CS197727B1 - Insecticides,acaricides and ovicides - Google Patents

Abstract

Novel insecticidal, acaricidal and ovicidal compositions comprise, as active ingredient, a mixture of: (a) a compound having the general formula <IMAGE> and (b) a compound having the general formula <IMAGE> and (c) a compound having the general formula <IMAGE> wherein R and R' are different, R being C1-3alkyl and R' being C2-4alkyl. The mixture preferably contains 10.30% of component (a), 30-60% of component (b) and 10-40% of component (c); and is prepared by reacting P2S5 with mixed alkanols to give a mixture of O,O-dialkyl phosphorodithioates which may then be salified and reacted with BrCH2Cl.

Description

The present invention relates to insecticidal, acaricidal and ovicidal compositions, in particular for the protection of agricultural crops against soil-borne pests based on O, O-dialkyl-S-chloromethylditisphosphate.

The protection of agricultural crops against pests living in the field is becoming increasingly important as the intensity of crop production increases. Until recently, compositions based on chlorinated insecticide compounds such as DDT, lindane, hypochlorite, heptachlor, dieldrin, and others have been used as topical insecticides for this purpose, which are very good. in particular, they have been useful in destroying the postembrional developmental stages of insects of the order Coleoptera, Lepidoptera and - Diptera. Their great disadvantage - however, remains that they are very difficult to biodegradable, accumulate in the soil - and are transported through the plant material to the food chain. Another serious problem associated with the use of chlorinated insecticides is the fact that their repeated use has developed the resistance of many pests to them and hence the need to increase their dosage per unit area above the tolerable rate. Therefore, various formulations of organophosphoric acid esters have recently been used for the same purpose. Thus, for example, the use of paration-based compositions is known

O, O-Diethyl-O- (4-methophenyl) -tisphosphate, Diazinone O, O-Diethyl-O- (2-isopropyl-6-methylpyrimidin-4-yl) trofsulfate, Phensulfothione O, O-diethyl-O- [4-] (methylsulfinyl) -phenyl) tisfat, O-ethyl-O (2,4,5-trichlorophenyl) ethylthiophosphonate trichloronate, O, O-diethyl-S- (ethylthismethyl) dithiophosphate formate, and many other organophosphorus compounds v. combating soil-borne pests, protecting important agricultural crops such as corn, sugar beet, potatoes, cereals, cotton and much more.

The use of O, O-dialkyl-S-chloromethyldithiophosphates as insecticides and methods for their preparation are known. (German Pat. No. 1,925,468, Swiss Pat. No. 536,070, Australian Pat. No. 432,101, U.S. Pat. No. 3,896,219).

However, the above-mentioned patents do not mention the use of such a compound in either case. insecticides, and in particular as agents for controlling soil pests, such organophosphorus compounds or mixtures thereof in which two different alkyl radicals would be bonded via oxygen.

It has now been found that insecticidal, acaricidal and ovicidal O-based agents can be used to protect agricultural crops against pests, in particular against soil pests,

O-dialkyl-S-chlórmetylditiofosfátov. The insecticidal, acaricidal and ovicidal compositions according to the invention contain as active ingredient a mixture of A) of a compound of the formula I

RCk \ p_S-CH ₂ —Cl (I)

B) compounds of formula II

P - S - CH 2 - Cl (II) and C) compounds of formula III

R'O

riq

L-p-CH ₂ Cl (III) wherein R is an alkyl group of · 1-3 carbon atoms and R is alkyl having 2 to 4 carbon atoms, R is set to a mixture of 10 to 30% A, 30 · up to 60% of component B and 10 to 40% of component C.

A great advantage of the compositions according to the invention is that, depending on the ratio of the individual components of the mixture, properties such as initial and residual pesticidal activity can be varied over a wide range.

An advantage of the compositions according to the invention, for example over the conventional insecticide used hitherto. O, O-diethyl-S-chloromethyldithiophosphate (Dotan, chlormephos), has a considerably lower warm-blood toxicity while maintaining insecticidal activity. The mixtures which are the active ingredient of the compositions according to the invention can be prepared, for example, by preparing a starting mixture of O, O-dialkyldithiophosphoric acids by reaction of a mixture of aliphatic alcohols with phosphorus pentasulphide, the molar ratio of alcohols to each other being selected between approximately 8: 1 is selected for phosphorus pentasulfide (U.S. Pat. No. 2,983,644) and the acid mixture obtained after conversion to sorbent is not reacted with the appropriate chlorobromomethane in a known manner. In this way, a very advantageous composition of O, O-dialkyl-S- (chloromethyl) dithiophosphates, which is superior to its activity against the postembryonic developmental stages of insects of the genera Coleoptera, Lepidoptera and Diptera, can be obtained from the point of view of use.

The pesticidally active organophosphorus compounds of the invention may be formulated as emulsifiable concentrates, dust concentrates, dusts, wettable dusts, granular preparations and the like. Since they are also liquid in technical purity, they can be used in low volume applications. and a microcapsulated form.

The following examples illustrate but do not limit the biological effectiveness of the compositions of the invention.

For the testing of insecticidal, acaricidal and ovicidal activity, the mixtures according to the invention were used whose composition and toxicity to warm-blooded animals are given in Table 1.

Table 1 Composition of the mixture and acute oral toxicity determined in male Wistar rats.

Identification of the sample R ' Representation in% LDjo in mg kg A B C j. . C ₂ H _S C ₃ H7 24.5 48,9 · 18.6 36.0 II. CjH _s I-C4H9 27.4 57.5 14.5 145.0 III. CxH ₃ iC ₃ H7 21.0 51.0 23.0 27.5 42.0 IV. CH ₃ iC ₃ H7 12.8 43.7 20.0 in. CH ₃ C3H7 15.2 33.6 29.5 190.0 VI. CH ₃ t-CIH 19.6 42.7 32.8 340.0 VII. CH ₃ C ₂ Hs 16.7 32.1 29.1 92.0 VIII. c ₃ H, I-C3H7 21.7 51.7 25.7 84.0 IX. c ₃ H ₇ iC ₄ H ₉ 27.2 50.9 21.8 160.0 X. I-C3H7 1-C4H9 29.8 52.0 18.3 305.0 XI. C ₂ H _S 1-C4H9 18.3 42.3 39.4 160- 0 Chlormephos - standard 0,0-diethyl-S-chloromethyl-dithiophosphate C ₂ Hs C ₂ H _S 100.0 -, - 7.0

Example 1.

Workflow:

Bean plants are placed in Erlenmayer tap water flasks. A square surface of 2.5 cm is bounded on the sheet with a non-drying adhesive. 30 pieces / square of females are transferred to the square using a fine brush. The treatment is done by immersing the plant in the treated compound using geo-graded concentrations. of the order of 1.2. After soaking, the plants are placed in a tempered room (24 ° C) with a relative humidity of 60-90%. Controls are untreated females. In comparison, carbophenethion (Akarition) is used as standard. The results of the acaricidal activity tests are shown in Tables 2 and 3.

Example 2..

Determination of acaricidal ovicidal effect on Tetra.nychus urticae eggs.

Work procedure:

Place filter paper rings (09 cm) on a round PVC pad and saturated with water. A sheet of beans is placed on the paper and a square of 2.5 cm side is marked. The dd of the creators are spotted from 12-15 females and stored in a tempered room (24 ° C ± 1 ° C, 60-90% relative humidity). After 24 hours, the females are removed from the squares.

The treated substances are applied to the eggs by spraying with the aid of an atomizer using graded doses according to geometry. 1,2 series and a total volume of 2 ml / 2 sheets. The number of eggs / leaf is counted using a stereoscopic microscope. The treated material is placed in a tempered room where it is incubated for 7 to 9 days. The rings supplying the bean leaf are kept constantly moist. Untreated eggs serve as control. For comparison, standard carbofention (Akarition) is used. The results are shown in Table 2.

Example 3.

Determination of the contact affinity effect by Aphis fabae by the immersion method. Workflow:

33 aphids of a homogeneous population are loaded onto a 4 cm 4 gauze cylinder at the bottom and covered with a Petri dish. The treated substance is applied by dipping the aphids (3 x 3 sec.) Using graded stages of geometric order 1.2. After application, the waxes are dried on filter paper. After drying, the apricot cylinders are placed in petri dishes in which a filter paper ring is inserted. Controls are untreated waxes. Standard malation is used for comparison. The results are shown in Table 2.

Table 2.

Sample designation Conc. acc. in ppm. T. urticae female % efficiency of A. fábae T. urticae eggs I. 100 ioo 100 500 _ 100 1 000 100 100 5 000 - 100

II. 100 100 - 500 -. - 72 I 000 100 - 5 000 - - 100 IH. 100 100 _ 500 - - 82 1 000 100 - - 5 000 - - 100 Akarition-Standard 100 100 _ O, O-diethyl-S-4 / chloro- 500 - 100 phenylthiomethyl dithio- 1 000 100 - - phosphate 5 000 - - 100 malathion-Standard 100 100 __ O, S-O'dimetyl / l, 2-dicarbethoxy / ethyldi-thiophosphate 1 000 100

Table 3. Comparison of the acaricidal efficacy of the individual components and their experimental mixtures.

Sample designation LCso Chlormephos toxicity index chlor mefoS'Standard O, O-diethyl S-chlórmetylditiofosfát 0.0031 100.0 0,0-diisobutyl-S-chlórmetylditiofosfát ’0.15 2.0 O-ethyl-O-iso-Schlórmetyiditiofosfát 0,013 23.8 II. 0.0019 163.0

Example . 4th

The efficacy of the compounds of the invention on wireworms (Elateridae larvae) was investigated. as follows:

The soil into which the experiment is set is first dried, sieved and adjusted to the desired structure. The soil thus prepared is weighed in increments of 200 g per concentration. The weighed soil is poured into a two-liter duster together with a precisely weighed preparation. The powder is sealed and mixed for 5 minutes on a mechanical mixer. The so prepared soil is poured into rollers (height 12 cm, diameter 5 cm), the inside of which is reinforced with plastic foil, the bottom part of the plastic foil is attached to the roller using a nylon fabric and fastened with a rubber band. The treated roller is placed on a Petri dish - nylon fabric downwards. Five wire rods are placed in each roller and the surface is covered with 10 ml of water. In order to prevent cannibalism between individual wireworms, 3 corn seeds are added to each roller. The rollers are then placed in the. rooms with a temperature of 22 ± 2 ° C and relative humidity. Each concentration is done in 6 replicates. Every two days, each roller is poured with 10 ml of water. After 14 days, the experiment was evaluated by counting dead wireworms. The average percentage of deaths was calculated from three replicates. wireworms.

The residual effect after 14 days was determined equally, except that the wireworms were loaded 14 days after the start of the experiment (mixing the soil with the preparation and pouring into the rollers.) It was also evaluated after 14 days. The results are shown in Tables 4, 5, 6, 7, 8 and 9.

Example 5

The following method was used to assess the biological efficacy of the organophosphorus compound mixtures of the invention against soil pests.

The compounds of the invention were formulated as a dusting powder, standard Dotan as a 5% granulate, standard pyridation as a 10% granulate.

From the dried and sieved soil, spreads were prepared on the basis of the mixtures according to the invention or organophosphorus compound-based compositions used in the fight against soil pests so as to achieve the desired final concentrations of active substances in the soil. Of the prepared soil samples containing the active substances, 50 g each were weighed, as shown in Table 4.

Sample designation Active substance concentration in ppm Initial effect Residual effect I. 12 100 100 6 93 100 3 93 100 1.5 73 86 II. 12 100 100 6 100 100 3 80 90 1.5 14 60 pyridation-Standard 12 100 100 O-ethyl-O-isopropyl-O- 6 73 100 - / 5-methoxy-l-methyl-6- 3 73 100 -oxo-1H-pyridazin-4-yl) 1.5 33 53 thiophosphate

Table 5. Insecticidal effect of a dose of 0.0012% active ingredient determined under laboratory conditions. Exposure time 7 days.

Sample designation mortality in% XI. 100 O-ethyl-O-isopropyl-O- (5-methoxy-1-methyl-6-oxo-1H-pyridazin-4-yl) thiophosphate pyridation standard 100 inspection 0

ТаЬиГка 6. Residual efficacy against wireworms after treatment at the Malinovo site (May 1978).

Sample designation Active substance in kg. ha ^-1 Biological efficiency in% 14 days 28 days XI. 1 63.3 96.6 56.6 86.6 1.5 2 100 100 2.5 100 100 3 100 100

Dursban 5G = chlorpyrifos- -Standard 0,0-diethyl-0-3,5,6-trichloro-2-pyridyltiofosfát 2 86.6 93.3

Dyfonate 10G = phonophos-standard O-ethyl-S-phenylethyldithiophosphonate

93.3 100

Furadan 5G = carbofuran-Standard 2,3-dihydro-2,2-dimethylbenzofuran-7-ylmethylcarbamate

100 96.6

Dotan 5G = chlorormephos- ‘ -Standard O, O-diethyl S-chlórmetyI- dithiophosphate 2 100 100 You issue 10G = oxamyl-standard 1-dimethylcarbamoyl-l-metyltiometylénamínometylkarbamát 3 100 100 Disystone 5G = disulfoton-standard Ο, Ο-diethyl-S-etyltioetylditiofosfát 2 96.6 100 Inspection (untreated) 0 0

Table 7. Residual efficacy against wireworms after treatment at the Malinovo site (April 1978).

Sample designation

Active substance in kg. ha ' ¹

Biological efficacy in% days 28 days 42 days

XI.

1 82.5 93.3 96.6 1.5 83.3 96.6 83.3 2 100 100 100 2.5 93.3 100 100 3 100 100 100

Dursban 5G = chlorpyrifos-standard

O, O-diethyl O-3,5,6-trichloro-2-pyridyltiofosfát

76.3 86.3 50

Dyfonate 10G = phonophos-Standard O-ethyl-S-phenylethyldithiophosphonate

100 96.6 98.7

100 100 100

Furadan 5G = carbofuran-standard

2,3-dihydro-2,2-dimethylbenzofuran-7-ylmethylcarbamate

Tab. 7

Dotan 5G = chlorormephos-standard Ο, Ο-diethyl-S-chloromethyldithiophosphate 2 96.6 100 100 You issue 10G = oxamyl-standard 1-T-dimetylkaгbamoyl metyTtiometylénaminometylkarbamát 3 100 100 86 Disystone 5G = disulfotone-standard 0,0-diethyl-S-ethylthioethyldithiophosphate 2 100 96.6 86.6 Inspection (untreated) - 0 0 0

TABLE 8. Residual efficacy against wireworms after fall treatment in Vlčany (May 1978).

Sample designation Active substance . in kg. ha ^_1 Biological efficiency in% 14 days 28 days XI. 1 30 66.6 1.5 56.6 66.6 2 66.6 93.3 2.5 96.6 100 3 100 100 Dursban 5G = chlorpyrifos-standard 2 56.6 96.6 O, O-diethyl-0-3,5,6-trichloro-2-pyridyltiofosfát

Dyfonate 10G = Phonophos-standard 3 100 100

O-ethyl-S-fenyletylditiofosfonát

Furadan 5G - carbofuran-standard 2,3-dihydro-2,2-dimethylbenzofuran-7-ylmethylcarbamate

93 100

Dotan 5G = chlorormephos -standard O, O-diethyl-S-chloromethyldithiophosphate 2 100 100 You issue 10G = oxamyl-standard 1-Dimethylcarbamoyl-1-methylthiomethyleneaminomethylcarbamate 3 93.3 100 Disyston 5G - disulfoton-. -O-O-diethyl-S-ethylthioethyldithiophosphate standard 2 93.3 96.6 Inspection (untreated) - 0 0

Table 9. Initial effect on wireworm expressed as mortality in%. Exposure time 3 days.

Sample designation Active substance concentration in% 0.0012 0.0006 0.0003 0.0001 chlormephos-Standard O, O-diethyl S-chloro- 93 73 57 33 metylditiofosfát XI. 87 50 23 13 inspection 0 0 0 0

T

Table 10. Sample designation Active ingredient dose in ppm Average% mortality I. 24 70 12 36 6 20 II. 24 73 12. 56 6 40 III. 24 93 12 90 6 60 IV. 24 93 12 80 6 26 IN. 24 76 12 53 6 10 VI. 24 100 12 86 6 73 chlorormephos-Standard O, O-diethyl- 24. 76 S-chlormetylditiofosfát 12 46 6 36 pyridation-Standard O-ethyl-O-iso- 24 76 propyl-0- / 5-methoxy-l-methyl-6-oxo- 12 46 -1H-pyridazin-4-yl-thiophosphate 6 30

into the petri dishes and after 7 or 21 or 35 days, 4 ml of water and 20 pieces of 4-day-old larvae of Musea domestica L. were added to each dish. C, left for 14 days, and finally the hatched flies were counted. The efficacy of the compounds or mixtures used was expressed as the average percentage of larval mortality. The results obtained are summarized in Tables 10 and 10 ^. 11th

Example 6.

The effect of the compounds of the invention was followed by a model test on Tenebrio molitor L. larvae, by a method identical to Example 4 except that no corn was added to the soil. The results are shown in Tables and 13.

ТаЬиГка И. Sample efficacy on soil fly flies larvae determined under laboratory conditions and expressed as mortality in%.

Sample designation Account concentration substances in% Effectiveness after 7 days and 21 days 35 days First 0.0010 90 96 0.0006 66 73 - II. 0.0010 100 100 100 0.0006 53 100 90 III. 0.0010 96 100 0.0006 66 96 - IV. 0.0010 86 100 - 0.0006 50 100 - IN. 0.0010 100 100 _ 0.0006 100 100 - VI. 0.0010 100 100 96 0.0006 80 100 80 VII. 0.0010 96 100 _ 0.0006 90 70 - VIII. 0.0010 83 93 _ 0.0006 60 43 - IX. 0.0010 70 90 - 0.0006 86 80 - X. 0.0010 46 0 - 0.0006 23 0 - Chlormephos-Standard 0.0010 66 100 - O, O-diethyl-S-chloromethyldithiophosphate 0.0006 56 43

ТаЬиГка 12.

Sample designation Dose of active ingredient in ppm Initial Effect% Mortality II. 12 95 6 64 3 38.5 1.5 0 pyridation-Standard 12 100 0-ethyl-0-isopropyl-0- / 5-meth- 6 90 hydroxy-l-methyl-6-oxo-pyridazin 3 50 -4-yl / thiophate 1.5 12.5

Table 13. Potency of samples on Tenebrio molitor L. larvae in soil determined under laboratory conditions and expressed as mortality in%.

Sample designation Account concentration substances in% Effectiveness after 7 days 14 days 21 days I. 0.0005 100 100 0.0003. 100 73 - II. 0.0005 100 100 100 0.0003 100 100, 100 III. 0.0005 0.0003 100 100 86 100 - IV. 0.0005 100 100 0.0003 100 100 - in. 0.0005 100 100 0.0003 93 83 - VI. 0.0005 100 100 100 0.0003 100 100 100 VII. 0.0005 100 100 0.0003 . 100 100 - VIII. 0.0005 0 0 - 0.0003 0 0 - IX. 0.0005 0 0 _ 0.0003 0 0 - X. 0.0005 26 13 _ 0.0003 0 0 - Chlormephos-Standard 0.0005 0.0003 100 100 100 O, O-diethyl S-chlórmetylditiofosfát 100 93 100

I

Claims (1)

SUBJECT INVENTION Insecticidal, acaricidal and ovicidal agents for the protection of agricultural crops against pests based on O, O-dialkyl-S-chloromethylditisphosphates, characterized in that they contain, as an active ingredient, a mixture of: A) compounds of formula I RO \ \ p_s_ ^ ch ₂ —i (I) ^R B) compounds of formula II RO ₄ > P_S-CH ₂ -Cl (II) ^R 10 and C) compounds of formula III Ri (\ p-S-CH-Cl (III)) In which R is a C 1 -C 3 alkyl group and R 1 is a C 2 -C 4 alkyl group different from R, the mixture comprising 10 to 30% of component A, 30 to 60% of component B and 10 to 40% Component C.