GB1570826A - Phosphorus dithioate insecticidal composition - Google Patents

Description

(54) PHOSPHORUS DITHIOATE INSECTICIDAL COMPOSITION (71) We, BASF AKTIENGESELL SCHAFT, a German Joint Stock Company of 6700 Ludwigshafen, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to insecticidal compositions of phosphorus dithioates and the use thereof.

The preparation and use of 0,0 dimethyl - S - (phenylcarbethoxymethyl) phosphorus dithioate (German Printed Application DAS 1,011,416) and 0,0 dimethyl - S- (N - methylcarbamoylmethyl)- phosphorus dithioate (German Patent No. 819,998) as insecticidal active ingredients is known. The action of the two compounds differs considerably from pest to pest. 0,0 - dimethyl - S (phenylcarbethoxymethyl) - phosphorus dithioate has a particularly good action on caterpillars and various beetle species, e.g., granary weevil (Sitophilus granarius), whereas its action is unsatisfactory on aphids (e.g., Aphis fabae and Megoura viciae), ticks (e.g. Ornithodorus moubata) and cockroaches (e.g. Blatta orientalis). By contrast, 0,0 - dimethyl - S - (N - methylcarbamoylmethyl)- phosphorus dithioate has a very good action in combatting aphids, ticks, cockroaches and crickets.

We have now found that insecticides containing as active ingredients a mixture of 0,0 - dimethyl - S- (phenylcarbethoxymethyl)- phosphorus dithioate of the formula

and 0,0 - dimethyl - S- (N- methylcarbamoylmethyl)- phosphorus dithioate of the formula

have a far better insecticidal action than the individual active ingredients. This action is superior to the sum of the actions of the two individual compounds, and takes effect in particular where there is a gap in the action of one of the two mixture components. This synergistic action is surprising and was not foreseeable.

The use of the compositions of the invention offers considerable advantages, as the amounts of active ingredient required to achieve the same effect are smaller than when the individual components are used.

The insects can therefore be combatted less dangerously and more economically; the minimum interval to be observed between treatment and harvesting can be considerably reduced.

Both active ingredients have the advantage of a low toxicity to warm bloods: from 250 to 400 mg/kg rat per os for 0,0 dimethyl - S - (phenylcarbethoxymethyl) phosphorus dithioate, and from 215 to 265 mglkg rat per os for 0,0 - dimethyl - S (N - methylcarbamoylmethyl) phosphorus dithioate.

In the compositions of the invention, the weight ratio of the active ingredients is in general from 1:5 to 5:1. Particularly good results may be obtained with weight ratios of from 1:3 to 3:1.

Application may be effected for instance in the form of directly sprayable solutions, powders, suspensions, dispersions, emulsions, oil dispersions, pastes, dusts, broadcasting agents, ultra-low-volume sprays or granules by spraying, atomizing, dusting, broadcasting or watering. The forms of application depend entirely on the purpose for which the agents are being used; in any case they should ensure a fine distribution of the active ingredient.

For the preparation of solutions, emulsions, pastes and oil dispersions to be sprayed direct, mineral oil fractions of medium to high boiling point, such as kerosene or diesel oil, further coal-tar oils, etc. and oils of vegetable or animal origin, aliphatic, cyclic and aromatic hydrocarbons such as benzene, toluene, xylene, paraffin, tetrahydronaphthalene, alkylated naphthalenes and their derivatives such as methanol, ethanol, propanol, butanol, chloroform, carbon tetrachloride, cyclohexanol, cyclohexanone, chlorobenzene, isophorone, etc., and strongly polar solvents such as dimethylformamide, dimethyl sulfoxide, N- methylpyrrolidone, water, etc. are suitable.

Aqueous formulations may be prepared from emulsion concentrates, pastes, oil dispersions or wettable powders by adding water. To prepare emulsions, pastes and oil dispersions the ingredients as such or dissolved in an oil or solvent may be homogenized in water by means of wetting or dispersing agents, adherents or emulsifiers. Concentrates which are suitable for dilution with water may be prepared from active ingredient, wetting agent, adherent, emulsifying or dispersing agent and possibly solvent or oil.

Examples of surfactants, are: alkali metal, alkaline earth metal and ammonium salts of ligninsulfonic acid, naphthalenesulfonic acids, phenolsulfonic acids, alkylaryl sulfonates, alkyl sulfates, and alkyl sulfonates, alkali metal and alkaline earth metal salts of dibutylnaphthalenesulfonic acid, lauryl ether sulfate, fatty alcohol sulfates, alkali metal and alkaline earth metal salts of fatty acids, salts of sulfated hexadecanols, heptadecanols, and octadecanols, salts of sulfated fatty alcohol glycol ether, condensation products of sulfonated naphthalene and naphthalene derivatives with formaldehyde, condensation products of naphthalene or naphthalenesulfonic acids with phenol and formaldehyde, polyoxyethylene octylphenol ethers, ethoxyfated isooctylphenol, ethoxylated octylphenol and ethoxylated nonylphenol, alkylphenol polyglycol ethers, tributylphenol polyglycol ethers, alkylaryl polyester alcohols, isotridecyl alcohols, fatty alcohol ethylene oxide condensates, ethoxylated caster oil, polyoxyethylene alkyl ethers, ethoxylated polyoxypropylene, lauryl alcohol polyglycol ether acetal, sorbitol esters, lignin sulfite waste liquors and methyl cellulose.

Powders, dusts and broadcasting agents may be prepared by mixing or grinding the active ingredients with a solid carrier.

For application in spray form, the active ingredient composition may be introduced together with a solubilizer and a conventional propellant into pressurized cans.

Granules, e.g., coated, impregnated or homogeneous granules, may be prepared by bonding the active ingredients to solid carriers. Examples of solid carriers are mineral earths such as silicic acid, silica gels, silicates, talc, kaolin, Attaclay, limestone, lime, chalk, bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate, magnesium oxide, ground plastics, fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate, and ureas, and vegetable products such as grain flours, bark meal, wood meal, and nutshell meal, cellulosic powders, etc.

The amount of active ingredient in the formulations may vary within wide limits. It depends inter alia on the ratio of the components to each other, the type of formulation, the method of application employed, the degree of success desired, and the insects to be combatted. Depending on the form of formulation selected, the amount of active ingredient composition may be from 0.1 to 99, preferably from 0.5 to 95, wt%.

There may be added to the compositions (if desired, immediately before use (tankmix)) oils of various types, herbicides, fungicides, insecticides and bactericides.

These agents may be added to the compositions of the invention in a ratio by weight of from 1:10 to 10:1.

The following are examples of advantageous formulations: 1.

250 g 0,0 - dimethyl - S (phenylcarbethoxymethyl) - phosphorus dithioate 250 g 0,0 - dimethyl - S- (N methylcarbamoylmethyl) - phosphorus dithioate 20 g calcium dodecylbenzene sulfonate 30 g wetting agent (adduct of approx. 40 moles of ethylene oxide to 1 mole of caster oil) 200 g cyclohexanone xylene make up to 1,000 ml 2.

125 g 0,0 - dimethyl - S (phenylcarbethoxymethyl) - phosphorus dithioate 375 g 0,0 - dimethyl - S- (N- methylcarbamoylmethyl) - phosphorus dithioate 24 g calcium dodecylbenzene sulfonate 16 g wetting agent (alkoxylation product of 25 moles of propylene oxide and 40 moles of ethylene oxide, added to isooctylphenol) 200 g cyclohexanone xylene make up to 1,000 ml 3.

375 g 0,0 - dimethyl - S (phenylcarbethoxymethyl) - phosphorus dithioate 125 g 0,0 - dimethyl - S- (N- methylcarbamoylmethyl) - phosphorus dithioate 10 g calcium dodecylbenzene sulfonate 10 g wetting agent (alkoxylation product of 25 moles of propylene oxide and 40 moles of ethylene oxide, added to isooctylphenol) 200 g cyclohexanone xylene make up to 1,000 ml.

Numerous iniurious and troublesome insects can be successfully combatted with the compositions according to the invention, for instance representatives of the Orthoptera order, such as Blatta, Blattella, Perip Ian eta, Gryllotalpa, Locusta, Schistocerca, and Acheta; representatives of the Isopteva order, such as Reticulitermes, Kalotermes and Hodotermes; representatives of the Dermaptera order, such as Forficula; representatives of the Thysantop.tora order, such as thrips; representatives of the Heteroptera order, such as Cimex, Piesma, D ysdercus, Rhodnius, Oxycarenus, Nezara, and Lygus; representatives of the Homoptera order, such as Cicadetta, Perkinsiella, Nilaparvata, Tomaspis, Typhlocyba, Macrosteles, A leurodes, Psylla, Aphis, Chermes, and Pseudococcus; representatives of the Coleoptera order, such as Leptinotarsa, Bruchus, Ptinus, Dermestes, Sitophilus, Elater, Cleonus, Hylobius, Stephanoderes, Orthiorhynchus, Apion, Chrysomela, Epilachna; representatives of the Lepidoptera order, such as Pieris, Malacosoma, Lymantria, Mamestra, Heliothis, Spodoptera, Carpocapsa, Lobesia, Tortrix, Chilo, Pyrausta, and Hyponomeuta; and representatives of the Diptera order, such as Musca, Fannia, Culex, Aedes, Tipula, Ceratitis, Calliphora, Sarcophaga, Glossina, and Simulium.

The following experiments demonstrate the superiority of the compositions of the invention over their individual active ingredients. In the tables the active ingredient 0,0 - dimethyl - S - (phenylcarbethoxyphenyl)- phosphorus dithioate is designated A, and the active ingredient 0,0 - dimethyl - S - (N - methylcarbamoylmethyl) - phosphorus dithioate is designated B.

EXAMPLE 1 Action on Oriental Cockroach (Blatta Orientalis) Adult cockroaches are introduced into 1 liter beakers whose walls have previously been treated with acetonic solutions of the individual active ingredients A or B, or with active ingredient compositions with different A:B weight ratios. The mortality rate is determined after 48 hours. The LCso is determined graphically by the method disclosed by Litchfield and Wilcoxon in J.

Pharm. a. Exper. Therap., 96, 99-113, 1949. The dose-effect values are plotted on logarithmic-probability paper, the best straight line is fitted through the points, and the LC50 read off.

Weight Active ratio ingredient A:B LC50 [mgl A 0.140 B 0.023 A+B 3:1 0.046 A+B 1:3 0.025 EXAMPLE 2 Action on Granary Weevil (Sitophilus Granarius) Granary weevils are introduced into Petri dishes 10 cm in diameter which have previously been treated with acetonic solutions of the individual active ingredients A or B or of compositions thereof in different weight ratios. After 60 minutes the weevils are transferred to untreated- observation vessels. The mortality rate is determined after 24 hours. The LC50 is determined herefrom as described in Example 1.

Active Weight Ingredient ratio A:B LC50 [mg] A 0.0096 B 0.1420 A+B 3:1 0.0077 A+B 1:3 0.0660 EXAMPLE 3 Action on Caterpillars of the Cabbage Moth (Barathara Brassicae) Young cabbage leaves are dipped for 3 seconds in aqueous emulsions of the individual active ingredients A or B or of compositions thereof in different ratios.

After the leaves have dried, they are put in Petri dishes and caterpillars of the cabbage moth in the 4th larval stage are placed on them. The mortality rat is determined after 24 hours; the LCso is determined therefrom as described in Example 1.

Active Weight ingredient ratio A:B LC50[mg] A 0.0057 B 0.0620 A+B 3:1 0.0062 A+B 1:3 0.0160 WHAT WE CLAIM IS: 1. An insecticide comprising a mixture of 0,0 - dimethyl - S- (phenylcarbethoxymethyl)- phosphorus dithioate of the formula

and 0,0 - dimethyl - S - (N methylcarbamoylmethyl) - phosphorus dithioate of the formula

as active ingredients.

2. An insecticide as claimed in claim 1, wherein the weight ratio of the specified active ingredients is from 5:1 to 1:5.

3. An insecticide as claimed in claim 1 or 2, wherein the total concentration of the specified active ingredients is from 0.5 to 95 wt %.

4. An insecticide as claimed in claim 1 and substantially as hereinbefore described or exemplified.

5. A process for producing an insecticide as claimed in claim 1, wherein the specified active ingredients are mixed with a solid or liquid carrier.

6. An insecticide when produced by a process as claimed in claim 5.

7. A process for combatting insects, wherein an insecticide as claimed in any of claims 1 to 4 or 6 is allowed to act on the insects or their habitat.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. Active Weight ingredient ratio A:B LC50[mg] A 0.0057 B 0.0620 A+B 3:1 0.0062 A+B 1:3 0.0160 WHAT WE CLAIM IS:

1. An insecticide comprising a mixture of 0,0 - dimethyl - S- (phenylcarbethoxymethyl)- phosphorus dithioate of the formula

and 0,0 - dimethyl - S - (N methylcarbamoylmethyl) - phosphorus dithioate of the formula

as active ingredients.

2. An insecticide as claimed in claim 1, wherein the weight ratio of the specified active ingredients is from 5:1 to 1:5.

3. An insecticide as claimed in claim 1 or 2, wherein the total concentration of the specified active ingredients is from 0.5 to 95 wt %.

4. An insecticide as claimed in claim 1 and substantially as hereinbefore described or exemplified.

5. A process for producing an insecticide as claimed in claim 1, wherein the specified active ingredients are mixed with a solid or liquid carrier.

6. An insecticide when produced by a process as claimed in claim 5.

7. A process for combatting insects, wherein an insecticide as claimed in any of claims 1 to 4 or 6 is allowed to act on the insects or their habitat.