Insecticidal and Acaricidal Composition and Method With Triazolyl Phosphoric Esters Acid

The following examples will serve to illustrate the preparation of compounds according to the invention and their properties:

a. 23.9 g 1-(3-trifluoromethylphenyl)-semicarbazide and 14.8.g orthoformic acid ester were heated together with 40 ml glycol monomethyl ether whereon a clear yellow solution was obtained. The ethanol forming at an internal temperature of 120.degree.C was continuously distilled off. After 41/2 hours the mixture was allowed to cool and treated with 200 ml ether. The compound of the formula ##SPC1##

was obtained, having a decomposition point of 210.degree.C.

b. 40 g 1-(3-trifluoromethylphenyl)-3-hydroxy-1,2,4-triazole and 23.6 g potash were heated for 1 hour under reflux together with a spatula point of copperbronze in 400 ml methyl ethyl ketone. Then 32.2 g O,O-diethyl thiophosphoric acid chloride were added dropwise at 50.degree.C. After three hours heating under reflux, the solvent was evaporated in vacuo. The residue was taken up in ether and washed successively with water, 0.5N HCl, saturated bicarbonate solution and brine. After drying over sodium sulphate the ether was evaporated in vacuo to leave the crude product. By filtration through 800 g silica gel with methylene chloride as solvent, the compound of the formula ##SPC2##

is obtained. M.Pt.: 37.degree.-39.degree.C.

The following compounds were also made in analogous fashion:

Cotton and potato plants are sprayed with a 0.05% aqueous emulsion (obtained from a 10% emulsifiable concentrate).

After the coating has dried, Disdercus fasciatus nymphs are settled on the cotton plants and Colorado potato beetle larvae (Leptinotarsa decemlineata) on the potato plants. The test is carried out at 24.degree.C and 60% relative humidity. In the above test the compounds according to Example 1 displayed good ingest poison action against Disdercus fasciatus and Leptinotarsa decemlineata.

a. Action on mites (Tetranychus urticae)

For testing the acaricidal action bean leaves infested with adults, rest stages and eggs of the red spidermite (Tetranychus urticae), were treated with a 0.05% aqueous emulsion of the substance to be tested (made from a 25% emulsifiable concentrate). The test was evaluated after 6 days. Phosphoric acid ester resistant strains of red spidermite were used as test animals.

b. Action on ticks (Boophilus microplus) and their development stages

For the following test in each case 10 adult ovipositing ticks were dipped for three minutes in aqueous emulsions of active substance (Concentrations: 800; 400; 200; 100; 50; 10 and 1 ppm).

The ticks were then kept at 27.degree.C and 80% relative humidity. Egglaying was determined at the 5th, 10th and 15th day.

The compounds according to example 1 tested according to the above tests (a) and (b) showed good action against Tetranychus urticae and Boophilus microplus.

To test the action against soil nematodes, the active substance (in the concentration indicated in each case is applied to and intimately mixed with soil infected with root gall nematodes (Meloidgyne avenaria). Immediately afterwards, tomato cuttings are planted in the thus prepared soil in a series of tests and after a waiting time of 8 days tomato seeds are sown in another test series.

In order to assess the nematocidal action, the galls present on the roots are counted 28 days after planting and sowing respectively. The compounds according to Example I display good action against Meloidgyne avenaria is this test.