GB2225719A - Method for controlling insects and/or acarines by mild heating of a pyrethroid - Google Patents

Description

j i METHOD FOR CONTROLLING INSECTS AND/OR ACARINES 1 The present invention

relates to a method for controlling insects and/or acarines which comprises vaporizing an active ingredient by mildly heating the same.

Although various methods for controlling insects and/or acarines are known today, such a method comprising vaporizing a pyrethroid compound by mildly heating the same is relatively unknown. An isolated instance for such a method is the method with 1-ethynyl- 2-methyl-2-pentenyl chrysanthemate disclosed in JP-A-5675411.

However, unless used in a considerably large amount, 1-ethynyl-2-methyl-2pentenyl chrysanthemate is not necessarily effective in controlling pests especial- ly in a wide space such as room, storage chamber, closetr warehouse, vehicler ship, airplane, store, cattle shed, stable, drainage trench, sewer, etc. Also for duration of the effect for a long period of time, this agent should be used in a large amount.

Vaporization of an active ingredient by intensely heating is sometimes effective in enhancing the initial efficacy. But, saving in energy is required for protecting the earth environment. If an active ingredient can be vaporized using surplus or unutilized heat generated by a heating appliance, a lighting -1 t 1 appliance, etc., it will become possible to save precious energy.

There is a method comprising burning a carrier for vaporizing an active agent as in, for example, mosquito coil. Needless to say, according to a method comprising vaporizing an active ingredient by the use of surplus or unutilized heat generated by a heating appliance, a lighting appliance, etc., it is also possible to prevent fuming, burning and fire which might occur by the method comprising burning a carrier.

According to the present invention, there is provided a method for controlling insects and/or acarines comprising vaporizing 1-ethynyl-2methyl-2pentenyl 3-(2f2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate (hereinafter Compound I) having the formula, C 2 115 C=C /CH3 0 CH==2 H CH-O-i-CH-CH C C C H3C C113 H [I] by mildly heating the same.

The present inventors earnestly investigated a method for effectively controlling insects and/or acarines comprising vaporizing an active ingredient by mild heating, and consequently found that out of numerous well!--known insecticidal and acaricidal agents, Compound I is the most suitable for the object of the present invention, whereby the present invention was accomplished.

It has been disclosed in JP-B-55-42045 that Compound I has an insecticidal and acaricidal activity. The present inventors, however, found that mere vaporization of said compound by mild heating has a high. initial activity against insects and/or acarines and that the activity lasts for a long period of time, whereby the present inventors were led to the present invention.

The term "mild heating" used herein means heating at a temperature not higher than about 1000C but higher than 500C. Such heating can easily be obtained using surplus or unutilized heat generated by a chemical heat generator such as pocket heater, or a heating element such as electric heater.

The method of the present invention is effective against various insect pests and acarine pests. It is markedly effective against hygienic pests, wood pests, food stuff pests, household nuisance pests, etc. Particularlyr it is most effective against hygienic pests and household nuisance pests.

Specific examples of insect pests and acarine 2.5 pests to which the method of the present invention can be applied are given below.

a c Lepidoptera Plodia interpunctella (Indian meal moth), etc. Diptera Culex spp. (common mosquitoes). Anopheles spp. (Anopheline mosquitoes), Aedes spp., Muscidae (house flies), Drosophilidae (wine flies), Psychodidae (moth flies), Chironomidae (chironomid midges), Calliphoridae (blow flies), Sarcophagidae ( flesh flies), Simuli idae (black flies)# Tabaridae (tabanid flies), Stomoxyidae (stable flies), etc.

Coleoptera Sitophilus zeamais (maize weevil), Callosobruchus chinensis (adzuki bean weevil), Tribolium castaneum (red flour beetle)r Anobiidae (deathwatch and drugstore beetles)r Lyctidae (powder post beetles), Paederus fuscipes (robe beetle) etc.

Dictyoptera Blattella qermanica (German cockroach), Periplaneta fuliqinosa- (smokybrown cockroach), Periplaneta americana (American cockroach), Periplaneta brunnea (brown cockroach), Blatta orientalis (oriental cockroach), etc. Hymenoptera Formicidae (ants), Bethylidae (bethylid wasps), etc. Siphonaptera Pulex irritans, et c Anoplura Pediculus humanus capitis (body louse), Pthirus]2ubis (crab louse), etc.

Isoptera Reticulitermes speratus, Coptotermes formosanus (Formosan subterranean termite), etc.

Acarina Mites associated with house dust and stored food, such as Acaridae, Pyroglyphidae, Cheyletidae, and the like, Ixodidae such as Boophilus microplusr and the like, Dermanyssidae, etc.

For controlling insects and/or acarines by vaporizing Compound I, a carrier is not always necessary. Usually, however, Compound I is used after being supported on a suitable carrier.

Specific examples of carrier for adsorption used for this purpose are papers such as filter paper, cardboard and the like; pulp; resins such as polyethylene, polypropylene, vinyl chloride and the like; ceramics; asbestos; glass fiber; carbon fiber; chemical fibers; natural fibers; nonwoven fabrics; porous polymer films; porous glass materials; porous absorbent wicks; substrates for electric fumigating mat (a plate formed of fibril of a mixture of cotton linter and pulp); diatomaceous earth; etc. These carriers which have Compound I supported thereon can be used in any preparation form.

The vaporizing efficiency can be further 1 1 increased by adding subliming materials such as adamantane, cyclododecane, trimethylnorbornane, etc., as adjuvant for promoting the vaporization.

It is also possible to enhance the efficacy by using Compound I in admixture with known synergists effective for allethrin and pyrethrins, etc., specific examples of which being synergists for pyrethroid such as a-[2-(2-butoxyethoxy)ethoxy]-4,5-methylenedioxy-2propyltoluene (piperonyl butoxide), N-(2-ethylhexyl)- bicyclo[2,2,ljhepta-5-ene-2,3-dicarboxyimide (MGK-2640), octachlorodiisopropyl ether (S-4210), Synepirin-5000, etc.

The efficacy of Compound I can be stabilized by using Compound I as a blend with an antioxidant and an ultraviolet absorber for increasing the stability to light, heat, oxidation, etc. Specific examples of the antioxidant are 2,21-methylenebis(6-tert-butyl-4ethylphenol)r 2r6-di-tertbutyl-4-methylphenol (BHT), 2,6-di-tert-butylphenol. 2,2'-methylenebis(6tert-butyl- 4-methylphenol), 4.41-methylenebis(2,6-di-tertbutylphenol).r 4r41- butylidenebis(6 tert-butyl-3-methylphenol), 4,41-thiobis(6-tert-butyl-3- methylphenol), and dibutylhydroquinone (DBH). The specific examples of the ultraviolet absorber are phenol derivatives such as BHT, bisphenol derivatives, arylamines such as condensation products between phenyl-a-naphthylamine, phenyl-pnaphthylamine or phenetidine and acetone, and benzophenone compounds.

1 1 i I Compound I may be used in admixture with dyes such as allylaminoanthraquinone, 1,4-diisopropylaminoanthraquinone, 1,4diaminoanthraquinone, 1,4-dibutylaminoanthraquinone, I-amino-4anilinoanthraquinone and the like, and perfumes for vaporizable composition.

In supporting Compound I on a carrier, there can, if necessary, be used additives such as fatty acid esters (e.g., isopropyl myristate, isopropyl palmitate and hexyl laurate), and organic solvents (e.g. isopropyl alcohol and deodorized kerosine) in order to lower the viscosity and facilitate impregnation.

The carrier having Compound I supported thereon which is obtained in the manner described above can be used by vaporizing compound I by mild heating. It exhibits a high insecticidal and/or acaricidal activity when placed particularly in a relatively closed place, for example, room, storage chamber, closet, warehouse, vehicle, ship, airplane, storer cattle shed, stable, drainage trench, sewer, etc. It permits sufficiently effective control of insects and/or acarines even when placed in an opener place, for example, the outdoors.

For heating the carrier having Compound I supported thereon, there can be utilized surplus or unutilized heat generated by a petroleum benzine pocket heater, a chemically heat-generating pocket heaterr a heating element (e. g. a heater) adjusted to a heating temperature of 500 to 100C, a lighting appliance (e.g. an electric lamp such as incandescent lamp or fluores- - 8 1 cent lamp, o r a kerosene lamp). Usually, in a conventional method a ccuinercially available, electric heater for mosquito mat is heated at about 1600C, or a commercially available heater for an insecticidal device in which a part of a porous absorbent wick is immersed in an insecticidal liquid to absorb the insecticidal liquid and its upper part is heated) is heated at approximately 1300 1600C. These devices can also be used in the method of the present invention by proper modification of the electric resistance, the material for the heat-generating part, adjustment of the thermostat, etc.

Specific examples of the application method using a heating element are a method comprising making a carrier into a mat having a suitable size for a heating element, having Compound I supported on the mat and placing the resulting mat on the heating element, and a method using a device, such as the above wick device, in which a mat is not employed.

As a method utilizing surplus or unutilized heat generated by a pocket heater utilizing the heat of a chemical reaction, there may be exemplified a method comprising incorporating Compound I into a heatgenerating agent, and a method comprising supporting Compound I on a wrapping material outside a heat generator.

Specific examples of methods utilizing unutilized heat generated by a lighting appliance (e.g. an electric lamp such as incandescent lamp or fluorescent lamp, or a kerosene lamp) are a method comprising 1 9 - k 1 coating Compound I on the glass surface of a lamp or a part of a lighting appliance and utilizing heat conducted or emitted by the lamp, and a method comprising placing a carrier having Compound I supported thereon on or near the glass surface of a lamp and utilizing heat conducted or emitted by the lamp.

In the method of the present invention, the application rate of Compound I is not critical. It should be determined in view of many factors such as the concentration of Compound I, type of preparations, manner and timing of application, environmental temperature and humidity, space to be applied and the width thereof, whether the space is open or not, whether natural or artificial air streams go through the space or not, kind of insects or acarines to be controlled, habitat of insects or acarines, etc. However, Compound I is usually applied in a ratio of from 0.1 Mg/m3 to 50 g/M3, preferably I mg/M3 to 2 g/M3. This is only a rough standard and Compound I may be applied beyond the range as occasion demands.

Fo.rming an air stream by stirring the air by artificial wind from a motorized fan (e.g. an electric fan) or from an air-conditioner or by natural wind may encourage the insecticidal and/or acaricidal efficacy of 25. the method of the present invention so as to enable to apply the method in a wider space.

Compound I can be prepared according to the process disclosed in JP-B-5542045, for example.

1 Compound I has optical isomers due to the asymmetric carbon atoms in the alcohol moiety and the acid moiety. It also has geometrical isomers due to the cyclopropane ring in the acid moiety. Some of them are shown in Table 1. Of the isomers, Compounds [I]- A, [I]B and (II-C are more active than the other isomers.

Table 1

Symbol of Configuration of Configuration of compound the alcohol the acid moiety moiety [I]-A S 1R-trans [I]-B S 1RS-trans [II-C RS 1R-trans [I]-D RS 1RS-cis [I]-E RS 1RS-cis,trans The following reference example, preparation examples and test examples serve to give specific illustration of the present invention but they are not intended in any way to limit the scope of the present invention.

Reference Example Compound [I]-A was prepared as follows:

0.50 Grams of (1S)-1-ethynyl-2-methyl-2- pentenol (described in JP-B-63-52615) was dissolved in dry toluene, and 0. 50 9 of pyridine was added thereto.

1 1 To the resulting solution was added 0.90 g of (1R) trans-3-(2,2dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic acid chloride (the corresponding carboxylic acid is described in JP-A-62-253398. for example). The resulting solution was stirred overnight at room temperature. The reaction mixture, after water had been added thereto, was extracted with toluene. The organic layer was washed successively with dilute aqueous hydrochloric acid, saturated aqueous solution of sodium 10 hydrogen carbonate and saturated aqueous sodium chloride. Thereafter, the layer was dried over anhydrous sodium sulfate. The dried layer was filtered and concentrated to obtain a residue. Purifying the residue with silica gel chromatography (eluent: a 10:1 is mixture of hexane and ethyl acetate) gave 1.05 g of (1S)-1-ethynyl-2-methyl-2-pentenyl (1R)-trans-3-(2, 2dichloroethenyl)-2,2-dimethylcyclopropanecarboxYlate (Compound [I]-A) in a yield of 83%.

20.5 n D 1.5063 [CL] 24: -7.20 (dimethyl ether, C = 0.53) D Preparation Example 1 In an adequate amount of acetone was dissolved mg of Compound I, and a pulp plate having an area of 4 cm square and a thickness of 0.14 cm was impregnated with the resulting solution. Air-drying the plate to remove acetone therefrom gave a composition capable of vaporizing the active ingredient with mild heating - 12 (hereinafter a mild-heating type vaporizable preparation). Fixing this preparation on the surface of a petroleum benzine pocket heater capable of generating heat of 500 to 700C gave a mild-heating type insecticidal and/or acaricidal device.

Preparation Example 2 In an adequate amount of acetone were dissolved 50 mg of Compound I and 20 mg of BHT, and one side of a nonwoven fabric was impregnated with the resulting solution. Air-drying the nonwoven fabric to remove acetone gave a mild-heating type vaporizable preparation. Using this preparation as an outermost bag of a heat generator capable of generating heat of 500 to 700C gave a mild-heating type insecticidal and/or acaricidal device.

Preparation Example 3 In an adequate amount of hexane were dissolved 80 mg of Compound 1, 40 mg of octachlorodiisopropyl ether and 30 mg of BHT. Impregnating a pulp plate having an area of 3 cm square and a thickness of 0.1 cm with the resulting solution gave a mild-heating type vaporizable preparation. Attaching this preparation to one side of a pocket heater capable of generating heat of 50 to 70C gave a mild-heating type insecticidal and/or acaridical device.

Preparation Example 4 A substrate for electric fumigating mat was prepared by pressing fibrils of a mixture of cotton linter and pulp into a plate having an area of 2.5 cm x 5 1.5 cm and a thickness of 0.3 cm.

In acetone were'dissolved 0.4 g of Compound I and 0.2 g of piperonyl butoxide to make a total volume of 10 ml. Then, the above-prepared mat was uniformly impregnated with 0.5 ml of the resulting solution to obtain a mild-heating type vaporizable preparation. Fixing this preparation to a heater for electric mat whose heater part was capable of generating heat of 500 to 1000C gave a mild-heating type insecticidal and/or acaricidal device.

Preparation Example 5 In 10 ml of deodorized kerosene was dissolved 100 mg of Compound I to obtain an insecticidal solution. The solution was placed in a container. One end of porous absorbent wick having a diameter of 0.9 cm and a length of 7 cm was immersed in the solution and the other end was fixed at the mouth of the container, whereby a mild-heating type vaporizable preparation was obtained. A heater for a porous wick device which was capable of generating heat of 800 to 1000C was fixed at the mouth of the container so as to make it possible to heat the upper end of the wick fixed at the mouth of the container. Thus, a mild-heating type insecticidal 1 and/or acaricidal device was obtained.

Preparation Example 6 A solution was prepared by uniformly mixing 50 mg of Compound 1, 10 mg of 2j21-methylenebis(6-tertbutyl-4-ethylphenol), 25 mg of isopropyl myristate and 65 mg of kerosene-. Uniformly impregnating a substrate for electric fumigating mat having a size of 2.5 cm x 1.5 cm and a thickness of 0.11 cm (a plate formed of fibril of a mixture of cotton linter and pulp) with this solution gave a mild-heating type vaporizable preparation. Fixing the mat to a heater for electric mat whose heater part was capable of generating heat of 500 to 1000C gave a mild-heating type insecticidal'and/or acaricidal device.

Preparation Example 7 A transparent vinyl chloride sheet having an area of 50 cm x 9 cm and a thickness of 0.2 cm and containing 500 mg of Compound I uniformly (-a mildheating type vaporizable preparation) is wound round and fixed on the surface of a domestic fluorescent lamp (100 V, 20 W). When the lamp is attached to a domestic fluorescent lighting appliance and an electric current is passed through the lampr the vinyl chloride sheet is heated by the unutilized heat and functions as a mildheating type insecticidal and/or acaricidal device.

S 1 1 Preparation Example 8 Into 2 g of diatomaceous earth is infiltrated 0.1 g of Compound I and 0. 05 g of BHT to obtain a mildheating type vaporizable preparation. The diatomaceous earth is uniformly incorporated into a heat-generating agent designed to generate heat of 500 to 1000C by utilization of the heat of oxidation. The resulting heat-generating agent is put into a bag made of Japanese paper, whereby a pocket heater having an insecticidal and/or acaricidal function is obtained.

Preparation Example 9 In an adequate amount of acetone are dissolved 50 mg of Compound 1, 10 mg of piperonyl butoxide and 50 mg of dibuty1hydroquinone. A nonwoven fabric is impreg- nated with the resulting solution from one side. Airdrying the nonwoven fabric to remove acetone therefrom gave a mild-heating type vaporizable preparation. An inner bag is made of the thus treated nonwoven fabric and into the inner bag is packed a heat-generating agent designed to generate heat of 700 to 1000C by utilization of the heat of oxidation. Covering the outside of the inner bag with a bag made of cotton gave a pocket heater having an insecticidal and/or acaridical function.

In the following test examples, the members tested of Compound I are indicated by the symbols shown in Table 1, and the compounds used for comparison are indicated by the symbols shown in Table 2.

-1 Table 2

Symbol of Chemical name Remarks compound (RS)-3-allyl-2-methyl-4- bio- (A) oxocyclopent-2-enyl (1R)- allethrin trans-chrysanthemate (RS)-1-ethynyl-2-methyl-2- (B) pentenyl (1R)-cis,trans- empenthrin chrysanthemate (C) 2,2-Dichlorovinyl dichlorvos dimethylphosphate 1 Test Example 1 A mild-heating type insecticidal and/or acaricidal device (amount of active ingredient: 50 mg/bag) obtained according to Preparation Example 2 was placed in the center of the bottom of a glass chamber of 0.34 M3 (70 cm cube), and 20 adult houseflies (Musca domestica, CSMA strain) (male/female = 1/1) were released in the chamber. In this case, the temperature of heat generator of the mild-heating type ifisecticidal 10 and/or acaricidal device was 500 to 70C.

After the lapse of 30 minutes, the test insects were transferred to another vessel and given water and diet. After 24 hours, the dead and alive were counted for mortality (two replications).

Table 3 shows the results, - 1 7 - X Table 3

Compound Mortality tested (%) [II-A 100 [II-B 100 III-C 100 Untreated 0 1 Test Example 2 The following test was carried out using a mild-heating type insecticidal and/or acaricidal device (amount of active ingredient: 10 mg/mat) obtained 5 according to Preparation Example 4.

The above device was placed in the center of the bottom of a Peet Grady's chamber of 6.1 m3 (183 cm. cube), in which 50 female adult common mosquitoes (Culex pipiens pallens) had been released. Then, an electric current was passed through the device so as to adjust the heater temperature to 900 100C.

The number of knocked-down insects after the lapse of 10 minutes was counted for percentage of knocked-down insects (two replications).

Table 4 shows the results.

i 1 - 18 Table 4

Compound Knocked-down tested (%) (II-A 100 [II-B 100 III-C 100 (A) 4 (B) 20 (C) 8 Untreated 0 Test Example 3 A mild-heating type insecticidal and/or acaricidal device (amount of active ingredient: 80 mg/ mat) obtained according to Preparation Example 3 was placed in the center of the bottom of a glass chamber of 0.34 M3 (70 cm cube).

Two glass Petri dishes (diameter: 9 cm, height: 2 cm) containing 20 adults of Dermatophaqoides farinae and diet were placed in diagonal positions at 10 two corners in the bottom of the glass chamber.

In this case, the temperature of heat generator of the mild-heating type insecticidal and/or acaricidal device was 600 100C.

After 120 minutes, the dead and alive were counted for percentage of distressed or dead mites (two replicationsl.

1 1 Table 5 shows the results.

Table 5

Compound Distressed or dead tested (%) [II-A 100 [II-B 100 [II-C 100 Untreated 2.5 a 1 Test Example 4 A mild-heating type insecticidal and/or acaricidal device (amount of active ingredient:

100 mg/container) obtained according to Preparation Example 5 was placed in the center of the bottom of a glass chamber of 0.34 M3 (70 cm cube), and 20 adult German cockroaches (Blattella qermanica) (male/Eemale 1/1) were released in the chamber. In this case, the temperature of heating element of the mild-heating type insecticidal and/or acaricidal device was about 1000C.

The knocked-down insects after the lapse of 30 minutes was counted for percentage of knocked-down insects (two replications).

Table 6 shows the results.

Table 6

Compound Knocked-down tested (%) [I]-A 100 [II-B 100 III-C 100 (A) 7.5 (B) 32.5 (C) 45 Untreated 0 I Test Example 5 The device prepared according to Preparation Example 6 (amount of active ingredient: 50 mg/mat) was placed in the center bottom of a cylinder made of stainless steel having a diameter of 20 cm and a height of 80 cm. An electric current was passed through the device and the temperature of the heater of the device was adjusted to 500C. Ten female adult common mosquitoes (Culex pipiens pallens) were released in a glass tube having a diameter of 4 cm and a height of 12 cm. Then, the both end of the tube were covered with a nylon net of 16 mesh. Thus, the same two tube were - prepared. A pedestal was placed in the center top of the above stainless steel cylinder. The glass tubes were placed lengthwise on the pedestal so that the ascending current f rom, the bottom passed through the 1 tubes. 20 Minutes after placing the tubes, the tubes were taken out as they were. To the mosquitoes in the tubes was fed sugared water. 24 Hours later, the dead and alive were counted for mortality.

After the tubes had been taken out. an electric current was continued to pass through the device to keep the temperature of the heater at 500C.

The same test was repeated on lr 2 and 4 days after the start of passing through of electric current in order to examine the redidual activity.

Table 7 shows the results.

Table 7

Compound Mortality (%) tested Initial after after after 1 day 2 days 4 days [I]-A 100 100 100 100 (A) 5 5 5 0 (B) 100 100 80 40 (C) 100 25 10 0 Untreated 0 5 0 0 k

Claims (9)

WHAT IS CLAIMED IS:

1. A method for controlling insects and/or acarines comprising vaporizing 1-ethynyl-2-methyl-2 pentenyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate by mildly heating the same.

2. A method for controlling insects and/or acarines comprising vaporizing 1-ethynyl-2-methyl-2 pentenyl 3-(212-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate at a temperature which is not highe than 1000C and higher than 500C.

3. A method for controlling insects and/or acarines comprising vaporizing (lS)-l-ethynyl-2-methyl 2-pentenyl (lR)-trans-3-(2,2-dichloroethenyl)"2,2dimethylcyclopropanecarboxylate by mildly heating the same.

4. A method for controlling insects and/or acarines comprizing vaporizing (lS)-l-ethynyl-2-methyl 2-pentenyl (lR)-trans-3-(2,2-dichloroethenyl)-2,2dimethylcyclopropanecarboxylate at a temperatpre which is not higher than 100C and higher than 500C.

5. A method for controlling insects and/or acarines comprising vaporizing (lS)-l-ethynyl-2-methyl 2-pentenyl (lRS)-trans-3-(2t2-dichloroethenyl)-2,2- dimethylcyclopropanecarboxylate by mildly heating the same.

6. A method for controlling insects and/or acarines comprising vaporizing (lS)-l-ethynyl-2-methyl 2-pentenyl (IRSI-trans-3-(2,2-dichloroethenyl)-2,2- r A 1 dimethylcyclopropanecarboxylate at a temperature which is not higher than 1000C and higher than 50C.

7. A method for controlling insects and/or acarines comprising vaporizing (lRS)-l-ethynyl-2-methyl 2-pentenyl (lR)-trans-3-(2,2-dichloroethenyl)-2,2- dimethylcyclopropanecarboxylate by mildly heating the same.

8. A method for controlling insects and/or acarines comprising vaporizing (lRS)-l-ethynyl-2-methyl 2-pentenyl (lR)-trans-3-(2,2-dichloroethenyl)-2,2- dimethylcyclopropanecarboxylate at a temperature which is not higher than 1000C and higher than 500C.

9. A method according to any preceding claim substantially as herein described and exemplified.

I QMntThe Patent Office, State House, 66171 High i-iolborn. London WC1R4TP. Further copies maybe obtainedfrom The Patent Office.