DD262790A1 - AKARICIDAL AGENTS - Google Patents

Abstract

The invention relates to novel acaricidal agents for combating pflanzenschaedigenden mites in arable crops, taking into account the prevention of resistance formation, which are characterized in that they contain as an effective component at least one substituted quinoxaline of the general formula (I), in which R1 is hydrogen or methyl and R2 if necessary subst. Aryl or hetaryl mean. Formula (I)

Description

Characteristic of the known state of the art

Plant-damaging mites are widespread worldwide and of great economic importance as a direct pest in vegetable growing under glass and plastics as well as in the field, in fruit and hops, in ornamental plants, in cotton, tea and other important crops. For the control of these mites, a number of effective chemical compounds are known, which have more or less economic and / or technical defects. Sosteilen u.a. with repeated use of the same active ingredients resistance phenomena, which makes their substitution by acaricides with different chemical structure (rotation of the means) required. Hence the need to constantly develop new effective acaricides with the trend towards specialty acacia for certain crops.

Substituted quinoxalines have been described in many cases as biologically active. Thus, according to a review of the literature (Pharmazie 36 [1981] 368), quinoxaline derivatives are antibacterial, viricidal, antihelminthic, antiprotozoic, antimycetic, ergotropic, analgesic, antiphlogistic, spasmolytic, antihypertensive and / or hypnotic. Further, quinoxalines having fungicidal (J. Agr. Food Chem. 19 [1971] 298), insecticidal (JP P 149015-80, JP P 46851-81) and herbicidal (e.g., CA. 97 [1982] 19-163024 c, 96 [1982] 21-181307f). Representatives with herbicidal activity have become known in the series of aryl- or hetaryl-substituted quinoxalines (eg phenylquinoxalines (CA 87 [1977] P 195546 j; 91 [1979] 193335 y) and furyl- or thienylquinoxaline (CA88). 1978] P 165490q); some phenyl- and furyl-quinoxalines (Pharmazie 36 [1981] 368; Chim.farm.Z.2 (1968) 14; Gidroliz Proizvod. 1978, 17) as well as furyl, thienyl or pyridyl -quinoxaline-1,4-dioxides (Swiss Appl.2729 / 70) show antibacterial or antimicrobial effects, various hetarylquinoxalines act algicide (WP: A01 N / 300461-6)

 The acaricidal activity of quinoxalines has not yet been reported.

Object of the invention.

The aim of the invention is the development of new effective means for controlling plant-damaging mites, which are equal to or superior to the previously applied acaricides in their effect on plant pests, do not damage crops and natural enemies of the mites and keep in this way the pest infestation below the economic damage threshold.

Explanation of the essence of the invention

The invention has for its object to develop new acaricidal agents based on new chemical agents to accelerate the currently particularly urgent need for rotation of acaricidal agents to prevent resistance phenomena, and thus to avoid yield loss in crop cultivation by a beneficial control of pests.

According to the invention, this object is achieved in that substituted quinoxalines of the general formula I.

(D

in the R ^{1 is} hydrogen or methyl and R ² optionally subst. Aryl or hetaryl, as acaricidal agents find use. The compounds of the invention can be prepared analogously to known synthetic methods: / Gazz.chim.ital.89 [1959] 1598; Bull.Soc.chim. France 1961,933; Z. Chem. 22 (1982) 300; Pharmacy 38 (1983) 829; 40 (1985) 384; Ber.dtsch.Chem.594 (1955) 185. They are listed by way of example in Table 1.

The compounds of the formula I can be used as such or in combination with a suitable additive as acaricidal agents. Suitable additives are, for example, solvents, diluents, emulsifiers, thickeners and adhesives, as well as other crop protection and pesticides.

The agents which contain the active compounds of the formula I can be applied in a wide variety of forms, for example as emulsions, suspensions, dusting powders, dispersions, fog agents or microgranules. The type of application depends exclusively on the intended use. The preparation of the active ingredient formulations suitable for the various application forms can be carried out according to the mixing and milling methods customary in formulation technology.

In practice, the compounds of formula I can be applied in concentrations of 100 to 1000 ppm, especially in the concentration range of 200 to 500 ppm, depending on the nature of the treatment to be carried out, the time and stage of development of the pest population.

The following examples are intended to illustrate the invention without limiting it.

Example 1:

Ovicidal activity against Tetranychus urticae Koch.

Leaf discs of Phaseolus vulgaris were coated with summer eggs of Tetranychus urticae and sprayed with an aqueous suspension or emulsion of various concentrations of the drug to be tested. After complete larval hatching in the untreated control, the number of hatched larvae in the treated test members was determined.

The results calculated as percentage mortality rates are shown in Tables 2 and 3.

Example 2:

Adulticide action against females of Tetranychus urticae Koch.

One leaf of Phaseolus vulgaris was occupied by 25 females of Tetranychus urticae.

2 leaves per test member were sprayed with aqueous suspensions of various concentrations of the test compound. After 48 hours, the number of females killed was determined. The calculated as percent mortality rate results are shown in Table 2.

Example 3:

Preparation of a wettable powder for the preparation of suspensions

 The following components are mixed and then finely ground:

- active ingredient 20Ma .-% according to the invention

- inert material 45Ma .-%

- grinding aid 25Ma .-%

- Mixture of nonionic u

 anion-active surfactants 10Ma .-%

Example 4:

Determination of plant tolerance

Tomatoes (1), celery (2) and field bean (3) were used as test plants. They were sprayed dripping wet with aqueous suspensions of the formulated active ingredients. After 3 to 14 days, the visual assessment of the degree of damage of the plants was carried out according to the following rating scheme.

Boniturnote Damage to plants in% 0 0 1 to 25 2 26 to 25 3 > 75

The results are summarized in Table 4.

table

Ser. ITr.

3 4 5 6

8 9

10

11 12

13 14 15 16 17

GH ₃ GH ₃ GH ₃

Jfp ⁽⁰ G)

96.8 0 99.4 9.3 99.1 2.2 100.0 10.6 100.0 28.3 76.8 10.6 77.9 4.1

table

Acaricidal activity against Tetranychus urticae cook

Drug mortality rate (%)

Ser. No. Tab.

1000 ppm AS ovicidal adulticide

table

Acaricidal activity against eggs of Tetranychus urticae Koch after administration of various AS concentrations

Drug mortality rate ovicide (%) at the concentration (ppm)

Ser. Nr.Tab. 1 1000 800 400 200

table

Determination of phytotoxicity at 2000ppm AS

96.8 99.4 98.4 93.3 80.0 99.4 94.2 95.8 98.7 78.5 99.1 93.6 62.1 63.9 20.7 100.0 99.4 99.4 80.4 44.4

active substance test plant 2 3 Lfd.Nr.Tab.1 1 Boniturnote 0 2 2 0 0 1 3 0 0 1 4 0 0 1 5 0

Claims (1)

Acaricidal agent, characterized in that it contains as active ingredient at least one substituted quinoxaline of the general formula I in which R ^{1 is} hydrogen or methyl and R ^{2 is} unsubstituted or substituted. Aryl or hetaryl mean, in addition to the usual carriers, solvents and / or formulation auxiliaries. (I) Field of application of the invention The invention relates to novel acaricidal agents for controlling plant-damaging mites in cultivated plant stands, which are characterized in that they contain as an effective component at least one quinoxaline derivative.