RU2433589C1 - Method to control larvae of bloodsucking insects - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to method to control larvae of bloodsucking insects. The method includes treatment of insects habitats with a plant-based insecticide agent. The insecticide agent is a concentrate of margosa or neem seeds oil emulsion. The emulsion contains azadirachtin A and a plant-based emulsifier. The preparation is used as a stable aqueous emulsion.

EFFECT: invention provides for safety of usage, selectivity of action and no addiction of insects to the preparation.

2 tbl, 3 ex

Description

The invention relates to medical entomology, and in particular to methods of controlling disease vectors - mosquitoes.

Participation in the spread of dangerous diseases, the discomfort for a person created by blood-sucking mosquitoes, their high environmental plasticity determine the increased interest and constant attention of researchers to this group of insects, forcing to increase the variety of methods for controlling their numbers.

Currently, the main means of combating the larvae of blood-sucking insects remains chemical insecticides, to which insects quickly develop resistance, which requires either an increase in dosages or rotation of insecticides. Lacking selectivity of action, chemical insecticides cause the death of non-target, beneficial organisms. The accumulation of insecticides in natural components (water, soil, etc.) makes them environmentally hazardous.

Known methods for the destruction of larvae, involving the introduction of insecticides into a pond. The disadvantage of this group of methods is the presence of risks associated with the use of highly toxic substances, as well as the formation of resistance of larvae to toxins. Therefore, their use is recommended only on condition that in other ways the problem cannot be solved.

Known methods for the destruction of larvae using their natural enemies and parasites. The disadvantage of this group of methods is the high complexity, complexity and cost of events.

There are also known methods of killing larvae using bacterial toxins, which are characterized by high selectivity of action, namely: methods of combating mosquito larvae using bacterial insecticides based on the entomopathogenic bacteria Bacillus thuringiensis H-14 (bactulicide, larviol, bactarvaricide, biolarvicide, tecnar, vectobact) Bacillus sphaericus (spherolarvicide, spherix). The main advantage of bacterial insecticides when compared with chemical ones is the selectivity of action. The use of biological products is an environmentally friendly method of combating blood-sucking insects.

The main disadvantages of bacterial insecticides include the relatively short residual effect, the high cost of drugs, the variability of their target properties, inefficiency in relation to pupae (because they do not feed) and, as in the case of chemical toxicants, the emergence of mosquito resistance to to these drugs. Nevertheless, the use of rotation of numerous forms of chemical and biological insecticides in combination with prophylactic methods allows to some extent control the number of mosquitoes in epidemic hazardous areas.

A known method of destroying larvae and pupae of mosquitoes with asphyxia, including isolating the surface of the reservoir from the atmosphere with oily liquids, as a result of which the spit of the larva is clogged with an oily liquid, and the larvae die from oxygen starvation (How to prevent the incidence of malaria? Http://www.med.kg/News / 2005/7 /). In this method, mainly mechanical asphyxiation is used. The disadvantage of this method is the pollution of the reservoir with oily substances, significantly exceeding the maximum permissible concentration according to sanitary and environmental standards, and the high complexity of the full treatment of the treated reservoir from this pollution after achieving the goals of disinfestation.

The other closest to the above is a method of destroying mosquito larvae, which includes temporarily isolating the surface of the treated reservoir from the atmosphere with a layer of polystyrene foam balls (Cbio.ru, Internet journal “Commercial Biotechnology”, Komari 2005: http: //www.cbio.m /modules/news/article.phpostoryid=588). In this method, larvae and pupae do not have access to atmospheric air and are forced to use only integumentary and gill breathing with oxygen dissolved in water. After its exhaustion, the death of larvae and pupae from asphyxia occurs. Cleaning the surface of a reservoir from solid floating substances after treatment is substantially less expensive than from an oil film and dissolved contaminants.

The disadvantages of the above methods include: a long duration of the procedure, because the time to decrease the concentration of dissolved oxygen is directly proportional to the depth of the reservoir and inversely proportional to the degree of population of the reservoir with hydrobionts, as a result, it usually takes several days to achieve the required pest control efficiency; the need to remove floating contaminants from the surface of the reservoir after completion of the procedure.

The technical task of the invention is to expand the arsenal of environmentally friendly methods of combating blood-sucking insects using non-toxic selective drugs that do not cause insects resistance to these drugs and have a number of advantages.

The technical result is achieved by the fact that in the method of controlling larvae of blood-sucking insects, including treating habitats with an insecticidal agent of plant origin, an Indian emulsion or Neem seed oil emulsion concentrate (Azadirachta indica A.Juss) containing azadirachtin A (azadirachtin A) is used as an insecticidal agent and an emulsifier of plant origin in the following ratio of components, wt.%:

Indian Melia or Nima seed oil emulsion concentrate (azadirachtin A content 3000 ppm) - 75.0%

emulsifier of plant origin 10.0-15.0%

the rest is deionized water,

while the drug is used in the form of a stable aqueous emulsion.

Indian Melia seed oil (Nima) is a selective natural preparation of intestinal action, the entomocidity of which is manifested in a violation of the ability of insects to feed, stop their growth and development, suppress reproduction and ovicidal action. If mosquito larvae enter the digestive canal, the drug causes toxicosis and their subsequent death.

Due to the increase in the number of allergic, infectious and parasitic diseases associated with arthropods, there is a need to create new highly effective biocidal preparations, including insect-acaricides, to control the number of insect and tick populations.

Currently, special attention is paid to compounds of plant origin, for example, vegetable oils obtained from tea tree, eucalyptus, caraway seeds, wormwood, lavender, etc., as well as plant extracts with biocidal properties. One of these plants are nim trees from the Meliaceae family, the biologically active substances of which have been used in medicine, cosmetology, agriculture, etc. over the past decades. At least 6 species of trees from this family contain substances with a pesticidal effect.

Of greatest interest is Azadirachta indica A.Juss or Indian Nimes. This tree is widespread in many countries of Asia and Africa, Central and South America, Australia. Both leaves of the tree and its seeds have a biocidal effect, from which oil is obtained by cold pressing, which has an insecticidal, acaricidal, repellent effect on more than 200 species of various insects and mites, as well as on a number of mold fungi, bacteria and viruses.

Indian nim contains at least 35 biologically active substances with biocidal properties. The main ingredient with insect-acaricidal action is azadirachtin (azadirachtin), which has ovicidal and sterilizing effects, interferes with nutrition, and alters the normal metabolism at different stages of the insect's life, etc.

In our country, the drug “Milbiol” (Hexal AG, Biocur Arzneimittel GmbH, Deutschland) is the best studied and registered drug for controlling the number of pyroglyphid ticks in various rooms.

The tool based on the concentrate of the emulsion of seed oil Melia Indiana or Nima (hereinafter: the tool) is intended for the destruction of larvae of different types of mosquitoes (malarial and non-malarial), as well as rice mosquito in all natural areas and for all types of reservoirs, including fishery, in closed urban reservoirs (basement of residential buildings and buildings for other purposes, fire tanks, etc.).

According to the parameters of acute toxicity in accordance with GOST 12.1.007-76, when introduced into the stomach, the agent belongs to class IV substances that are slightly dangerous to humans and warm-blooded animals, and does not have skin-irritating, allergenic, and sensitizing properties. The product is practically harmless to non-target hydrobionts, most entomophages, bees (B4 toxicity class) and other components of the natural complex, without spatial restriction to water surfaces, without waiting periods, is quickly inactivated in water bodies and under the action of sunlight.

The proposed method is illustrated by examples.

Example 1. Commercially available concentrate of emulsion of seed oil of Indian Melia or Neem (azadirachtin content A 3000 ppm) was mixed with water in various ratios. In 0.5 or 0.5-liter glass or polystyrene cups, 99 ml of tap water that was left to stand for 24 hours and 1 ml of the resulting mixtures were added, into which 100 larvae of the 4th age of insect cultures Culex pipiens molestus or Aedes aegypti were introduced in triplicate. During the experiment, the water temperature was 22-23 ° C. The mortality of larvae was recorded at certain intervals (1, 3, 4, 5, and 24 hours). In each experiment, at least 5 concentrations were used.

Example 2. A mixture of the concentrate of the emulsion of seed oil Melia Indiana or Nimes with water was tested in the conditions of example 1 on the larvae of culture Culex pipiens molestus. The results are shown in table 1.

Table 1 The results of evaluating the insecticidal activity of the concentrate of the emulsion of seed oil Melia Indiana (Nima) for mosquito larvae Culex pipiens molestus (average of 3 values) Larvae of Culex pipiens molestus The concentration of the drug,% Death,% Accounting in an hour one 3 four 5 0,045 0 0 0 0 0,037 0 0 0 0 0,028 51 51 54 54 0.018 72 72 75 76 0.009 81 92 94 one hundred The control 0 0 0 0

Example 3. A mixture of the concentrate of the emulsion of seed oil Melia Indian or Nimes with water was tested in the conditions of example 1 on the larvae of the culture Aedes aegypti. The results are shown in Table 2.

table 2 The results of evaluating the insecticidal activity of the concentrate of the emulsion of seed oil Melia Indiana (Nima) for mosquito larvae Culex pipiens molestus (average of 3 values) The concentration of the drug,% Death,% Accounting in an hour one 3 four 5 0,045 twenty twenty thirty thirty 0,037 twenty twenty thirty 40 0,028 thirty thirty 35 44 0.018 thirty thirty 35 fifty 0.009 fifty 56 84 90 The control 0 0 0 0

As follows from the above data, the preparation obtained according to the claimed invention showed high insect-acaricide efficacy on mosquito larvae Culex pipiens molestus and Aedes aegypti.

The advantages of the proposed method of combating the larvae of blood-sucking insects are also:

- selectivity of action - only dipteran insect larvae are affected;

- lack of addiction of insects to the drug, as a result of which the norm of the drug during use remains unchanged;

- the drug does not cause environmental pollution, including water bodies, does not accumulate in the environment and in agricultural products;

- the drug belongs to the group of substances of low toxicity to humans and warm-blooded animals (hazard class IV); practically harmless for non-target aquatic organisms and other components of the natural complex.

Claims (1)

A method of controlling larvae of blood-sucking insects, including treating habitats with an insecticidal agent of plant origin, characterized in that as an insecticidal agent, an Indian or Neem seed oil emulsion concentrate (Azadirachta indica A.Juss) containing azadirachtin A (azadirachtin A) and an emulsifier is used plant origin in the following ratio of components, wt.%:
Indian or Nimes seed oil emulsion concentrate (azadirachtin A 3000 ppm) 75.0 plant emulsifier 10.0-15.0 deionized water rest,
while the drug is used in the form of a stable aqueous emulsion.