GB2151926A - Pesticidal composition containing pyrethroids - Google Patents

Abstract

A pesticide composition contains a mixture of a pyrethroid-type compound of the general formula I <IMAGE> wherein R1 is a hydrogen atom and R2 is a 2-methyl-1-propenyl group, or R1 and R2 are each a methyl group; and 2,3,4,5,6-pentafluorobenzyl 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate. The composition demonstrates an excellent synergistic effect, especially in use as a non-heating fumigating composition.

Description

SPECIFICATION Pesticidal composition This invention relates to a pesticidal composition, and more specifically, to a fumigating pesticidal composition containing a mixture of a pyrethroid-type compound of general formula [I] below and 2,3,4,5,6-pentafluorobenzyl 2,2-dimethyl-3-(2,2-dichlorovinyl)-cyclopropanecarboxylate.

wherein R1 is a hydrogen atom or a methyl group, and R2 is a 2-methyl-1-propenyl group when R1 represents a hydrogen atom and a methyl group when R1 represents a methyl group.

Recently, pyrethroid-type compounds have come to be used as insecticide for insects harmful to clothes instead of subliming materials such as camphor and paradichlorobenzene.

However, even such compounds do not have sufficient long term effect. In these compounds, long term residual effect is desired in addition to high initial efficacy because of the purpose of use.

After various investigations for preparing a fumigating composition serving such purposes, these inventors have found that a composition obtained by mixing a pyrethroid-type compound of general formula [I] above and 2,3,4,5,6-pentafluorobenzyl 2,2-dimethyl-3-(2,2-dichlorovinyl)- cyclopropanecarboxylate (hereinafter referred to as compound A), especially a composition prepared by mixing a pyrethroid-type compound of general formual [I] and compound A in a ratio of form 1:1 to 4:1 by weight, is excellent as the active ingredient of a fumigating pesticidal composition, in particular non-heating fumigating composition, which has high initial efficacy and long term residual effect resulting from the synergistic effect and volatility thereof.

In the composition of this invention, as the pyrethroid-type compound of general formula [I], (t)-l-ethynyl-2-methyl-2-pentenyl (+)-cis, trans-chrysanthemate (compound (1)), (+)-1-ethynyl-2-methyl-2- pntenyl (+ )-cis,trans-chrysanthemate (compound (2)), )-I-ethynyl-2-methyl-2-pentenyl (+ )4rans- chrysanthemate (compound (3)), (+ )-l-ethynyl-2-methyl-2-pentenyl (+)-cis,trans-chrysanthemate (compound (4)), (t-)-l-ethynyl-2-methyl-2-pentenyl (+ )-trans-chrysanthemate (compound (5)), (-t)-l-ethynyl-2- methyl-2-pentenyl 2,2,3,3-tetramethyl-cyclopropanecarboxylate (compound (6)) and (+ )-1 -ethynyl-2-methyl- 2-pentenyl 2,2,3,3-tetramethylcyclopropanecarboxylate (compound (7)) are listed.

As compound A, various pyrethroid-type compounds such as 2,3,4,5,6-pentafluorobenzyl ()-cis,trans-2,2- dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate (compound (8)) and 2,3,4,5,6-pentafluorobenzyl (+) trans-2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate (compound (9)) as well as their optical isomers, stereoisomers and mixtures thereof are listed.

Among these compounds, the following combinations are preferable as the active ingredient in the pesticidal composition of this invention from the viewpoint of the practical use and availability of materials, etc.

A combination of compound (2) with compound (8) or (9).

A combination of compound (3) with compound (9).

A combination of compound (4) with compound (9).

A combination of compound (5) with compound (9).

A combination of compound (6) with compound (8) or (9).

A combination of compound (7) with compound (9).

In the following, the excellent properties of the composition of this invention as an active ingredient for a pesticide will be explained according to examples.

sample 1 Each of acetone solutions containing compound (2) alone, compound (8) alone, compound (9) alone or mixtures thereof indicated in Table 1 below was dropped onto filter paper of 10 x 10 cm to be impregnated with a given quantity of the active ingredient.

The thus prepared filter paper impregnated with the active ingredient was set under aeration condition at room temperature (25"C) and the amount of the active ingredient volatilized in five days was calculated by determining the content of the active ingredient remaining in the tested filter paper by analyzing the extract of tested filter paper by gas chromatography. The results are shown in Table 1.

TABLE 1 Set Content Content Content Speed of Com- quantity immediately remaining volatilized Volatilization pound (mgl100cm2) after after during5days (mgiday) No. preparation 5 days {Calculation* (Analyzed (mug)) (Analyzed (mug)) (mug)) (2) 20 19.902 6.628 13.274 2.65 (8) 20 20.064 16.974 3.090 0.618 (8) 10 10.012 7.351 2.661 0.532 (8) 5 4.927 3.344 1.583 0.317 (2) 20 19.554 12.809 6.745 1.35 + (8) 20 19.605 17.209 2.396 0.479 (2) 20 19.823 9.013 10.810 2.16 + (8) 10 10.011 8.288 1.723 0.345 (2) 20 19.422 9.719 9.703 1.94 + (8) 5 4.643 3.758 0.885 0.177 (9) 10 10.053 7.480 2.573 0.515 (2) 20 19.655 8.702 10.953 2.19 + (9) 10 10.020 8.396 1.624 0.325 * Calculation = Content of the active ingredient Content of the active ingredient (mg) immediately after the preparation - remaining after 5 days (Analyzed (mg)) (Analyzed (mg)) As clearly seen from Table 1 above, the composition of this invention, because of having a high volatility in a long term not only in the initial stage, has excellent characteristics as a pesticidal composition, in particular when used in the form of non-heating fumigant.

The composition of this invention, because of its characteristics, is primarily used to exterminate pests of clothes, human bodies and stored grain. It is especially suitable for exterminating insects harmful to clothes.

In the pesticidal composition of this invention, the mixtures of active ingredients may be formulated, according to procedures throughly known to those skilled in the art using various adsorption carrier such as mothproofing paper, resin, ceramic, asbestos, glass wool, pulp and nonwoven fabric into various forms of compositions to be put to practical use.

In the composition of this invention, the active ingredients are contained in an amount of 0.01 to 90% by weight.

The compositions of the present invention may contain such synergists for pyrethroids as butoxyethoxy)ethoxy]-4,5-methylenedioxy-2-prnpyltol uene (hereinafter referred to as "piperonyl butoxide"), N-(2-ethylhexyl)bicyclo[2,2,1 Jhepta-5-ene-2,3-dicarboximide (hereinafter referred to as "MGK-264") and octachlorodipropyl ether (hereinafter referred to as "S-421"), or other known synergists effective for allethrin and pyrethrin.

Generally, chrysanthemic acid ester type compounds are somewhat low in stability to light, heat and oxidation. Accordingly, when antioxidants or ultraviolet absorbers, e.g. phenol derivatives such as BHT (butylated hydroxytoluene), bisphenol derivatives, arylamines such as phenyl-cr-naphthylamine, phenyl-t3- naphthylamine or a condensation product between phenetidine and acetone or benzophenone type compounds are added in suitable amounts as stabilizers to the composition of the present invention, it is possible to obtain compositions which have been more stabilized in pesticidal effectiveness. As to the names of compounds used as the above antioxidant, 2,6-di-tert-butyl-4-methylphenol, 2,2'-methylenbis(6-tert- butyl-4-methylphenol), 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), 4,4'-methylenebis(2,6-di-tert- butylphenol), 4,4'-butylidenebis(6-tert-butyl-3-methylphenol) and 4,4'-thiobis(6-tert-butyl-3-methylphenol) are listed.

The preparation of the composition of this invention will be explained according to Formulation Examples in the following. But this invention is not restricted to the following examples.

Formulation Example 1 Each of mixture consisting of 0.5 g compound (1), (2), (3) or (6) and 0.3 g compound (8) or (9), as it is or after being dissolved in an organic solvent, was caused to be homogeneously adsorbed by filter paper of 10 x 15 cm, and then inserted in a case made of plastics or pasteboard or in a bag made of Japanese paper or nonwoven cloth, thereby obtaining each fumigating composition. The above adsorption procedure can be carried out by a dropping method, immersion method or gravure printing method. And a small quantity of perfume or the like may be added into these compositions. As a material for the adsorption carrier, glass wool, asbestos, resin, ceramics and nonwoven cloth having similar properties can be used in addition to a pulp material such as filter paper.

Formulation Example 2 Each of mixture consisting of 0.3 g compound (2), (4) or (7) and 0.2 g compound (8) or (9) was subjected to the same procedure as Formulation Example 1 above, thereby obtaining each fumigating composition.

Formulation Example 3 Each of mixture consisting of 0.4 g compound (2), (5) or (7) and 0.1 g compound (8) or (9) was subjected to the same procedure as Formulation Example 1 above, thereby obtaining each fumigating composition.

Formulation Example 4 After each of mixture consisting of 0.3 g compound (2) and 0.3 g compound (9) and mixture consisting of 0.4 g compound (2) and 0.2 g compound (9) was dissolved in 5 ml of acetone, the solution was caused to be homogeneously absorbed by filter paper of 10 x 15 cm, thereby obtaining fumigating compositions.

Example 2 Six articles of clothing were put in each of two 0.7 m3 steel cabinets. Two pieces each of paper impregnated with the mixture of 0.3 g of compound (2) and 0.3 g of compound (9) (this paper referred to as "Paper 0") and paper impregnated with the mixture of 0.4 g of compound (2) and 0.2 g of compound (9) (this paper referred to as "Paper Q"), which were prepared according to Formulation Example 4, were suspended from positions of the ceiling corresponding to the second clothing from the right and the left ends (two pieces/cabinet).

After given days, three spherical wire net cages of 4 cm diameter each containing 20 larvae of casemaking clothes moth (Tinae pellionella Linne) and a wool fabric of 2 x 2 cm were placed between the first and the second clothing from the right and the left ends as well as between the center two articles of clothing in the cabinet. Following that the number of dead larvae of casemaking clothes moth during one week was counted so as to obtain the mortality. The results are as shown in Table 2.

TABLE 2 Elapsing Mortality ofcasemaking clothes moth with oftime elapsing of time {%) (weeks) "papers" "papers" Left Center Right Left Center Right 1-2 100 100 100 100 100 100 4-5 100 100 100 100 100 100 8-9 100 100 100 100 100 100 As clearly seen from Table 2 above, the composition of this invention possesses a high insecticidal activity on insects harmful to clothes for long term.

Example 3 Papers impregnated with a mixture of 0.4 g of compound (2) and 0.1 g of compound (8) was prepared according to Formulation Example 4. In the same manner, papers inpregnated with 0.5 g of compound (2) alone and papers impregnated with 0.5 g of compound (8) alone were prepared for using in comparative test. Following that, the insecticidal efficacy of these papers on female adults of northern house mosquitos (Culexpipienspallens) was evaluated at room temperature with elapsing of time according to the procedure described below.

In this test, in order to avoid contact between the said paper and tested insects, the paper was used after being inserted in a nylon net cage of 12 cm inner diameter and 20 cm height.

1 ) Test for determining the initial efficacy Each of above papers being inserted in a nylon net cage immedately afterthe preparation was suspended from the center of the ceiling of a glass box of 0.34 m3 capacity (70 x 70 x 70 cm). 50 Female adults of northern house mosquitos were released into the box and then the number of knocked down insects were counted with elapsing of time. KT50 values (time required to knock down 50% of tested insects) were obtained by the conventional method from the results of these experiments.

2) Test for determining the long-term efficacy (efficacy with elapsing of timer KT50 values of each paper used in the above test for determining the initial efficacy were obtained after leaving it to stand at room temperature for three days, one week and two weeks from the day of its preparation by the same method as described above.

The results are shown in Table 3.

TABLE 3

Active ingredient KT50 (minutes) with Elapsing the content of time thereof On the day of prepara- 3 days 'week 2 weeks tion after after after (initial efficacy) Compound (2) 0.4g + 70 55 48 114 | Compound | (8) 0.1g (2) 0.5g Compound 91 97 102 160 (8) 0.5g Example 4 Papers impregnated with a mixture of 0.4 g of compound (2) and 0.1 g of compound (9) were prepared according to Formulation Example 4. In the same manner, papers impregnated with 0.5 g of compound (2) alone and papers impregnated with 0.5 g of compound (9) alone were prepared for using comparative test.

Following that, the insecticidal efficacy of these papers on adults of houseflies (Musca domestica) were evaluated in the same manner as Example 3.

The results are shown in Table 4.

TABLE 4

Active KT50 (minutes) with Elapsing ingredient oftime and content thereof On the day ofprepara- 3 days iweek 2 weeks tion after after after (initial efficacy) Compound (2) 0.4 g + 15 14 20 51 Compound (g) 0.1 g Compound 14 15 24 222 (2) 0.5g Compound 24 25 27 84 (9) 0.5g

Claims (11)

1. A pesticidal composition characterized in that said composition contains a mixture of a pyrethroidtype compound of general formula [I],

wherein R1 represents a hydrogen atom or a methyl group, and R2 represents a 2-methyl-1-propenyl group when R1 represents a hydrogen atom and a methyl group when R1 represents a methyl group; and 2,3,4,5,6-pentafluorobenzyl 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate.

2. The pesticidal composition according to Claim 1,wherein the mixture is a mixture of a pyrethroid-type compound of formula [I] and 2,3,4,5,6-pentafluorobenzyl 2,2-dimethyl-3-(2,2dichlorovinyl)cyclopropanecarboxylate in a ratio of from 1:1 to 4:1 by weight.

3. The pesticidal composition according to Claim 1 or 2, wherein the composition is a non-heating fumigating composition.

4. The pesticidal composition according to Claim 3, wherein the composition is an insecticidal composition for exterminating insects harmful to clothes.

5. The pesticidal composition according to any preceding Claim, wherein the mixture is a mixture of (+)-1-ethynyl-2-methyl-2-pentenyl (+)-cis,trans-chrysanthemate and 2,3,4,5,6-pentafluorobenzyl (t)- cis,trans-2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate or 2,3,4,5,6-pentafluorobenzyl (+) trans-2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate.

6. The pesticidal composition according to any of Claims 1 to 4, wherein the mixture is a mixture of (+ )-1 -ethynyl-2-methyl-2-pentenyl (+ )-trans-chrysanthemate and 2,3,4,5,6-pentafl uorobenzyl (+ )-trans-2,2- dimethyl-3-(2,2,-dichlorovinyl)cyclopropanecarboxylate.

7. The pesticidal composition according to any of Claims 1 to 4, wherein the mixture is a mixture of (+ )-1 -ethynyl-2-methyl-2-pentenyl (+ )-cis,trans-chrysanthemate and 2,3,4,5,6-pentafluorobenzyl (+ )-trans- 2,2-dimethyl-3-(2,2,-dichlorovinyl)cyclopropanecarboxylate.

8. The pesticidal composition according to any of Claims 1 to 4, wherein the mixture is a mixture of ( + )-1 -ethynyl-2-methyl-2-pentenyl (t)-trans-chrysanthemate and 2,3,4,5,6-pentafluorobenzyl (+ )-trans-2,2- dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate.

9. The pesticidal composition according to any of Claims 1 to 4, wherein the mixture is a mixture of (t )-1 -ethynyl-2-methyl-2-pentenyl 2,2,3,3-tetramethylcyclopropanecarboxylate and 2,3,4,5,6- pentafluorobenzyl ()-cisArans-2,2-dimethyl-3-(2,2-dichlornvinyl)cycloprnpanecarboxylate or 2,3,4,5,6pentafluorobenzyl (+)-trans-2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate.

10. The pesticidal composition according to any of Claims 1 to 4, wherein the mixture is a mixture of (+ )-1 -ethynyl-2-methyl-2-pentenyl 2,2,3,3,-tetramethylcyclopropanecarboxylate and 2,3,4,5,6pentafluorobenzyl (+ )-trans-2-2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate.

11. A pesticidal composition according to any preceding Claim, which is substantially as herein described and exemplified.