UV additive, an antioxidant and a mixture thereof.

[0041] The heart will advantageously contain, in relation to the weight of the heart:

[0042] — from 5% to 30% by weight of wax,

[0043] — from 60% to 90% by weight of vegetable oil, and

[0044] — from 1% to 20% by weight of the attractant substance(s).

[0045] In addition, the core may contain from 0% to 7% additives.

[0046] According to an alternative embodiment, the core comprises, in particular is constituted by, a mixture of a fatty substance, the attractive substance(s), and one or more additives, preferably chosen from an anti-UV additive, 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 (for example from 30°C to 60°C).

[0047] According to this same embodiment, the heart will advantageously contain, in relation to the weight of the heart:

[0048] — 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 (for example from 30°C to 60°C), and

[0049] — from 1% to 20% by weight of the attractant substance(s).

[0050] In addition, the core may contain from 0% to 7% by weight of one or more additives.

[0051] For the purposes of the present invention, the term "wax" means a lipophilic compound that is 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.

[0052] The waxes that may be used in a composition according to the invention may be chosen from waxes of animal origin, waxes of vegetable origin, mineral waxes, synthetic waxes and mixtures thereof. As wax of animal origin, mention may be made of beeswax, lanolin wax, or Chinese insect wax. As wax of vegetable origin, mention may be made of rice wax, carnauba wax, candelilla wax, jojoba wax, ouricurry wax, alfa wax, cork fiber wax, sugar cane wax, Japanese wax, or sumac wax. As mineral wax, mention may be made of montan wax, microcrystalline waxes, paraffins, or ozokerite. Examples of synthetic waxes include polyethylene waxes, waxes obtained by Fisher-Tropsch synthesis, or waxy copolymers and their esters.Hydrogenated derivatives of the waxes mentioned above may also be used as waxes in the context of the present invention. Mention may also be made of waxes obtained by catalytic hydrogenation of oils of animal or vegetable origin having unsaturated, linear or branched, C8-C32 fatty chains. Among these, mention may in particular be made of hydrogenated jojoba oil, hydrogenated sunflower oil, hydrogenated castor oil, hydrogenated coconut oil, or even hydrogenated lanolin oil, as well as di-(trimethylol-1,1,1-propane) tetrastearate. Waxes obtained by transesterification and hydrogenation of oils of plant origin, such as castor or olive oil, can also be used, such as the waxes sold under the names Phytowax ricin 16L64®, Phytowax ricin 22L73® and Phytowax Olive 18L57® by the company SOPHIM.

[0053] Advantageously, the wax is selected from the group consisting of beeswax, lanolin wax, Chinese insect wax, rice wax, carnauba wax, candelilla wax, jojoba wax, ouricurry wax, alfa wax, cork fiber wax, sugarcane wax, Japanese wax, sumac wax, montan wax, microcrystalline waxes, and mixtures thereof.

[0054] For the purposes of the present invention, the term "oil" means a fatty compound, liquid at room temperature and atmospheric pressure, immiscible with water and non-volatile.

[0055] 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, linseed 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 mixtures thereof.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), capable of being used in a composition according to the invention may be chosen from hydrogenated or non-hydrogenated coconut oil, beeswax, lanolin wax, solid paraffin, and mixtures thereof.

[0056] 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 thereof.

[0057] Anti-UV additives or antioxidants well known to those skilled in the art may be added to limit the oxidation reactions caused by oxygen at 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 4-tetramethyl-piperidine derivatives, notably known as HALS (hindered amine light 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).

[0058] The outer shell of the microcapsules will advantageously represent from 0.2% to 5% by weight of the total weight of the microcapsules.

[0059] The envelope will advantageously comprise a HASE type copolymer, optionally neutralized, totally or partially, in the form of a sodium, potassium or ammonium salt.

[0060] 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, for the purposes of the present invention, a copolymer of (meth)acrylic acid (e.g. methacrylic acid), alkyl acrylate (e.g. ethyl acrylate) and one or more hydrophobic macromonomers of the following Chem. I formula: [Chem. I] in which:

[0061] - m is an integer greater than or equal to 5, in particular between 10 and 40, preferably between 10 and 30, and

[0062] - 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 R group is therefore hydrophobic.

[0063] By "neutralized, totally or partially", is meant, for the purposes 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 the form of sodium, potassium or ammonium salt.

[0064] Advantageously, the HASE type copolymer comprises, in particular is made up of, relative to the total weight of the copolymer:

[0065] - between 30% and 40% by weight of repeating units derived from methacrylic acid,

[0066] - between 45% and 60% by weight of repeating units derived from ethyl acrylate, and

[0067] - between 5% and 20% by weight of repeating units derived from a macromonomer of the following Chem. I formula:

[0068] [Chem. I] in which:

[0069] ■ m is an integer greater than or equal to 5, in particular between 10 and 40, preferably between 10 and 30, and

[0070] ■ 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.

[0071] The HASE-type copolymer may be prepared, for example, according to one of the methods described in WO2011 / 104599, WO201 1 / 104600 and EP1778797. It may be Pharma 38 or Viscoatex 730LV from Coatex. The microcapsules according to the invention may be 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.

[0072] Such a suspension may be prepared in accordance with the procedures described in US2018 / 0064102.

[0073] Thus, microcapsules can be prepared by a process comprising the following steps:

[0074] (a) the preparation of a fatty phase comprising:

[0075] - the wax and the 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),

[0076] - the attractant substance(s), and

[0077] - possibly one or more additives, the fatty phase having a temperature higher than the melting temperature of the wax or fatty substance,

[0078] (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 temperature substantially identical to that of the fatty phase,

[0079] (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

[0080] (d) acidification to a pH of 6 to 7.5, preferably 6.5 to 7.2.

[0081] Step (a)

[0082] The fatty phase is prepared in step (a) so as to obtain a mixture of wax / oil or fatty substance, attractive substance(s), and optionally one or more additives having the composition of the core described above.

[0083] The fatty phase is maintained, preferably with stirring, at a temperature above 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 above the melting temperature of the wax, then adding the wax, then adding the attractant(s).

[0084] Step (b)

[0085] 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. from 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.

[0086] 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.

[0087] This aqueous solution is then heated to a temperature substantially identical to that of the fatty phase.

[0088] By "temperature substantially identical" 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, compared to the temperature of step (a). Preferably, the temperature of step (b) will be identical to that of step (a).

[0089] Thus, the aqueous solution is advantageously at a temperature of 50°C to 85°C, in particular 60°C to 80°C.

[0090] Step (c)

[0091] In this step, the fatty phase having the temperature of step (a) is added to the aqueous solution having the temperature of step (b).

[0092] The mixture is then stirred 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 allows the HASE-type copolymer present in the aqueous solution to precipitate onto the droplets, which then become microcapsules comprising the fatty phase-based core surrounded by the solid shell based on the HASE-type copolymer. These particles are dispersed in water and thus form an aqueous suspension of the microcapsules.

[0093] 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 thereof, in particular phosphoric acid, until a pH of 6 to 7.5, preferably 6.5 to 7.2, is reached. This acid is preferably added in the form of an aqueous solution.

[0094] The temperature of the aqueous suspension of microcapsules thus obtained is then advantageously brought to a temperature below the melting point of the wax, in particular to a temperature between 20°C and 30°C.

[0095] Asphyxiating and / or drying insecticide

[0096] For the purposes of the present invention, the term "asphyxiating and / or drying insecticide" means a liquid substance which asphyxiates and / or dries out the biting insect when this substance coats the biting insect, in particular when the biting insect is covered by said substance.

[0097] 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 of these, preferably a paraffin.

[0098] The paraffin may more particularly be a liquid paraffin having a pour point lower than -5°C, notably measured according to the ASTM D97 standard.

[0099] The vegetable oil may be as defined above.

[0100] The soap can be black soap.

[0101] The asphyxiating and / or desiccating insecticide may be more particularly in the form of an emulsion, for example in a mixture with a surfactant and / or an antifoaming agent. The surfactant will preferably be chosen from non-ionic surfactants such as polyalkoxylated fatty acids, sorbitan fatty acid esters, (poly)alkoxylated sorbitan fatty acid esters, alkoxylated alkylphenols, alkoxylated fatty alcohols, glycerol fatty acid esters and combinations thereof.

[0102] The antifoaming agent may be chosen from organosiloxanes and their polymeric forms, organosilicones, polyethers and polyesters of glycerides and combinations thereof.

[0103] Composition

[0104] The composition according to the invention comprises said asphyxiating and / or drying insecticide and said microcapsules comprising the attractant substance(s).

[0105] The asphyxiating and / or drying insecticide and the microcapsules comprising the attractant substance(s) are in particular as defined above.

[0106] Preferably, the composition comprises from 1 to 3 parts, preferably from 2 to 3 parts by weight of the asphyxiating and / or desiccating insecticide, and from 0.01 to 0.1 parts, preferably from 0.02 to 0.05 parts by weight of the microcapsules.

[0107] According to a first embodiment, the composition comprises from 1% to 3%, preferably from 2% to 3% by weight of the asphyxiating and / or desiccating 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.

[0108] According to a second embodiment, the composition comprises from 30% to 99%, preferably from 60% to 99% by weight of the asphyxiating and / or desiccating insecticide, and from 0.1% to 4%, preferably from 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.

[0109] The composition according to the invention may also contain a surfactant (to form an emulsion) and / or an antifoam agent (to prevent the formation of foam during the preparation of the emulsion). The surfactant and the antifoam agent are in particular as defined above.

[0110] The composition may therefore include:

[0111] - from 30 to 99 parts, preferably from 60 to 99 parts by weight of the asphyxiating and / or drying insecticide,

[0112] - 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

[0113] - from 0 to 1 parts, preferably from 0.1 to 1 parts by weight of an antifoaming agent. When in the form of a concentrated premix, the composition will advantageously comprise, relative to the total weight of the composition:

[0114] - from 30% to 99%, preferably from 60% to 99% by weight of the asphyxiating and / or drying insecticide,

[0115] - from 0% to 30%, preferably from 5% to 20% by weight of a surfactant,

[0116] - from 0.4% to 4%, preferably from 0.6% to 2% by weight of the microcapsules containing the attractive substance(s), and

[0117] - from 0% to 1%, preferably from 0.1% to 1% by weight of an antifoaming agent.

[0118] The composition may also comprise 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 at a level of 0.1 to 2 parts by weight (e.g. at a level of 0.1% to 2% by weight in the premix).

[0119] The antimicrobial agent may be chosen from hydrogen peroxide, peracetic acid, perpropionic acid, and products from the isothiazole family.

[0120] The antioxidant agent may be chosen from butylhydroxytoluene, tocopherol, and oxybenzone.

[0121] The composition according to the invention is in particular in the form of an inverse emulsion.

[0122] Such a composition may be prepared by a process comprising adding a suspension of the microcapsules to the asphyxiating and / or desiccating insecticide, optionally in admixture with the surfactant, the antifoaming agent, and the additives, when present, advantageously at a temperature of 15°C to 30°C, preferably of 18°C ​​to 25°C.

[0123] Thus, when the composition comprises a surfactant, an antifoaming agent, and / or one or more additives, the preparation process advantageously comprises: - mixing the asphyxiating and / or drying insecticide, the optional surfactant, the optional antifoaming agent, and the optional additives, preferably at a temperature of 15°C to 30°C, preferably 18°C ​​to 25°C, then

[0124] - the addition of a suspension of microcapsules.

[0125] FIGURES

[0126] [Fig. 1]: Image of the microcapsules of example 2 obtained under an optical microscope with a x640 zoom.

[0127] [Fig. 2]: Image of the premix of example 4 obtained under an optical microscope with a x640 zoom.

[0128] EXAMPLES

[0129] Ep-farnesene, other attractants, polyethylene glycol monooleate and antioxidants such as BHT or tocopherol are sourced from Sigma Aldrich.

[0130] The HASE type copolymer used in the examples is Pharma 38 supplied by the company Coatex.

[0131] The sunflower oil used in the examples is a commercial Isio 4 sunflower oil.

[0132] The bleached beeswax is supplied by the company Prayon.

[0133] The antifoam agent is supplied by DOW (DC62) or BYK (BYK-1630).

[0134] Viscosities are measured using a Brookfield DV1 viscometer equipped with a chamber.

[0135] The size of the microcapsules is measured by light diffraction analysis with a Mastersizer 3000 device by laser beam diffraction. The measurement protocol is as follows:

[0136] The samples are first prepared by dispersing 0.5g of formulation in 100ml of demineralized water under magnetic stirring for 10 min. Then the particle sizes are measured, taking care first 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 attractant substance contents is carried out by gas chromatography (GC) with a flame ionization detector on an Agilent - HP series II 5890 device.

[0137] The studies on the release of attractant substances are carried out in ventilated ovens without a window 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 GC. Optical microscopy is carried out on a ZEISS AXIO PLAN 2 microscope. Sample observations are carried out in transmission mode with a 40x plan and 20x plan objective. A ZEISS AxioCam ICC3 camera allows images to be viewed on a computer screen.

[0138] Example 1: Production of a suspension of Ep-farnesene microcapsules

[0139] In a three-necked flask No. 1 equipped with a mechanical anchor stirrer, demineralized water 126g and HASE copolymer 15g are introduced. 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 are stirred at 70°C: vegetable oil (coconut oil) 71.8g, Ep-farnesene 13.7g, a-tocopherol 1.3g, BHT 1.3g, and oxybenzone 1.3g. The contents of three-necked flask No. 2 are poured onto the contents of three-necked flask No. 1 while stirring (600 rpm) at a temperature of 70°C. Three-necked flask No. 1 is then left stirring (600 rpm) for 1 h 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 is then added while stirring (300 rpm) followed by a sufficient quantity of 5g of demineralized water.

[0140] The microcapsule suspension obtained has a viscosity of 101000 cP at 3 rpm and 20°C (Brookfield DV1 viscometer with LV5 spindle) and a median diameter D50 of 1.9 μm.

[0141] The release of Ep-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 characteristic half-life time of the diffusion of Ep-farnesene at 30°C is 13 days.

[0142] Example 2: Preparation of microcapsules of a mixture of substances attracting ladybugs and lacewings (50 / 50 Ep-farnesene / camphene) In a three-necked flask No. 1 equipped with an anchor-type mechanical stirrer are introduced demineralized water 135g, and the HASE-type copolymer 8.7g. 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 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) 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.0.2g of 35% H2O2 is then added with stirring (300 rpm) followed by a sufficient quantity of 12g of demineralized water.

[0143] The obtained microcapsule suspension has a viscosity of 800 cP at 20°C, 6 rpm (Brookfield DV1 viscometer with SC4-16 spindle) and a median diameter D50 of 10.6 μm. The microcapsules were observed under an optical microscope with a x640 zoom. The obtained image is presented in Figure 1.

[0144] Example 3: Using microcapsules to attract beneficial insects - trapping demonstration

[0145] 0.5 g of a suspension of microcapsules according to example 1 or 2 is placed on a yellow glue plate trap measuring 20 cm x 20 cm. The attractant substance begins to be released approximately 24 hours after placement, once the water in the composition has evaporated.

[0146] In a mixed orchard (apple, peach, plum, cherry) and vegetable garden (beans, potatoes, artichokes) located in the commune of Pern in the Lot (France), measuring 30mx30m, on supports located 1m to 1.5m from the ground, 5 glued plates measuring 20cmx20cm with the microcapsule suspension of example 1, 5 lacquers with the microcapsule suspension of example 2 and 5 plates which are blank and will serve as a control population. The glued plates are distributed so that they are spaced 5m apart, taking care to be at least 5m from the edge of the garden. Each week, a survey of the traps is carried out and the number of trapped insects is counted, identifying their nature. The number of ladybugs, lacewings, and the rest of the trapped insects (flies, hymenoptera, lepidoptera, etc.) are reported and grouped into a single count. The experimental period is from May 1 to May 31.The results obtained are presented in Table 1 below.

[0147] [Table 1]

[0148] This example shows that traps equipped with the microcapsule suspensions of Example 1 or Example 2 attract more ladybugs and lacewings 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.

[0149] Example 4: Production of a concentrated premix on a 15L Unimix unit with a constant dose (2%) of microcapsules

[0150] 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.

[0151] A second phase consists of adding the antifoam agent DC62 (0.03 kg) or BYK-1630 (0.04 kg). The medium is stirred at a speed of 1000 rpm for 8 min at 25°C.

[0152] A third phase consists of the addition of the microcapsule suspension (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.

[0153] 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 spindle).

[0154] 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: Production of a concentrated premix on a Unimix 15L unit with a constant dose (4%) of capsules

[0155] 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), antifoaming agent BYK-1630 (0.04 kg), microcapsule suspension (970 g) prepared according to Example 2.

[0156] 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 spindle).

[0157] Example 6: Preparation of a spray mixture

[0158] Dilutions of 20L / ha are targeted, i.e. 20L in 1000L of water (volume sprayed on 1 ha). 8.5L of water is added to a 15L mixer and 0.15L of the premix from Example 4 is poured in while stirring. A paraffin emulsion with suspended microparticles is obtained.

[0159] The resulting mixture is sprayed onto a support and observed by optical microscopy.

[0160] Example 7: Preparation of microcapsules of a mixture of aphid repellent and attractants for ladybirds and lacewings (50 / 50 EP-farnesene / methyl salicylate)

[0161] In a three-necked flask No. 1, equipped with an anchor-type mechanical stirrer, demineralized water (1075 g) and the acrylic encapsulating agent Pharma38 from Arkema (70 g) are introduced. 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), methyl salicylate (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 under 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 under 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, SC4-16 spindle) and a median diameter of D50s = 14.5 pm.

[0162] Example 8: Preparation of microcapsules of a mixture of attractants for ladybugs and lacewings (50 / 50 b-farnesene / Methyl Salicylate)

[0163] In a three-necked flask No. 1, equipped with an anchor-type mechanical stirrer, demineralized water (1075 g) and the acrylic encapsulating agent Pharma38 from Arkema (70 g) are introduced. 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, 387 g), beeswax (43 g), EP-farnesene (110 g), methyl salicylate (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 under 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.

[0164] The suspension of microcapsules No. 2 thus obtained has a viscosity of 1,260 cP at 20°C, 6 rpm (Brookfield viscometer, SC4-16 spindle) and a median diameter D50 of 13.4 pm.

[0165] Example 9: Production of a sprayable slurry composed of mineral oil and microcapsules.

[0166] The sprays are prepared directly in a portable spray application device (wheelbarrow type) associated with a carbon bar (e.g.: ESCARRPULV200Z from Zeppelin).

[0167] The sprays consist of dissolving the various mixtures / products to be tested in water, the total quantity of which is calculated for an application volume of 300 L / ha. Spray A: Self-emulsifying mineral oil (1500 mL) Oviphyt® from De Sangosse dissolved with stirring in 28.5 L of water under the conditions provided by the manufacturer.

[0168] Porridge B (according to the 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 De Sangosse self-emulsifying mineral oil.

[0169] Porridge C (according to the 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 De Sangosse self-emulsifying mineral oil.

[0170] Example 10: Use of sprays 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.

[0171] The test plots are located in Beauce, France.

[0172] Each modality is applied on a square plot of 100m 2 surrounded by a 25 m wide strip of cultivation, to avoid any interaction with the rest of the plot. Each method is repeated 3 times.

[0173] Sprays 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 days.

[0174] Flonicamid (50 WG) is used as recommended by the manufacturer and authorized by its registration. The application of the chemical reference treatment is triggered at the pest threshold (10% of beets with at least one apterous aphid).

[0175] Aphid counts are carried out on 25 beet plants, preselected and identified using markers, just before each application at T0, T+10 d, and T+19 d and at the end of the trial at T+27 d.

[0176] The results are expressed as the number of apterous green aphids (Myzus persicae) per plant (Table 1) or as the number of infested plants per 100 (Table 2). Table 1:

[0177] Table 2: These examples show that the effect of sprays B and C according to the invention is better than spray A and is close to that of a reference chemical insecticide.

Claims

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

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

3. Method according to claim 1 or 2, characterized in that the plant to be treated is chosen from among beets; fruit trees such as apple, pear, peach, or plum trees; cereals such as wheat or barley; or vegetable plants such as broad 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 on the plants to be treated of an asphyxiating and / or desiccating insecticide.

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

6. Method according to claim 5, characterized in that the slurry contains, in relation to the total weight of the slurry, 1% to 3%, preferably 2% to 3% by weight of the asphyxiating and / or desiccating insecticide, 0.01% to 0.1%, preferably 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 aphidophagous insects, and in particular braconid insects, ladybugs, hoverflies, anthocorids, lacewings or a combination thereof, preferably ladybugs, in particular 7-spot or 11-spot ladybugs, lacewings, hoverflies or a combination thereof.

8. A method according to any one of claims 1 to 7, characterized in that the attractant substance(s) are p-farnesene alone or in a mixture with a or substances selected 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 thereof, 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 desiccating insecticide is selected from a paraffin, a vegetable oil, a silicone oil, a soap, in particular synthetic or natural, or a combination thereof.

10. Composition comprising an asphyxiating and / or desiccating 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 between 0.5 pm and 20 pm, preferably between 0.8 pm and 10 pm.

11. Composition according to claim 10 comprising: - 30 to 99 parts, preferably 30 to 99 parts by weight of an asphyxiating and / or desiccating insecticide, - from 0 to 30 parts, preferably from 5 to 20 parts by weight of a surfactant, preferably selected from non-ionic surfactants such as polyalkoxylated fatty acids, fatty acid and sorbitan esters, (poly)alkoxylated fatty acid and sorbitan esters, alkoxylated alkylphenols, alkoxylated fatty alcohols, fatty acid and glycerol esters and their combinations, - 0.1 to 4 parts, preferably 0.6 to 2 parts by weight of microcapsules containing one or more attractant substances, and - 0 to 1 parts, preferably 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) is / are p-farnesene alone or in a mixture with one or more substances selected 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 desiccating insecticide is a paraffin, a vegetable oil, a silicone oil, a soap, in particular synthetic or natural, or a combination thereof. Composition according to any one of claims 10 to 12, characterized in that the microcapsules comprise: - a core containing attractive substance(s), and - an outer shell 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 vegetable oil or a fat having a melting point from 25°C to 75°C, preferably 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, alkyl acrylate such as ethyl acrylate, and one or more hydrophobic macromonomers of Chem. formula. Next: [Chem. I] in which: - m is an integer greater than or equal to 5, specifically 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 more preferably equal to 12, 16 or 22. Composition according to claim 13 or 14, characterized in that the core comprises, relative to the total weight of the core, from 1 to 20% by weight of the attractant substance(s) and: - 5% to 30% by weight of wax and 60% to 90% by weight of vegetable oil, or Tl - 60% to 90% of a fat having a melting point of 25°C to 75°C, preferably from 25°C to 70°C, more preferably from 25°C to 65°C. A composition according to any one of claims 13 to 15, characterized in that the vegetable oil is selected from the group consisting of sunflower oil, peanut oil, soybean oil, rapeseed oil, corn oil, olive oil, grape oil, walnut oil, linseed 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, and in that the wax is selected 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, and wax of candelilla, jojoba wax,Ouricurry wax, esparto grass wax, cork fiber wax, sugar cane wax, Japanese wax, sumac wax, montan wax, microcrystalline waxes, and mixtures thereof, and in that the fat having a melting point of 25°C to 75°C, preferably 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 mixtures thereof. A method for preparing a composition according to any one of claims 10 to 16 comprising adding a suspension of microcapsules as defined in any one of claims 10 to 16 to the asphyxiating and / or desiccating insecticide, optionally mixed with the surfactant and the antifoaming agent, advantageously at a temperature of 15°C to 30°C, preferably 18°C ​​to 25°C.

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