GB2058569A

GB2058569A - Liquid insecticide compositions containing synthetic pyrethroids

Info

Publication number: GB2058569A
Application number: GB8029489A
Authority: GB
Original assignee: Montedison SpA
Current assignee: Montedison SpA
Priority date: 1979-09-12
Filing date: 1980-09-12
Publication date: 1981-04-15
Also published as: IT7925634A0; NL8005055A; DK381680A; BE885221A; IN151596B; IT1123122B; JPS5655303A; AU6214580A; DE3034039A1; BR8005817A; LU82761A1; FR2464648A1; ZA805650B; IL61009A0

Abstract

Insecticide compositions having as an active ingredient a synthetic pyrethroid and, as a main vehicle, a vegetable oil, an unsaturated fatty acid, a polyoxyethylated fatty acid or a glyceride thereof. Other non-essential components include surfactants, alkyl aromatic solvents, U.V. stabilizers, and/or anti-oxidizers. The compositions described herein, impart to the active ingredient a greater persistance of the insecticide action and are not phytotoxic and cause very little irritating to the eyes. Generally the compositions comprise: A) 1 to 50% by weight of active ingredient, B) 30 to 80% by weight of vehicle, C) 0.5 to 20% by weight of surfactant, D) 5 to 30% by weight of solvent, E) 0 to 5% by weight of U.V. stabilizer and/or anti-oxidizer. o

Description

SPECIFICATION Liquid insecticide compositions containing synthetic pyrethroids This invention relates to liquid insecticide compositions, and in particular liquid insecticide compositions containing as an active ingredient one or more synthetic pyrethroids.

Pyrethrum is an insecticide of a natural origin, and is endowed with very positive characteristics, such as high insecticide activity and a very low toxicity for mammals. However, natural pyrethrum is readily oxidized by air in the presence of light (photooxidation) and is easily degraded, and therefore it is not suited for agricultural applications.

Numerous compounds have been synthetized, which have a slightly modified structure of natural pyrethrum, in order to preserve the insecticide action and the low toxicity to mammals, while at the same time imparting to the molecule a sufficient fastness to light, so asto allow its use in agricultural applications.

Whilst some of these compounds (synthetic pyrethorids) possess the characteristics mentioned above, the problem of the photo-oxidation has not been fully overcome and it is necessary to formulate suitable compositions that will protect the molecules as much as possible from photo-oxidation, ensuring a high persistance of the insecticide action.

Moreover, it is desirable that the insecticide compositions be non-phytotoxic and irritating to the eyes.

Conventional formulations, consisting ofthe active ingredient, an organic solvent and a surfactant, do not impart two the active ingredient a high persistance of insecticidal action and the compositions are generally irritating to the eyes.

Belgian Patent Specification No. 861,368 discloses a liquid emulsifyable formulation for synthetic pyrethroids having as a main vehicle mineral oil (white oils). This composition proved to be slightly irritating to the eyes, but did not impart to the pyrethroids a sufficiently high persistance of insecticidal action. Moreover, the mineral oils may cause phenomena of phytotoxicity, see "Pesticide Manual", 5th edition, p. 407 (1977).

It is known that some vegetable oils have a synergistic effect on the natural pyrethrines as disclosed in Pyrethrum Post, 13 (3), 82 (1976). However, in general, the effect of the synergizing products of natural pyrethrines, e.g. piperonyl butoxide, becomes practically negligible with the synthetic pyrethroids, as disclosed in "Pesticide Science", 10, p.32(1979). Experiments have confirmed that the vegetable oils also do not have a synergistic effect with the synthetic pyrethroids (see Example 10 hereinafter).

We have now found that certain vehicies selected from vegetable oils, optionally polyoxyethylated unsaturated fatty acids and polyoxyethylated glycerides, impart to the synthetic pyrethroids a high persistance to insecticidal action.

Therefore according to the invention there is provided an insecticide composition comprising: A) 1 to 50% by weight of one or more synthetic pyrethoids, B) 30 to 80% by weight of a main vehicle selected from one or more unsaturated fatty acids which may be polyoxyethylated vegetable oils, glycerides of polyoxyethylated unsaturated fatty acids, C) 0.5 to 20% by weight of surfactant, optionally D) 5 to 30% by weight of one or more alkyl aromatic solvents, and optionally E) up to 5% by weight of one or more U.V.

stabilizers and/or antioxidants.

The compositions ofthe invention possess long term insecticidal action, they are not phytotoxic and cause very littie irritation to the eyes.

Suitable synthetic pyrethroids for use in the invention include those of the general formula:

in which R' represents H, CN, -=CH, R represents

in which: R2 represents H, or a halogen atom, R3 represents H, a halogen atom, CH3 or CF3, nisOori, R' represents H, CH3, O-alkyl or O-aryl, R6 represents H, CH

,or R8-C=-C- in which: each R6 independently represent a halogen atom, each R7 independently represent a halogen atom, S-alkyl, S-aryl or CX3, in which X is a halogen atom, and R8 represents a halogen atom or CF3 Some of the synthetic pyrethroids of general formula (I) have been disclosed in "Synthetic pyrethroids", H.Elliot Editor, ACS Symposium Series No.

42, Washington 1977, Belgian Patent Specification No.858,137, German Offenlegungsschrift No. 2802 962, European Patent Specification No. 345, Belgian Patent Specification No. 863,840 and our copending Italian Patent Application Nos. 20713 A178 and 20853 At(79.

The pyrethoids used in the compositions of this invention are present in amounts of from 1 to 50% by weight. Preferably the pyrethroids are used in amounts of from 10 to 20% by weight Pure compounds ortechnical compounds are equally suitable.

The main vehicle consists of unsaturated fatty acids, optionally polyoxyethylated, vegetable oils, mono-, di- ortriglycerides of polyoxyethylated unsaturated fatty acids or by mixtures of one or more of the above mentioned components.

Suitable fatty acids include recinoleic acid, commercial oleic acid, oleine (oleic acid of high purity) and linoleic acid. Suitable vegetable oils include sunflower seed oil, olive oil, peanut oil, maise oil, linseed oil, sesame oil, castor oil, colza or rape seed oil, soya oil, hemp oil, pine oil and seed oils in general.

Examples of polyoxyethylated fatty acids or glycerides of polyoxyethylated unsaturated fatty acids include polyoxyethylated castor oil, polyoxyethylated giyceril oleate, polyoxyethylated coconut acid, polyoxyethylated oleic acid and, in general, products consisting of a polyoxyethylated unsaturated fatty acid or of glycerides of polyoxyethylated unsaturated fatty acids containing a number of moles of ethylene oxide, preferably between 5 and 50 per 1 mole of fatty acid or glyceride.

The main vehicle is present in the compositions of the invention in amounts of from 30 to 80% by weight, preferably from 50 to 80% by weight Athird component of the compositions may consist of an anionic or non-ionic surfactant. However, the presence of the surfactant is not essential when the vehicle consists at least in part of a polyoxyethylated unsaturated fatty acid or of polyoxyethylated g lycerides.

Examples of surfactants include "Emulsion 7B" consisting of polyoxyethylated nonylphenol, "Setrolene 0" consisting of polyoxyethylated sorbitan oleate, "Agrol Call" consisting of calcium alkylbenzenesulphonate, "Soprofor M52" a mixture of polyoxyethylated lauryl ether and calcium alkylbenzensulphonate (80:20) and "Setrolene S" consisting of polyoxyethylated sorbitan stearate.

The surfactant, when present, is used in the compositions of the invention in amounts of from 0.5 to 20% by weight. Concentrations of surfactant nearing the upper limit, are used when formulating a composition intended to be diluted with water, i.e. emulsifyable concentrate. Low concentrations of surfactant, are used when formulating the insecticide composition for topical application, i.e. formulations of the ultra-low volume (ULV) type.

The compositions of the invention may include other non-essential components, e.g. an alkylated aromatic solvent which may be present in amounts of from 5 to 30% by weight, in order to reduce the viscosity of the composition and to increase the sol utility of some of the pyrethroids in the main vehicle. Suitable solvents include mixtures of alkylated aromatic hydrocarbons, e.g. commercial xylol, the series of "Shellosol" solvents, the series of "Solvesso" solvents consisting of mixtures of ethyl, dimethyl and tetramethylbenzene.

U.V. stabilizers and/or antioxidants may also be included in a combined amount upto 5% by weight.

Suitable U.V. stabilizers include those belonging to the class of benzophenone derivatives and of the esters of 2,2 - diphenyl - 1 - cyano - acrylic acid (diphenylmethylidene - malonate mononitrile), specific examples of which are: 2-hydroxy-4'-octyloxy-benzophenone of the formula:

and 2-ethylhexyl ester of 1 - cyano - 2,2 - diphenyl acrylic acid of the formula:

Suitable anti-oxidants include those belonging to the class of the 2,6 - diterbutyl - phenols substituted in the 4-position offormula:

in which R may represent a wide range of groups including CH3, tert.-butyl, WH2-CH2-CO-O-C,8-H37, and

Thus, the compositions of this invention may be constituted as follows:: A) 1 to 50% by weight of active ingredient (pyrethroids), B) 30 to 80% by weight of main vehicle (unsaturated fatty acids, vegetable oils, polyoxyethylated unsaturated fatty acids, polyoxyethylated glycerides), C) 0.5 to 20% by weight of surfactant, D) 5 to 30% by weight of solvent, E) 0 to 5% by weight of U.V. stabilizer and/or antioxidizer.

Examples of suitable compositions include: A) 50% by weight of pyrethroid, and B) 50% by weight of main vehicle.

in which the main vehicle comprises a polyoxyethylated unsaturated fatty acid or a glyceride thereof.

A) 10% by weight of pyrethroid, B) 80% by weight of main vehicle, and C) 10% by weight of surfactant.

A) 10% by weight of pyrethroid, B) 65% by weight of main vehicle, C) 10% by weight of surfactant, and D) 15% by weight of solvent A) 1% by weight of pyrethroid, B) 80% by weight of main vehicle, C) 0.5% by weight of surfactant, and D) 18.5% by weight of solvent.

A) 50% by weight of pyrethroid, B) 35% by weight of main vehicle, C) 10% by weight of surfactant, and D) 5% by weight ofsolvent.

A) 20% by weight of pyrethroid, B) 50% by weight of main vehicle, C) 20% by weight of surfactant, and D) 10% by weight ofsolvent A) 10% byweightofpyrethroid, B) 63.5% by weight of main vehicle, C) 10% by weight of surfactant, D) 15% by weight of solvent, and E) 1.5% by weight of U.V. stabilizer.

A) 10% by weight of pyrethroid, B) 63% by weight of main vehicle, C) 10% by weight of surfactant, D) 15% by weight of solvent, E) 2% by weight of anti-oxidizer.

The preparation of the compositions of the invention does not require any specialist operation. Compositions having only components A, B, C and D, when present, are prepared by a simple mixing without any preferred order and at room temperature. The compositions in which component E is also present, are prepared by first dissolving component (E) in solvent (D) and by then admixing all the other components in any order.

The compositions according to this invention may be used as such, for example by the L.V. (low volume) or ULV (Ultra-low-volume) techniques or may serve as a basis for the preparation of aqueous emulsions according to conventional techniques or of aerosols by addition of suitable propellants, or may be absorbed on a solid carrier in order to prepare dusts, wettable powders or granular formulations.

The amount of composition to be used in the insecticide applications depends most of all on the relative efficacy of the particular pyrethroid used therein. The amount may depend also on the other factors such as the type of pest to be combatted, the degree of infestation, the locus of the infestation, e.g. agricultural cultivation, green house, domestic environment, the climatic and weather conditions and the mode of application. In every case the amount of composition used must be sufficient for ensuring the distribution of an insecticidally effective amount of the particular active ingredient contained in the composition.

The invention will now be illustrated by the follow ing Examples.

Example 1 10 g of 3 - phenoxy - benzyl ester of 2,2 - dimethyl 3 - (p - chloro - p - trifluoromethyl) vinyl - cyclop ropanecarboxylic acid (pyrethroid 1) were dissolved in 80 g of sunflower seed oil and then additioned with 10 g of surfactant comprising: "Emulsion 7B" 4.2 g "Setrolene 0" 2.8 g "Agrol Ca/l" 3.0 g 10.0 g Example 2 Using the same pyrethoid as in Example 1, Compositions 1 to 12, reported in the following Table I were prepared by simple admixture of the components.

Table I

Composition No.

1 2 3 4 5 6 7 8 9 1at) Z (1) 1212) 13 Component (%) Pyrethroid 1 10 10 10 10 10 10 10 10 10 10 10 10 20 Sunflower seed oil 80 Raw linseed oil 80 Olive oil 80 Castor seed oil 80 Maise oil 80 Peanut oil 80 Soya oil 80 Pine oil 80 Ethoxylated castor oil(3) 80 "RQL OB 15 (4) oil 80 "ROL OB 55(5) oil 80 "Solvesso 200" 80 Xylol 70 "Emulsion 7B" 4.2 4.2 4.2 7 : 7 7 7 7 7 "Setrolene 0" 2.8 2.8 2.8 7 7 "Agrol Call" 3 3 3 3 3 3 3 3 3 3 "Soprofor M 52" 10 10 Notes to Table I 1) Compositions according to Belgian Patent Specification No.861,368 (ICI).

2) Conventional composition with aromatic solvents.

3) Castor oil condensed with 23 moles of ethylene oxide.

4) "ROL OB 15" a mineral oil (white oil) at 97% of unsulphonable substance, viscosity equal to 2.3 E at 20 C.

5) "ROL OB 55" a white oil at 95% of unsuiphonable substance, viscosity = 29 E at 20 C.

Example 3 Evaluation of the persistance by means of the residual activity method.

The compositions subjected to the test were diluted in tap water until obtaining emulsions containing about 0.02% of pyrethroid. Castor oil plants were treated with the emulsions and then kept in the open air, under the environmental conditions of the Miianese area in May 1979.

At the times indicated in the following Table Il the leaves of the treated plants were infested in the laboratory with larvae of Spodoptera littoralis. After 48 hours from each infestation the mortality degree of the larvae was evaluated. The results are recorded on the following Table II, and are expressed as a mortality percentage.

For comparative purposes, some of the plants were besprinkled with the pyrethroid in a simple water-acetone solution (at a H2O/acetone ratio of 90:10, and a concentration of the pyrethroid of 0.02%).

From the comparison of the data reported in Table II, which relate to compositions each containing the same pyrethroid, it appears quite evident that the compositions ofthis invention impart two the pyrethroid a high persistancy, quite superior both to that imparted by the conventional compositions (Nos. 12 and 13) as well as to that imparted by compositions, Nos. 10 and 11, according to Belgian Patent Specification No.861,368.

i"ablell Residual activity on Spondoptera littoralls larvae, expressed as a mortality percentage.

Composition No. Re-infestation after days: 0 10 15 20 28 35 1 100 100 : 100 100 93 36 2 100 100 100 100 90 - 3 100 100 100 100 85 63 4 100 100 100 100 - | - 5 100 100 100 93 95 - 6 100 100 100 97 100 40 7 100 100 100 97 100 - 8 100 100 100 100 94 - 9 100 100 100 97 90 - 1011) 100 100 100 83 70 11 11(1) 100 100 100 77 73 3 100 | - | 87 | 53 | 37 | 0 100 100 100 43 23 20 0 pyrethroid in water-acetone 100 83 46 17 0 0 solution Notes to Table II A hyphen (-) means that the test has not been carried out.

(1) Composition according to Belgian Patent Specification No.

861,368.

(2) Convention composition with aromatic solvents.

Example 4 Adopting the procedures of Example 1, the compositions reported in the following Table Ill were prepared in which the pyrethroids used were: Pyrethroid 1 3-phenoxy-benzyl ester of 2,2-dimethyl-3-(sschloro-ss-trifluoromethylvinyl)-cyclopropanecarboxylic acid.

Pyrethroid 2 a - cyano - 3 - phenoxy - benzyl ester of 2,2 dimethyl - 3 - (ss - fluoro - p - trifluoromethylvinyl) cyclopropanecarboxylic acid.

Pyrethoid 3 a - cyano - 3 - phenoxy - benzyl ester of 2,2 dimethyl - 3 - (ss - trifluoromethylvinyl) - cyclopropanecarboxylic acid.

Pyrethroid 4 a - cyano - 3 - phenoxy - benzyl ester of 2,2 dimethyl - 3 - (ss - chloro - ss - methylthio - vinyl) cyclopropanecarboxylic acid.

Table III

Composition No. 14 15 16 17 17(1) 19(1) 20(1) 21(1) Component % Pyrethroid 1 10 20 Pyrethroid 2 10 20 Pyrethroid 3 10 20 Pyrethroid 4 10 20 Xylol 15 15 15 15 70 70 70 70 Sunflower seed oil 65 65 65 65 "Setrolene S" 7 7 7 7 "Emulsion 7B" 7 7 7 7 "Agrol CaUI" 3 3 3 3 3 3 3 3 1) Compositions 18 to 21 are conventional comprising pyrethroid, aromatic solvent and sur factant.

Example 5 Determination of the persistance, by means of open-airtestswith residual activity method.

The compositions subjected to test were emulsified with tap water to obtain a concentration of 0.1% of pyrethroid.

Castor oil plants were treated with these emul sions and thereafter maintained in the environmental conditions of temperature, light and humidity of the Milanese area during the month of June 1979.

The plants were periodically infested with Spodoptera littorals larvae. The percentage mortal ity rate of the larvae was evaluated after 48 hours after each infestation and the results are reported in the following Table IV.

Table IV

Composition No. Re-infestation after days: (see Example 4) 0 5 7 14 19 29 14 100 100 100 100 100 93 18 100 100 100 53 37 25 15 100 100 100 100 100 100 19 100 100 100 100 87 57 16 | 100 | 100 | 100 | 100 | 90 | 90 20 100 100 100 93 70 47 Example 6 The following additional pyrethroids were used:: Pyrethoid 5 a - cyano - 3 - phenoxy - benzyl ester of 2,2 dimethyl -3 - (p,p - dichlorovinyl) - cyclopropanecar boxylic acid (Cypermethrin).

Pyrethroid 6 3 - phenoxy - benzyl - ester of 2,2 - dimethyl - 3 (p,p - dichlorovinyl) - cyclopropanecarboxylic acid (Permethrin).

Pyrethroid 7 a - cyano - 3 - phenoxy - benzyl ester of 2,2 dimethyl -3 - (ss,ss - dibromovinyl) - cyclop ropanecarboxylic acid (Decamethrin).

Pyrethroid 8 α-cyano-3-phenoxy-benzyl ester of 2-(4 chlorophenyl) - 3 - methylbutyric acid (phenvaler ate).

Pyrethroid 9 a - cyano - 3 - phenoxy - benzyl ester of 2,2 dimethyl - 3 - (1,2 - dibromo - 2,2- dichloroethyl) cyclopropanecarboxylic acid.

The compositions reported in the following Table V were prepared. The compositions, containing U.V.

stabilizers were prepared by dissolving the latter in the organic solvent and by then adding the other components, the other compositions were prepared by simple admixture as described in Example No. 1.

Table V

Composition No. 22 23 24 26 26(1) 27 28 29(1) 30 31(1) 32 33(1) 34 35 36 37(1) 38 39 40 41 42 43 Component '%J Pyrethroid 2 10 10 10 10 1 50 20 Pyrethroid 3 10 10 Pyrethroid 5 20 10 10 Pyrethroid 6 20 10 Pyrethroid 7 5 5 Pyrethroid 8 20 10 10 10 Pyrethroid 9 20 10 Xylol 15 15 15 15 70 15 15 70 15 85 15 70 15 15 15 70 15 15 15 18.5 5 10 Sunflower seed oil 62 63.5 62 63.5 63.5 65 70 65 80 35 50 Oleic acid 65 65 65 Castor aced oil type 23 ETO(2) 63.5 65 "U.V. N-53.9"(3) 3 1.5 1.5 1.5 "Cyssorb UV 531"(4) 3 1.5 "Emulsion 7B" 7 7 7 7 7 7 7 7 7 7 10 "Setrolene S" 7 7 7 7 7 4 "Agrol Cats 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 6 "Soprofor M52" 10 10 10 10 10 0.6 Notes to Table V (1) Conventional composition comprising pyret hrnid, solvent and surfactant.

(2) Castor oil 23 ETO - polyonsyethylated castor oil containing 23 moles of ethylene oxide per mole of triglyceride.

(3) "UV N 539 - 2-ethyl-hexyl ester of 1 - cyano - 2,2 diphenyl - acrylic acid.

(4) "Cyasorb UV531"-2 - hydroxy-4-octyloxy benzophenone.

Example 7 Determination of persistance by means of green house tests with the residual activity method.

Cypermethrin (Pyrethroid No.5) a pyrethroid known to be endowed itself with a good persistance, Composition No. 26 a conventional composition consisting of Cypermethrin, alkyl aromatic solvent and surfactant and Composition No.27 a composition according to the present invention and containing Cypermethrin, were emulsified with tap water to obtain a concentration of 0.03% of pyrethroid.

A water acetone suspension of Cypermethrin (10% by volume of acetone) at the same concentration was also prepared.

Castor oil plants were treated with the above emulsion and thereafter were maintained in a green house.

The plants were periodically infested in the laboratory with Spodoptera littorals larvae. The mortality percentage of the larvae was evaluated after 48 hours from each infestation. The results are reported in the following Table VI Table VI Mortality percentage of Spodoptera littoralis larvae at the dose of 0.03%.

Composition No. Re-infestation alter days: O 2 8 hydroacetonic suspension 100 100 70 47 26 100 100 71 55 27 100 100 90 # 70 From Table VI it will be noted that the composition of the invention enhances the persistance of Cypermethrin.

Example 8 Determination of the p hytotoxicity.

The compositions reported in the following Table VII, were used to prepare aqueous emulsions at 0.4% of pyrethroid.

Table VII

Composition No Component (%) Pyrethroid 2 10 10 10 Pyrethroid 3 10 Pyrethoid 5 10 Xylol 15 15 80 15 15 Sunflower seed oil 65 65 65 "ROLoilOB15" 65 "Emulsion 7B" 7 7 7 "Setrolene S" 7 "Soporfor M52" 10 "Agrol Ca/l" 3 3 3 3 Notes to Table Vll (1) Compositions described in Example 4.

(2) Composition according to Belgian Patent Specification No.861,368.

(3) Conventional composition.

Cucumber and tomato plants were treated with these emulsions and thereafter maintained in a greenhouse under the following environmental conditions; temperature 18to 255C; period 12 hours; humidity 70%.

After seven days from the treatment, the phytotoxicity was evaluated by means of a value scale ranging from 0 (no phytotoxicity, healthy plant) to 9 (maximum phytotoxicity, completely damaged plant).

The results reported in the following Table VIII show that the compositions according to the present invention do not cause any phytotoxicity.

Table VIII Phytotoxicity of the compositions recorded on Table Vll expressed by a value scale ranging from 0 (healthy plant) to 9 (completely damaged plant).

Composition No. Dose of Phytotoxicity after 7 days pyrethroid (O/oJ Cucumber Tomato 15 0.4 0 0 44 0.4 4 2 45 0.4 3 2 16 0.4 0 0 46 0.4 0 0 Example 9 Determination of the irritation to the eyes.

The test was carried out by comparing the degree of irritation to the eyes caused by three compositions containing the same pyrethroid (Pyrethroid 2): Composition No. 15, according to the invention (Example 4); Composition No. 44, according to Belgian Patent Specification No. 861,368, and Composition No.45 of the conventional type (Example 8).

The degree of irritation was evaluated according to the J. H. Draize method disclosed in "Appraisal of the safety of chemicals in food, drugs and cosmetrics" ofthe Association of Food and Drugs Officials of the U.S.A., 46 (1959), and was expressed according to a value scale ranging from 1 (no irritation) to 8 (maximum irritation with loss of the eye).

The results, reported in the following Table IX, show that the compositions according to the invention are only very slightly irritating to the eyes and are of the same value as that of the Draize-scale assigned to the compositions according to Belgian Patent Specification No. 861,368.

Table IX Irritation to the eyes.

Composition No. Result Value according to Draize scale 16 slight irritation 2i1) 44 slight irritation 2'' 45 extremely irritating Note to Table IX (1) Reddening in the first 2 days and subsequent disappearance ofthe irritation.

(2) Since from the third day from treatment there is observed an opacity ofthe cornea which leads to the final loss of the eye.

Example 10 Demonstration of the lack of a synergistic effect of the vegetable oils added to synthetic pyrethroids.

The test was carried out by comparing the immediate insecticide activity of a pure pyrethroid in a water-acetone admixture with the activity of the same pyrethroid additioned with vegetable oils.

Test were carried out with four different vegetable oils and on three different types of insects. For this purpose, dispersions of Pyrethroid 1 (Example 1) were prepared, either alone or in admixture with vegetable oils, in a ratio of 1 :8, in water-acetone solution (H2O/acetone ratio of 9:1) to which was then added the wetting agent "Emulsion 7B" in a 0.05% concentration.

The plants or leaves suited for the tests were treated with the compositions.

a) Insecticide activity on Macrosyphum Euphorbia (aphides) Pot grown potato plants were infested with adult aphide femals and were then besprinkled with the dispersion under examination. The plants were then maintained at a temperature of 26"C, under continu ous illumination for 24 hours. At the end of that period, the insecticide activity was evaluated as a mortality percentage of aphides.

b) Biological activity on Pieris Brassicae (Lepidopt era) Cut-off cabbage leaves were besprinkled with the dispersions under examination, and subsequently were infested with Lepidoptera larvae of the same age, and then maintained at 26 C, under continuous lighting for 48 hours At the end of that period the percentage mortality of the larvae was determined.

c) Biological activity on Leptinotarsa Decemlineata Pot-grown potato plants were infested with Leptinotarsa larvae ofthe same age and subsequently were besprinkled with the dispersions under exami nation.The plants were maintained atthetempera ture of 26 C and under an uninterrupted illumination for 48 hours. At the end of that period the percentage mortality of the larvae was evaluated.

The results reported in Table X, show that the immediate insecticide activity of the pure active ingredient and that additioned with vegetable oils is equivalent and, thus, the vegetable oils do not exert any synergistic effect.

Table X

Hydroycetonic Activity on Macrosiphum E Activity on Pieris B Dispersion Oil conc. pyrethroid Mortality Oil conc. pyrethronic Mortality (%) conc.(%) % (%) conc.(%) % Pyrethroid 1 - 0.001 95 - 0.005 25 - 0.01 100 - 0.001 85 Pyrethroid 1 0.008 0.001 79 0.004 0.0005 10 Sunflower seed oil 0.08 0.01 100 0.008 0.001 60 Parethronic - 0.008 0.001 85 0.004 0.0005 30 linseed oil 0.08 0.01 100 0.008 0.001 80 Parethronic - 0.008 0.001 86 0.004 0.0005 5 olive oil 0.08 0.01 100 0.008 0.001 45 Parethronic - 0.008 0.001 81 0.004 0.0005 5 castor oil 0.08 0.01 100 0.008 0.001 45 TableX Contd.

Hydroacetonic Activity on Leptinotarsa D Dispersion Oil conc. pyrethroid Mortality (%) (%) (%) Pyrethroid 1 - 0.001 5 - 0.005 100 Pyrethroid 1 + 0.008 0.001 0 Sunflower seed oil 0.04 0.005 100 Pyrethroid + 0.008 0.001 0 linseed oil 0.04 0.005 100 Pyrethroid + 0.008 0.001 5 olive oil 0.04 0.005 100 Pyrethroid + 0.006 0.001 0 castor oil 0.04 0.005 100

Claims

1. An insecticide composition comprising: A) 1 to 50% by weight of one or more synthetic pyrethroids, B) 30 to 80% by weight of a main vehicle selected from one or more unsaturated fatty acids which may be polyoxyethylated vegetable oils, glycerides of polyoxyethylated unsaturated fatty acids, C) 0.5 to 20% by weight of surfactant, optionally (D) 5 to 30% by weight of one or more alkyl aromatic solvents, and optionally E) up to 5% by weight of one or more U.V.

stabilizers and/or anti-oxidants.

2. A composition as claimed in Claim 1, in which the pyrethroid is present in an amount from 10 to 20% by weight.

3. A composition as claimed in Claim 1 or Claim 2, in which the main vehicleis present in an amount from 50 to 80% by weight.

4. A composition as claimed in any one of claims 1 to 3, comprising: A) 10% by weight of pyrethroid, B) 80% by weight of main vehicle, and C) 10% by weight of surfactant.

5. A composition as claimed in any one of claims 1 to 3, comprising: A) 10% by weight of pyrethroid, B) 65% by weight of main vehicle, C) 10% by weight of surfactant, and D) 15% by weight of solvent

6. A composition as claimed in any one of Claims 1 to 3, comprising: A) 1% by weight of pyrethroid, B) 80% by weight of main vehicle, C) 0.5% by weight of surfactant, and D) 18.5% by weight of solvent.

7. A composition as claimed in any one of claims 1 to 3, comprising: A) 50% by weight of pyrethroid, B) 35% by weight of main vehicle, C) 10% by weight of surfactant, and D) 5% by weight of solvent

8. A composition as claimed in any one of claims 1 to 3, comprising: A) 20% by weight of pyrethroid, B) 50% by weight of main vehicle, C) 20% by weight of surfactant, and D) 10% by weight of solvent.

9. A composition as claimed in any one of claims 1 to 3, comprising: A) 10% by weight of pyrethroid, B) 63.5% by weight of main vehicle, C) 10% by weight of surfactant, D) 15% by weight of solvent, and E) 1.5% by weight of U.V. stabilizer.

10. A composition as claimed in any one of claims 1 to 3, comprising: A) 10% by weight of pyrethroid, B) 63% by weight of main vehicle, C) 100/6 by weight of surfactant, D) 15% by weight of solvent, and E) 2% by weight of anti-oxidizer.

11. A composition as claimed in any preceding claim, in which the pyrethroid has the general formula:

in which R' represents H, CN, -C=-CH, R represents

in which: R2 represents H or a halogen atom, R3 represents H, a halogen atom, CH3 or CF n is 0 or 1, R4 represents H, CH3, O-alkyl or O-aryl, R6 represents H, CH3,

or R8-C=-C-, in which: each R6 independently represent a halogen atom, each R7 independently represent a halogen atom, S-alkyl, S-aryl or CX3, in which X is a halogen atom, and R8 represents a halogen atom or CF,.

12. A composition as claimed in any one of claims 1 to 11, in which the pyrethroid is 3 - phenoxy - benzyl ester or XY - cyano - 3 - phenoxy - benzyl ester of 2,2 - dimethyl - 3 - (ss,ss - dichlorovinyl) - cyclopropanecarboxylic acid.

13. A composition as claimed in any one of claims 1 to 11, in which the pyrethroid is 3 - phenoxy - benzyl ester or α - cyano - 3 - phenoxy - benzyl ester of 2,2 - dimethyl - 3 - (,8"d - dibromovinyl) - cyclopropanecarboxylic acid.

14. A composition as claimed in any one of claims 1 to 11, in which the pyrethroid is 3 - phenoxy - benzyl ester or a - cyano - 3 - phenoxy - benzyl ester of 2,2 - dimethyl - 3 - (p - chloro - p -trifluoromethyl- vinyl) - cyclopropanecarboxylic acid.

15. A composition as claimed in any one of claims 1 to 11, in which the pyrethroid is 3 - phenoxy - benzyl ester or st - cyano - 3 - phenoxy - benzyl ester of 2,2 - dimethyl - 3 - (p - fluoro - p - trifluoromethylvinyl) - cyclopropanecarboxylic acid.

16. A composition as claimed in any one of claims 1 to 11, in which the pyrethroid is 3 - phenoxy - benzyl ester or α - cyano - 3 - phenoxy - benzyl ester of 2,2 - dimethyl - 3 - (p - trifluoromethylvinyl) - cyclopropanecarboxylic acid.

17. A composition as claimed in any one of claims 1 to 11 in which the pyrethroid is 3 - phenoxy benzyl esterora-cyano - 3 - phenoxy - benzyl ester of 2,2 - dimethyl - 3 - (p - chloro -p - methylthiovinyl) - cyclopropanecarboxylic acid.

18. A composition as claimed in any one of claims 1 to 11 in which the pyrethroid is 3 - phenoxy benzyl ester or a - cyano - 3 - phenoxy - benzyl ester of 2,2 - dimethyl - 3 - (2,2, - dichloro - 1,2 - dibromo ethyl) - cyclopropanecarboxylic acid.

19. A composition as claimed in any one of claims 1 to 11 in which the pyrethroid is 3 - phenoxy benzyl ester or a - cyano - 3 - phenoxy - benzyl ester of a - (4 - chloro - phenyl) - p - methyl - butyric acid.

20. A composition as claimed in any one of claims 1 to 11, in which the pyrethroid is 3 - phenoxy - benzyl ester or a - cyano - 3 - phenoxy - benzyl ester of a - (2 - chloro -4-trifluoromethyl - phenyl - amino) - ss - methyl - butyric acid.

21. A composition as claimed in any preceding claim, in which the main vehicle is either an unsaturated fatty acid or a mixture of unsaturated fatty acids.

22. A composition as claimed in any one of claims 1 to 20, in which the main vehicle is a vegetable oil or a mixture of vegetable oils.

23. A composition as claimed in any one of claims 1 to 20, in which the main vehicle is a polyoxyethylated unsaturated fatty acid or a mixture of polyoxyethylated unsaturated fatty acids.

24. A composition as claimed in any one of claims 1 to 20 in which the main vehicle is a mixture of polyoxyethylated glycerides of unsaturated fatty acids.

25. A composition as claimed in any preceding claim, in which the surfactant consists of alkylbenzenesulphonates, alkytphenolpolyoxyethylated, polyoxyethylated sorbitan oleate or sorbitan stearate or any combination thereof.

26. A composition as claimed in any preceding claim, in which the solvent consists oftoluene, xylene, ethylbenzene, trimethylbenzene, tetramethylbenzene or any combination thereof.

27. A composition as claimed in any preceding claim in which the U.V. stabilizer is a derivative of 2 hydroxy - 4. alkoxy - benzophenone or a 2,2diphenyl - 1 - cyano - acrylic ester.

28. A composition as claimed in any preceding claim, in which the antioxidizer is a derivative of 2,6 di-terbutyl-phenol.

29. A modified composition of Claim 1 in which the main vehicle comprises a polyoxyethylated unsaturated fatty acid or a glyceride thereof, said composition comprising: 50% by weight of pyrethroid, and 50% by weight of main vehicle.

30. An insecticide composition as claimed in Claim 1, substantially as herein described with reference to any one of the Examples.

31. An emulsion in waterformed from a composition as claimed in any preceding claim.

32. A dust, wettable powder, or granular formulation formed from a composition as claimed in any one of claims 1 to 30.

33. A method of cornbatting infestations by insects comprising contacting the infested area with a composition as claimed in any preceding claim.