FR2695005A1 - Method and products for combating insects based on 4-phenoxy-phenoxymethyl-1,3-dioxolane derivatives - Google Patents

Abstract

The invention relates to a process for combating insects in which compounds of the formula: (CF DRAWING IN BOPI) in which R represents an ethyl or propyl group are used, this process characterized in that insects of the same are combated. the order Homoptera or the order Lepidoptera, the use in this field of these compounds, the corresponding insecticidal products, the active substance of which is chosen from these compounds, as well as a process for the preparation and use of these products, with the proviso that (2R, 4S) -2-ethyl-4- (4-phenoxy) -phenoxymethyl-1,3-dioxolane, as a pure enantiomer or as a product predominantly containing the enantiomer pure, is excluded from all the objects of the invention.

Description

The invention relates to a method for controlling insects, in

  which compounds of formula

O (I),

  in which R represents an ethyl or propyl group, this process being characterized in that insects of the order Homoptera or of the order Lepidoptera are used, the use for this purpose of these compounds, insecticides corresponding active substance is selected from these compounds, and a process for the preparation and use of these products, subject to

  that (2 R, 4 S) -2-ethyl-4- (4-phenoxy) -phenoxymethyl-1,3-

  dioxolane as a pure enantiomer or product containing predominantly this pure enantiomer, is

  excluded from all the objects of the invention.

  In the context of the present invention, the enantiomer (2 R, 4 S) mentioned above is in the form of "product containing predominantly this pure enantiomer", and this enantiomer then falls, inter alia, into the part of the specified reserve, when its proportion in a mixture of compounds of formula I is at least 90%, preferably at least 88%, more especially at least 85%, especially at least 80%, especially at least 70% and especially more than 50%, of the total number of molecules contained

in this mixture.

  In U.S. Patent No. 4,097,581 there are provided compounds of the formula 2- (II), wherein R 1 is hydrogen, C 1 -C 7 alkyl, C 3 cycloalkyl 3-C 6, C 2 -C 3 alkenyl, C 2 -C 3 alkynyl, C 2 -C 4 methoxyalkyl, chloromethyl or benzyl, and R 2 represents hydrogen or C 1 -C 6 alkyl or R 1 and R 2 together represent the group - (CH 2) n in which N is 4 or 5, or together with the carbon atom to which they are attached the group of formula CH 3

H

(III)

CH (CH 3) 2

  as active substances in products used to hasten the abcission of fruits and as active substances in parasiticidal products, for example insecticides, and especially products for the control of insects of the order Diptera and more

  especially of the order Coleoptera.

  It has been surprisingly found, in view of the contents of U.S. Patent No. 4,097,581, that the compounds of formula I are well suited for use in the control of the insects of certain families and certain genera of the species. Order of Homoptera and certain families of the order Lepidoptera, namely the insects of the families Aleyrodidae, Cicadellidae, Coccidae, Margarodidae and Psyllidae belonging to the order Homoptera, insects of the genera Aonidiella, Aspidiotus, Aulacaspis, Chrysomphalus, Lepidosaphes , Parlatoria, -3Pseudaulacaspis, Quadraspidiotus and Unaspis and, belonging to the order Homoptera, of the family Diaspididae, the insects of the genus Planococcus, of the family Pseudococcidae belonging to the order Homoptera, and the insects of families Gracilariidae , Lyonetiidae, Olethreutidae, Psychidae and Tortricidae belonging to

the order Lepidoptera.

  This remarkable ability of the compounds of formula I to use for the control of insects of certain families and certain genera of the order Homoptera and certain families of the order Lepidoptera is all the more surprising that the compounds of Formula I do belong to the class of compounds of Formula II described in US Pat. No. 4,097,581 and are specifically mentioned in the form of mixtures of diastereoisomers in the Table of Columns 9 and 10 of this patent. However, US Pat. No. 4,097,581 does not disclose the remarkable activity of the compounds of formula I of the present invention, nor any specifically labeled activity of compounds of formula II against insects. , specified in the present invention, certain families and certain genera of the order Homoptera and certain families of the order of (lepidopt) res, let alone a specially marked activity in this respect compounds of formula I of the present application, which may be regarded as

  a special subgroup of the compounds of formula II.

  The fight against insects of the type mentioned according to the invention is of great importance for the user in this area, because in the absence of a selective fight against these insects, they can cause large economic losses, under form for example -4-

  damage to agricultural products.

  On the one hand, in the context of the present invention, a method for controlling insects of the specified type in which compounds of formula I in which R represents an ethyl group is preferred. On the other hand, in the context of the present invention, a method for combating 1) insects of the family Coccidae, in particular of the genera Ceroplasts, Pulvinaria and Saissetia, preferably Ceroplasts floridensis, Ceroplasts sinensis, Pulvinaria species, is preferred. psidii and Saissetia olea, especially Ceroplastes floridensis, Ceroplastes sinensis and Saissetia olea, especially Ceroplastes floridensis and Saissetia olea, especially of the species Ceroplastes floridensis, and more particularly of the species Saissetia olea; 2) insects of the species Ceroplastes rubens belonging to the genus Ceroplasts of the family Coccidae; 3) insects of the genera Aonidiella, Lepidosaphes, Parlatoria, Chrysomphalus, Aulacaspis, Aspidiotus, Selenaspidus, Pseudaulacaspis, Quadraspidiotus and Unaspis of the family Diaspididae, preferably species Aonidiella aurantii, Lepidosaphes beckii, Lepidosaphes ulmi, Parlatoria pergandei, Parlatoria blanchardii, Parlatoria ziziphi, Chrysomphalus aonidum, Aulacaspis tubercularis, Aspidiotus hederae, Selenaspidus articulatus, Pseudaulacaspis pentagona, Quadraspidiotus perniciosus, Unaspis citri and Unaspis yanonensis, especially Aonidiella aurantii species, Lepidosaphes beckii, Parlatoria pergandei, Parlatoria -5-blanchardii, Parlatoria ziziphi, Chrysomphalus aonidum , Aulacaspis tubercularis, Selenaspidus articulatus, Pseudaulacaspis pentagona, Quadraspidiotus perniciosus, Unaspis citri and Unaspis yanonensis, especially Aonidiella aurantii, Lepidosaphes beckii, Parlatoria pergandei, Pseudaulacaspis pentagona, Quadraspidiotus perniciosus Unaspis citr and Unaspis yononensis, in particular Aonidiella aurantii, Lepidosaphes beckii, Parlatoria pergandei, Pseudaulacaspis pentagona, Quadraspidiotus perniciosus, Unaspis citri and Unaspis yononensis species, especially Aonidiella aurantii and Lepidosaphes beckii species, especially of the species Aonidiella aurantii, especially species Lepidosaphes beckii; 4) insects of the Margarodidae family, in particular of the genus Icerya, preferably of the species Icerya purchasi; (5) insects of the genus Planococcus of the family Pseudococcidae, genus Psylla of the family Psyllidae, and genus Trialeurodes and Bemisia of the family Aleyrodidae; preferably Planococcus ficus, Planococcus citri, Psylla pyricola, Trialeurodes vaporariorum and Bemisia tabaci, more particularly Planococcus ficus, Psylla pyricola, Trialeurodes vaporariorum and Bemisia tabaci, in particular species Psylla pyricola, Trialeurodes vaporariorum and Bemisia tabaci, especially the species Psylla pyricola; 6) insects of the family Olethreutidae, in particular of the genera Cydia and Laspeyresia, preferably Cydia pomonella, Laspeyresia molesta and Laspeyresia funebrana species, especially Cydia pomonella and Laspeyresia molesta species, in particular of the species Laspeyresia molesta, especially of the species Cydia pomonella; (7) insects of the genus Eupoecilia of the family Olethreutidae, in particular of the species Eupoecilia ambiguella; 8) insects of the family Tortricidae, in particular genera Adoxophyes, Pandemis, Cacoecia and Eulia, preferably species Adoxophyes reticulana, Pandemis heparana, Cacoecia costana, Cacoecia pronubana and Eulia sphaleropa, in particular species Adoxophyes reticulana, Pandemis heparana and Cacoecia pronubana, especially of the species Adoxophyes reticulana; 9) insects of the family Lyonetiidae, in particular of the genera Leucoptera and Lyonetia, preferably species Leucoptera scitella and Lyonetia clerkella, in particular of the species Leucoptera scitella; ) insects of the family Gracilarridae, in particular of the genus Lithocolletis, preferably species Lithocolletis blancardella and Lithocolletis corylifoliella,

  in particular of the species Lithocolletis blancardella.

  The compounds of formula I used according to the invention are known and described for example in

U.S. Patent No. 4,097,581.

  The compounds of formula I used in accordance with the invention are valuable active substances in the field of insect control and which have remarkable preventive and / or curative effects at low application concentrations but are well tolerated by individuals. The active substances used according to the invention are effective in all stages of development or in individual stages of development of insects with normal sensitivity but also resistant insects, of the type specified herein. In this respect, the insecticidal activity of the substances used in accordance with the invention can manifest itself directly, for example by the death of insects, which occurs immediately or after a certain time, for example during a metamorphosis. or indirectly, for example by a reduction in egg laying and / or hatching rates, this good efficiency corresponding to a rate

  at least 50 to 60% mortality.

  The active substances used in accordance with the invention make it possible to combat pests of the type mentioned, that is to say to limit their proliferation or to destroy them, in particular on plants, especially on useful and decorative plants in agriculture, in horticulture and in forests or parts thereof such as fruits, flowers, foliage, stems, tubers or roots, and in some cases parts of plants that grow later

  remain protected against these parasites.

  Among the crops targeted, particular mention will be made of pome fruit crops, for example apples or pears, stone fruits, for example peaches, citrus fruits, for example lemons, oranges or grapefruit, vegetable crops, eg potatoes, beans, tomatoes or cucumbers, pepper, olives, mangos, vines, decorative plants, walnuts, guavas, tea plants or avocados, especially pome fruits, stone fruits, citrus fruits, vegetables, olives, mangoes, vines, decorative plants or nuts, preferably pome fruits, stone fruits or

citrus fruits.

  Among the other fields of application of the active substances used in accordance with the invention are the protection of stores, stores or materials and, in the hygiene sector, in particular the protection of pets or useful animals.

  against parasites of the type mentioned.

  The invention therefore also relates to insecticidal products intended for use against pests of the specified type and which, depending on the purpose and the particular circumstances, are in the form of emulsifiable concentrates, suspension concentrates, directly or dilutable sprayable solutions, extendable pastes, diluted emulsions, slurry powders, soluble powders, dispersible powders, wettable powders, dusting powders, granules or encapsulations in polymeric materials, all these products containing at least one one of the substances

  active agents used in accordance with the invention.

  The active substance is used in these products in pure form, for example at a special grain size when it is a solid substance or, preferably, with at least one of the usual auxiliaries in formulation techniques such as diluents, for example solvents or solvents

  solid vehicles, or surfactants.

  Among the solvents which may be used, mention may be made, for example, of partially hydrogenated aromatic hydrocarbons, preferably the C 8 to C 12 fractions of alkylbenzenes, for example Se xylenes mixtures, alkylated naphthalenes or tetrahydronaphthalene, cycloaliphatic aliphatic hydrocarbons such as paraffins or cyclohexane, alcohols such as ethanol, propanol, butanol, glycols, their ethers and esters, such as propylene glycol, ethers of dipropylene glycol, ethylene glycol, monomethyl or monoethyl ether of ethylene glycol, ketones such as cyclohexanone, isophorone or diacetone alcohol, strongly polar solvents such as N-methylpyrrolidone-2, dimethylsulfoxide or N, N-dimethylformamide, water, optionally epoxidized vegetable oils, for example rapeseed oil, castor oil, coconut oil or possibly soya bean oil poxydées and

silicone oils.

  The solid carriers used, for example, for dusting powders and dispersible powders are generally natural mineral flours such as calcite, talc, kaolin, montmorillonite or attapulgite. To improve the physical properties, it is also possible to add high dispersion silicas or high dispersion absorbent polymers Granular adsorbent granular vehicles include porous types such as pumice, crushed brick, sepiolite or bentonite and among non-sorbent carriers calcite or sand. can also use a large number of materials of inorganic or organic nature previously put in the granular state, in

  particular of dolomite, or crushed vegetable residues.

  Surfactants are, depending on the nature of the active substance used, agents

  surfactants or mixtures of non-surfactant

  ionic, cationic and / or anionic

  emulsifying, dispersing and wetting properties.

  The surfactants listed below are only examples; many other examples of surfactants customary in the formulation and

  suitable for use in the invention.

  Among the nonionic surfactants, mention may be made first of polyglycol ether derivatives of aliphatic or cycloaliphatic alcohols, of saturated or unsaturated fatty acids and of alkylphenols, which contain from 3 to 30 ether groups. of glycol and 8 to 20 carbon atoms in the hydrocarbon radical (aliphatic) and 6 to 18 carbon atoms in the alkyl group of the alkylphenols Also suitable soluble adducts

  in water containing 20 to 250 ethylene ether groups.

  glycol and 10 to 100 propylene glycol ether groups,

  of polyethylene oxides on propylene glycol, ethylene

  diamino-polypropylene glycol and alkylpolypropylene glycol

  containing 1 to 10 carbon atoms in the alkyl chain.

  These compounds usually contain from 1 to 5 ethylene glycol units per propylene glycol unit. For example, nonylphenolpolyethoxyethanols, castor oil polyglycol ethers,

  polyethylene-polypropylene, tributylphenoxypolyethoxy-

  ethanol, polyethylene glycols and octylphenoxypoly-

  ethoxyethanol Further mention will be made of polyoxyethylenated fatty acid and sorbitan esters such as trioleate

polyoxyethylene sorbitan.

  The cationic surfactants are especially quaternary ammonium salts containing, as substituents, at least one C 8 -C 22 alkyl group, the other substituents being optionally halogenated alkyl, benzyl or hydroxyalkyl groups. The salts are preferably halides. methylsulfates or ethylsulfates. For example, stearyltrimethylammonium chloride and sodium bromide are mentioned.

  benzyl-di- (2-chloroethyl) ethylammonium.

  Suitable anionic surfactants may be both water soluble soaps and water soluble synthetic surfactants. Suitable soaps include alkali, alkaline earth and ammonium salts. optionally substituted higher fatty acids (C 10 -C 22) such as the sodium or potassium salts of oleic acid, stearic acid or mixtures of natural fatty acids obtained for example from coconut oil or tall oil; Mention may also be made of methyltaurine salts of fatty acids. In most cases, however, synthetic surfactants are used, in particular sulphonates of fatty derivatives, sulphates of fatty derivatives, sulphonated derivatives of benzimidazole and alkylarylsulphonates. Sulphonates and sulphates derivatives

  are generally in the form of alkaline salts, alkaline

  earth or ammonium optionally substituted and generally contain a C 8 -C 22 alkyl group, this alkyl group may also consist of the alkyl part of an acyl radical; mention may be made, for example, of the sodium or calcium salt of the lignin-sulfonic acid, of the dodecylsulfuric ester or of a mixture of sulphates

  of fatty alcohols prepared from natural fatty acids.

  In this group, mention will also be made of the salts of the sulfuric and sulphonic acid esters of adducts of ethylene oxide with fatty alcohols. The sulphonated derivatives of benzimidazole preferably contain two acid groups.

  sulfonic acid and a C 8 -C 22 fatty acid radical.

  Examples of alkylarylsulphonates are the sodium, calcium or triethanolammonium salts of dodecylbenzenesulfonic acid, dibutylnaphthalenesulphonic acid or a naphthalenesulfonic acid / formaldehyde condensation product. corresponding phosphates, for example the salts of the phosphoric ester of an adduct of 4 to 14 mol of ethylene oxide on p-nonylphenol, or the phospholipids. The products in question contain in general from 0.1 to 99%, more especially from 0.1 to 95% of active substance and from 1 to 99.9%, especially from 5 to 99.9% by weight. at least one solid or liquid auxiliary product with, in general, from 0 to 25%, more especially from 0.1 to 20% of surfactant relative to the total product (all indications of% are by weight). Concentrated products are preferred, but the end user generally uses diluted products with much lower concentrations of active substance. The composition (in% by weight) of certain preferred products is given below: Emulsifiable concentrates active substance 1 to 90%, preferably 5 to 20% surfactant 1 to 30%, preferably 10 to 20% solvent 5 to 98%, preferably 70 to 85% powder for active substance 0.1 to 10%, preferably 0.1 to 1% solid vehicle 99.9 to 90%, preferably 99.9 to 99% Con centered for emulsions active substance 5 to 75%, preferably 10 to 50% water 94 to 24%, preferably 88 to 30% surfactant 1 to 40%, preferably 2 to 30% Wettable powder active substance 0.5 to 90 %, preferably 1 to 80% surfactant 0.5 to 20%, preferably 1 to 15% solid vehicle 5 to 99%, preferably 15 to 98% Granules active substance 0.5 to 30%, preferably 3 to 15%

  solid vehicle 99.5 to 70%, preferably 97 to 85%.

  The activity of the products according to the invention can be considerably enlarged and adapted to certain particular circumstances by the addition of other insecticidal active substances. Among these active additives, mention will be made for example of representatives of the following classes: organic phosphorus compounds, -13 nitrophenols and derivatives, formamidines, ureas, carbamates, pyrethroids, chlorinated hydrocarbons and Bacillus thuringiensis preparations. The products according to the invention may also contain other solid or liquid auxiliary products, such as stabilizers, for example. example of optionally epoxidized vegetable oils (coconut oil, rapeseed oil or

  epoxidized soybean oil for example), anti-

  foam, for example a silicone oil, preservatives, viscosity regulators, binders and / or adhesives or fertilizers or other active substances for special effects, for example bactericides, nematocides,

  mollusquicides or selective herbicides.

  The products according to the invention are prepared in known manner, for example by grinding, sieving, and / or compression of an active substance or a mixture of solid active substances in the absence of auxiliary products, for example one-dimensional determined grain, or by intimate mixing and / or grinding of the active substance or of the mixture of active substances with the auxiliary product or products when using at least one auxiliary product These processes for the preparation of the products according to the invention and the use of the compounds of formula I for the preparation of these products

  also constitute an object of the invention.

  The process for using these products.

  that is to say, the method for controlling pests of the specified type, for example, according to the purpose and the particular circumstances, spraying, fogging, dusting, coating, disinfection, dusting or watering, and the use of products for the control of parasites of the specified type are other objects of the invention. In this respect, the concentrations of applications commonly range from 0.1 to 1. at 1000 ppm, preferably from 0.1 to 500 ppm of active substance In particular, spray mixtures are used at concentrations of active substance of 50, 100, 150 or 200 ppm. The doses applied per hectare are generally 1 to 2000 g of active substance, more preferably 10 to 1000 g / ha, preferably 20 to 600 g / ha. The preferred application rates are 300, 400 or 450 g of active substance per hectare. trees, the preferred application rates are 0 , 25, 0.75, 1.0 or 2.0 g

of active substance per tree.

  A preferred mode of application in the field of plant protection is the application on the foliage of the plants, the frequency of the applications and the doses applied being a function of the infestation pressure of the parasite However, the active substance may also to reach the plants via the roots (systemic activity): the planting site is impregnated with a liquid product or the active substance is introduced in the solid state into the planting place, for example into the soil, for example under the

  pellet form (application in the soil).

  The following examples illustrate the invention without limiting its scope. All temperatures

are given in degrees Celsius.

  Examples of formulation (% = weight percent) Example F1: Concentrates for emulsions a) b) c) active substance 25% 40% 50% dodecylbenzene sulfonate Ca 5% 8% 6% polyethylene glycol ether oil castor oil (at 36 mol of EO) 5% polyethylene glycol ether of tributylphenol (at 30 mol of EO) 12% 4% cyclohexanone 15% 20% xylenes mixture 65% 25% 20% -15- From of these concentrates are diluted with water, emulsions with

any desired.

  Example F 2: Solutions active substance monomethyl ether of ethylene glycol polyethylene glycol, PM 400 N-methyl-2-pyrrolidone epoxidized coconut oil mineral spirits (boiling 160

at 190)

The solutions are suitable for

form of very fine droplets.

  Example F 3: Granules active substance kaolin can a)% prepare, by concentration b)%% -%% c) d)

% 95%

1% 5%

94% the application a) b)

% 10%

94% -

_

  If you have not been able to do so

  attapulgite 90% The dichloromethane active substance is dissolved, applied by spraying

  vehicles and the solvent is evaporated under vacuum.

  Example F 4: Powder for powdering a) active substance 2% silica with high dispersion 1% talc 97% kaolin By intimate mixing of the active substance vehicles, powders are obtained for

ready to use.

  Example F 5: Powders for slurries a) Active substance 25% lignin-Na sulfonate 5% Na lauryl sulphate 3%

  Na diisobutylnaphthalenesulfonate -

  c) 8% 79% 13% in d) 21% 54% 7% 18% the b)%%% with dusting b) c)

% 75%

% -

%

6% 10%

  Polyethyleneglycol ether of 1 W r -1 -1, 1 r; (A 7 _ Q m l r A 1 no 'no,

  1 U Ullllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll

  high dispersion silica 5% 10% 10%

kaolin 62% 27% -

  The active substance is mixed with the additives and milled in a suitable mill. Dried powders are obtained from which suspensions of a concentration can be formed by dilution with water.

any desired.

  Example F 6: Concentrate for active substance emulsions 10% polyethylene glycol ether of octylphenol (at 4-5 mol of EO) 3% dodecylbenzenesulfonate of Ca 3% castor oil polyglycol ether (at 36 mol of OE) 4% cyclohexanone 30% xylenes mixture 50% From this concentrate, it is possible to prepare by dilution with water emulsions at a concentration

any desired.

  Example F 7: Powders for dusting a) b) active substance 5% 8%

talcum 95% -

  kaolin 92% Dusts are obtained for use by mixing the active substance

  vehicle and grinding on a suitable shredder.

  EXAMPLE F 8: Extrusion granules active substance lignin-Na sulfonated carboxymethylcellulose kaolin ready with the% 2% 1% 87% The active substance is mixed with the additives, ground and moistened with water. The mixture is put into the form of granules and then dried in

An air current.

  Example F 9: Granules coated active substance 3% polyethylene glycol, MW 200 3% kaolin 94% The finely ground active substance is applied

  uniformly on kaolin moistened with polyethylene

  glycol in a mixer This gives granules

coated without dust.

  Example F 10: Concentrate for suspension active substance 40% ethylene glycol 10% nonylphenol polyethylene glycol ether (15 mol EO) 6% lignin-Na-sulfonate 10% carboxymethylcellulose 1% aqueous solution of formaldehyde 37% 0.2% silicone oil in the form of 75% aqueous emulsion 0.8% water 32% The finely ground active substance is intimately mixed with the additives. A suspension concentrate is obtained from which it is possible to form by dilution. with water suspensions at a concentration

any desired.

  Biological Examples (% = weight percent unless otherwise stated) Example B1: Activity on Wdoxophyes reticulana (ovicide) Adoxophyes reticulana eggs are immersed on filter paper for a short time in a hydroacetone solution containing 400 ppm of active substance. drying of the eggs, they are incubated in the Petri dishes 6 days later, the hatching rate of the eggs is compared to -18-

  untreated controls (decreased% hatch rate).

  The compounds of formula I have a good activity in this test. In particular, the compound of formula I wherein R represents an ethyl group has an activity greater than 80%. Example B 2: Activity on Aonidiella aurantii Potato tubers are infested by

  crawling larvae ("Crawlern") of Aonidiella aurantii.

  About 2 weeks later, the potatoes are immersed in an aqueous slurry emulsion or suspension

  for spraying containing 400 ppm of active substance.

  After drying the tubers, they are incubated in a plastic container For the evaluation of the results, the survival rate of the creeping larvae of the first successive generation of the treated population is compared 10 to 12 weeks later.

  with that of untreated witnesses.

  The compounds of formula I have a good activity in this test. In particular, the compound of formula I in which R represents an ethyl group has an activity

greater than 80%.

  Example B 3: Activity on Aonidiella aurantii Citrus trifoliata plants are infested by

  crawling larvae ("Crawlern") of Aonidiella aurantil.

  About two weeks later, the plants are sprayed until dripping with an aqueous emulsion spray mixture containing 50 ppm of active substance. The results of the evaluation are compared 10 to 12 weeks later with the survival rate of crawling larvae. of the first successive generation of the treated population

  with that of untreated witnesses.

  The compounds of formula I have a good activity in this test. In particular, the compound of formula t in which R represents an ethyl group has an activity

greater than 80%.

  Example B 4: Activity on Bemisia tabaci Dwarf bean plants are placed in gauze cages and infested by adults of Bemisia tabaci After laying, all adults are removed 10 days later, applied by spray on the plants carrying the nymphs an aqueous emulsion slurry containing 400 ppm of active substance After another 14 days, the hatching rate% of the eggs is compared

to that of untreated witnesses.

  The compounds of formula I have a good activity in this test. In particular, the compound of formula I in which R represents an ethyl group has an activity.

greater than 80%.

  Example B 5: Activity on Bemisia tabaci Dwarf bean plants are placed in gauze cages and infested with adults of Bemisia tabaci. After laying, all adults are removed. Two days later, the plants bearing the eggs are sprayed. Nymphs by an aqueous emulsion slurry containing 400 ppm of active substance After another 10 days, the hatching rate of the eggs is compared to that of untreated controls. The compounds of formula I have a good activity in this test. In particular, the compound of formula I in which R represents an ethyl group has an activity.

greater than 80%.

  Example B 6: Activity on Cydia pomonella (ovicidal) A short time is immersed in a hydroacetone solution containing 400 ppm of active substance of Cydia pomonella eggs deposited on filter paper After drying the solution, the eggs are incubated in boxes 6 days later, the egg hatch rate is determined relative to that of

  untreated controls (decrease hatching rate%).

  The compounds of formula I have a good activity in this test. In particular, the compound of formula I in which R represents an ethyl group has an activity

greater than 80%.

* * * -21-

Claims (15)

  A method for combating insects in which an insecticidal product containing at least one compound of the formula o in which R is ethyl or propyl, as the active substance, and optionally at least one, is applied to the insects or their habitat. auxiliary product, characterized in that insects of the families of Aleyrodidae, Cicadellidae, Coccidae, Margarodidae and Psyllidae belonging to the order Homoptera, insects of the genera Aonidiella, Aspidiotus, Aulacaspis, Chrysomphalus, Lepidosaphes, Parlatoria, Pseudaulacaspis, are controlled. , Quadraspidiotus Selenaspidus and Unaspis of the family Diaspididae belonging to the order Homoptera, insects of the genus Planococcus of the family Pseudococcidae belonging to the order Homoptera, and insects of the families Gracilariidae, Lyonetiidae, Olethreutidae, Psychidae and Tortricidae belonging to the order Lepidoptera,   provided that (2 R, 4 S) -2-ethyl-4- (4-phenoxy) -   phenoxymethyl-1,3-dioxolan in the form of a perfectly pure isomer or in the form of a product containing predominantly this pure isomer, is excluded from the scope of   active substances contained in the product.   2 Process according to claim 1, characterized in that in the compound of formula I, R represents a ethyl group.   Process according to claim 1 or 2, for   to fight the insects of the family Coccidae.   4 Process according to one of claims 1 to 3,   to fight insects of the genera Ceroplasts, Pulvinaria and Saissetia.   Process according to claim 1 or 2 for combating insects of the genera Aonidiella, Lepidosaphes, Parlatoria, Chrysomphalus, Aulacaspis, Aspidiotus, Selenaspidus, Pseudaulacaspis, Quadraspidiotus   and Unaspis of the family Diaspididae.   Process according to claim 1 or 2, for   to fight the insects of the Margarodidae family.   Method according to claims 1, 2 or 6,   to fight insects of the genus Icerya.   Process according to claim 1 or 2 for combating insects of the genus Planococcus of the family Pseudococcidae, genus Psylla of the family Psyllidae and genera Trialeurodes and Bemisia de la family of Aleyrodidae.   The method of claim 1 or 2 for   to fight the insects of the family Olethreutidae.   A method according to claim 1 or 2 or 9 for combating insects of the genus Cydia and Laspeyresia. Method according to claim 1 or 2, for   to fight the insects of the family Tortricidae.   The process according to claim 1, 2 or 11 for combating insects of the genus Adoxophyes, Pandemis, Cacoecia and Eulia.   Method according to claim 1 or 2, for   to fight the insects of the family Lyonetiidae.   Process according to claim 1, 2 or 13 for combating insects of the genera Leucoptera and Lyonetia. Method according to claim 1 or 2, for   to fight the insects of the family Gracilariidae.   Process according to claim 1, 2 or 15,   to fight insects of the genus Lithocolletis.   An insecticidal product for use in a process according to claim 1, characterized in that the product contains at least one compound of the formula GOLD   in which R represents an ethyl or propyl group, as active substance, and where appropriate at least one   auxiliary product, provided that (2 R, 4 S) -2-ethyl-4-   (4-phenoxy) -phenoxymethyl-1,3-dioxolan, in the pure isomer state or in the form of a product containing mainly this pure isomer, is excluded from the scope of the   active substances contained in the product.   Product according to Claim 17, characterized in that, in the compound of formula 1, R represents an ethyl group.   19 Process for the preparation of a product according to claim 17, containing at least one auxiliary product, characterized in that the active ingredient is intimately mixed and / or ground with the product or products Auxiliary.   Use of a compound of formula o and> to (1 I), wherein R is ethyl or propyl, provided that the compound of formula I can not   (2 R, 4 S) -2-ethyl-4- (4-phenoxy) -phenoxymethyl-1,3-   dioxolane as a pure enantiomer or a produilt containing mainly the pure enantiomer, for the preparation of a product according to claim 17. Using a product as described in claim 17 in a process as described in claim 1. * * *