JPS5840922B2 - insecticide composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides 0,0-diethyl 〇-(2,3dihydro-
The present invention relates to an insecticidal composition characterized by containing 3-oxo-2-phenyl-6-pyridazinyl) phosfluorothioate and 0,0-diisopropyl S-penzyl fluorothioate, and its purpose and The object of the present invention is to provide a drug that can effectively control leafhoppers resistant to organic phosphorus agents and carbamate agents.

After the emergence of Marathon-resistant leafhoppers in 1960, within a few years, those showing resistance to Marathon and other organophosphate insecticides became widely distributed in western Japan.

After that, NAC and MTMClM were used to control black leafhopper.
Carbamate insecticides such as IPC, CPMC, PHC, and BPMC began to be used, but from around 1969, insect pests that were resistant to these carbamates also appeared, and these insects have now spread throughout the country. Currently, there are almost no chemicals that can effectively control these leafhoppers.

Because leafhoppers transmit rice wilt and yellow wilt, it is necessary to keep their density in rice fields to a very low level, and they are often controlled using chemicals.

As a result, resistance to organophosphorus agents and carbamate agents rapidly developed.

In addition, carbamate-resistant leafhopper 4 has already appeared in areas where organophosphate-resistant insects have occurred, so it is also resistant to organophosphates.

The present inventors continued their search for a drug that can effectively control leafhoppers resistant to organophosphorus agents and carbamate agents.
Oxo-2-phenyl 6-pyridazinyl) fluorothioate (hereinafter referred to as pyridafenthione) and 0
・By using the mixture with 0 diisopropyl S-penzyl fluorothioate (hereinafter referred to as IBP), it is effective not only against insecticide-sensitive leafhoppers, but also against insecticide-sensitive leafhoppers.
It has been found that extremely excellent control effects can be obtained even against insecticide-resistant leafhoppers.

In particular, an epoch-making synergistic effect against insecticide-resistant leafhoppers, which is approximately 20 times stronger than when each agent is used alone, has been observed.

Pyridafention, which is a component of the mixture of the present invention, does not exhibit sufficient efficacy against insecticide-resistant leafhoppers, and has not been used alone to control leafhoppers.

In addition, IBP, on the other hand, shows excellent efficacy against rice blast, but does not show any insecticidal effect against pests at practical dosages.

By mixing these and applying them to insecticide-resistant leafhoppers, a synergistic effect of approximately 20 times can be obtained, and a practically excellent control effect can be obtained compared to that obtained when each agent is used alone. This is completely unexpected based on the effect shown.

A mixture of pyridafenthione and MTMC has been put to practical use as a leafhopper control agent, but no significant synergistic action has been observed in these mixtures.

The mixture of the present invention exhibits a synergistic effect about 20 times against insecticide-resistant leafhoppers, which is significantly superior to the mixed use of pyridafention and MTMC.

Furthermore, the mixture of the present invention has the advantage that it can be used for seedling box application and as a water surface application agent.

The insecticidal composition of the present invention may contain carbamate drugs such as MTMC, BPMC, NAC, MIPC, and PHC as well as other insecticides, fungicides, and herbicides as auxiliary ingredients.

The blending ratio of pyridafention and IBP in the insecticidal composition of the present invention is suitably in the range of 10:1 to 1:10, and particularly preferably in the range of 3:1 to 1:3.

In order to mix pyridafenthione and IBP and use it as an insecticidal composition, it is necessary to add a surfactant to a solid or liquid carrier commonly used in agricultural and horticultural chemicals, and if necessary, a dispersant.
By adding adjuvants such as wetting agents, it is formulated into powders, wettable powders, emulsions, granules, flowables, etc., and applied directly or diluted with water.

Next, examples of the formulation of the insecticidal composition of the present invention will be described in detail, but the types and proportions of additives are not limited to these and can be varied within a wide range.

In addition, all percentages in the formulation examples indicate weight percentages. Formulation example 1 (powder) Pyridafention 2.0%I
A powder was prepared by mixing and pulverizing BP 2.0 diatom ± 3.0 talc and kaolin mixture 93.0 or more.

Formulation example 2 (powder) Pyridafention IBP MTMC diatomaceous earth mixture of talc and kaolin 2.0% 3.0 1.5 3.0 90.5 The above was mixed and ground to prepare a powder.

Formulation example 3 (hydrating agent) Pyridafenthione IBP diatomaceous earth kaolin Sodium dotesylbenzenesulfonate Sodium ricninsulfonate 25.0% 25.0 25.0 20.0 2.0 3.0 The above was mixed and ground to prepare an irrigation agent.

Combination example 4 (emulsion) Pyridafenthione IBP xylene Polyoxyethylene alkylaryl ether 25.0% 25.0 35.0 15.0 The above ingredients were mixed and dissolved to prepare an emulsion.

Formulation example 5 (Granules) Pyridafenthione IBP Sodium dotecylbenzenesulfonate White Carbon 2.5% 2.5 2.0 10.0 Kaolin 30.0%
Talc 35.0 Bentonite 15.0 Sodium nignisulfonate 3.0 or more were mixed and pulverized, 20% water was added to the mixture, kneaded, granulated using an extrusion granulator, and dried to prepare granules. .

Next, the effects of the insecticidal composition of the present invention will be specifically explained using test examples.

Test Example 1 (Insecticidal effect on insecticide-resistant leafhopper by emulsion treatment) The emulsion was diluted with water to a predetermined concentration, and rice seedlings in the 7th stage of 3-leaf trees were immersed in this chemical solution for 5 seconds.

After the chemical solution is air-dried, the rice seedlings are covered with cages, and approximately 40 terminal instar larvae of black leafhopper resistant to organic phosphorus agents and carbamate agents are placed in the rice seedlings.
I let go of my head.

This was kept in a constant temperature room at 25° C., and after 24 hours, the mortality rate was investigated to determine the LC50 (50% lethal concentration), and synergism was determined.

Synergy is described by Y, P, 5un and R, Johnson (196
[Journal of Economics Endomoroshii (Journal OFEcon)]
omic Entomology) Volume 53 No. 5 8
pages 87-892], the synergistic action coefficient (C.

toxicity coefficient) was calculated.

The test was repeated 2 to 3 times as appropriate.

The results are shown in Table 1.

Test Example 2 (Insecticide-resistant leafhopper control effect test by powder spraying) Plant height 20-25 cm grown in a magnetic pot with a diameter of 12 crrL
crfL paddy rice (variety: Zennanfu) was covered with a wire mesh cage,
Approximately 20 final instar leafhopper larvae resistant to organophosphates and carbamates were released per pot.

After release, the inner diameter is 40crrL and the height is 55cIr1. A predetermined amount of powder was applied using a Pelger duster.

However, the reduced pressure was 20 crrLHg and the standing time was 2 minutes.

After spraying, the pockets were kept in a greenhouse, and 48 hours after spraying, the number of live and dead plants was counted to determine the dead weight percentage.

In the test, 3 pots were used per dose, and the pots were kept submerged in water to a depth of 2 cm during the test period.

Claims (1)

[Claims] 10.O-diethyl 0-(2.3-dihydro-3-oxo-2-phenyl-6-pyridazinyl)phosfluorothioate and 0.0-diisopropyl S-penzylphosfluorothioate. An insecticidal composition for controlling leafhoppers that is resistant to organic phosphorus agents and carbamate agents.