Application of encarsia parasite against types

The main direction of obtaining a clean ecological product in agriculture is the biological properties of the soil, the management of the life of living organisms in it, the number and quality of soil organisms, the stability of their populations and the organization of agro-technical measures, biological management. In the 1980s, S.A. Alimukhamedov and B.P. The Adashkevichs brought the whitefly parasite Enkarsia and erythromycin to our homeland from Israel and propagated it in greenhouses. Later, these parasites spread to greenhouses in Tashkent region and cotton fields in Khorezm region. The importance of the parasites mentioned above is enormous today.

Much of the evidence proven in practice in strategic plant protection requires less use of pesticides in protecting crops from pests. In particular, about 900 biolaboratories and bio-factories have been set up in Uzbekistan for the mass reproduction of trichogramma, bracon, enkarsia, pseudophicus and other productive entomophagous and their control against pests of cotton, vegetables and other agricultural crops. lib, systematic control of crop fields not only drastically reduced the amount of pesticides applied, but even limited the use of insecticides in some areas. Natural ecosystems are free of pests and weeds. Even agrocenoses have more beneficial species than harmful ones. Therefore, it is important not to reduce the number of species that control the natural state, but to keep their population stable. It should be noted that the biological method is not useful if the biological method is applied to the area where it is used, and the areas close to it are treated with pesticides.

Enkarsia is a small bee. Its body length usually does not exceed 6 millimeters. In men, the head and chest are black, in women the abdomen is painted light yellow. The reproductive model of these insects is parthenogenesis, in which female gametes develop without fertilization, so males make up more than two percent of the total population and appear only with a sharp deterioration in weather conditions. Under favorable conditions, the total duration of development of the insect is about two weeks, but when the air temperature drops to + 18 ° C, it can be delayed up to a month. Enkarsia is excreted every 2 weeks in the form of infected pupae at a rate of 5-6 pieces / 2m and 10-15 pieces / 2m for pest control. Environmental conditions: Optimal environmental conditions for entomophagous: air humidity up to 60-70%, temperature 26-29 ° C. At temperatures above 30 ° C or humidity above 90%, the productivity and survival rate of entomophagus decreases. The lowest temperature limit for the use of a parasitoid ditch is 13–14 ° C, but with a decrease to 17 ° C, Encarsia search activity is significantly reduced.

The main method of reproduction in encarche is parthenogenesis; males (usually about 2% of the total population) appear only under the influence of low temperatures during development. The female lays about 10-15 eggs per day in the bodies of whiteflies and pupae. The developmental duration of encarcation from egg to imago is 15 days at 26 ° C and 32 days at 18 ° C. Infected pupae darken or appear black spots on the dorsal side, making it easier to monitor entomophagous and assess the level of pest control. Adults emerge from infected pupariums. The bee also feeds on hemolymph of honey and algae larvae, piercing them with ovaries. Encaria is able to find prey at a distance of 15-20 meters. Too much honey can interfere with the movement of the entomophagous. The effectiveness of the use of Enkarsia is affected by the duration of daylight hours (preferably 16-18 hours), brightness of light (7 thousand lux and more), humidity and temperature in the greenhouse.

Entomophagous culture does not tolerate treatment with insecticides of the pyrethroid group. Every year, with the onset of the spring-summer season, many insect pests wake up and begin to live an active life. Nowadays, due to the deterioration of the ecological situation, agricultural plant growers are trying to use biological means of protection, and for this purpose are increasingly using useful representatives of the animal world. Entomophagy is characteristic of a large number of insects that use pests as a food source for their offspring as a phenomenon of their own consumption, thereby limiting their reproduction.The method allows to avoid pollution of the environment, as these plants are treated with pesticides and do not cause dependence on pests.

One of the most striking representatives of entomophagous is the encarsia bee (lat. Ecarsia formosa Gah.) - a parasitoid insect that destroys the population of white larvae that damage flowers, ornamental plants and vegetables (especially tomatoes and cucumbers), so it can The pincha is used in greenhouses, greenhouses and greenhouses.The adult insect (imago) feeds on honey and the hemolymph of the larva, which is perforated by its ovipositor (hemolymph is a fluid that circulates in the internal vessels and intercellular spaces of the “host insect”). During the day, one female of the parasite is able to lay 10 to 15 embryos larvae in the body and pupae (pseudococci) and lays 60 to 100 eggs in just one season. From the embryo of the encarche develops a larva, which pupates inside the shell of the host. As a result, the pupae that infect the entomophagous embryo darken, which allows immediate detection of larvae infected with the parasite. The ideal conditions for the reproduction of these entomophagous - the ambient temperature is +28 ° C, relative humidity is 70% and the length of the day is 16-18 hours. It should be borne in mind that when the air temperature in the greenhouse is above +30 ° C and the humidity level exceeds 90%, as well as when it drops to +14 ° C, the activity of the enkaria and its survival rate decreases sharply. It is worth noting that adult insects (imago) can find white larvae at a distance of up to 20 meters.In this case, mainly the third and fourth drops of the pest are infected with pupae.

Regarding the question of how to control encarcation, I think the following should be done: When the adult whitefly population is first found in fields and greenhouses, when the number of adult pests (imago) is still low, encarcation can be started a week before planting . In case of severe infection, entomophagous puppets should be placed in beds every two or three meters, so that their total number per square meter should be at least three to five.

If the infection of whitefly larvae in the field or greenhouse accounts for about 40% of the total population of the pest, the introduction of encarcation should be considered successful. If, after the parasites are activated, the greenhouse infection remains high enough (more than 70% of the larvae have never been infected by the ensar), observe the ratio of ten to fifteen white larvae of one parasite at the start of the next flight. need Such a model of access provides complete control over the pest during the growing season.A more successful spread of this entomophagous is facilitated by a sufficiently high temperature inside the room, good lighting of the greenhouse, timely detection of infectious foci, and speed of response to the mass appearance of pests. As a natural cousin of whiteflies, we can mention mainly specialized parasites Encarsia (Encarsia form osa).

"Экономика и социум" №12(79) 2020