Homoptera - apple pests in forest communities of Fergana valley, Uzbekistan

. This article presents the results of the study of apple’s homoptera pests in the forest communities of Fergana Valley, biological features, harmfulness, features of development phases, specific composition of the most harmful species, food relations, their natural enemies and recommended measures to control them. Species that are a component of entomocenoses of cultural and natural landscapes of Fergana Valley, their negative impact on forest communities have been established. It was revealed that the species of homoptera insects, in particular cicadas, in Fergana Valley are characterized by complex bioecological features, highly specialized and adapted for habitation. The research is of theoretical and practical importance, since many species are pests and some species carry viral diseases. The Auchenorryncha pest series is distinguished by diversity in species composition and amount. The pest Cicadatra querula (Pall.) breeds in mass numbers in some years. The nature of the damage caused by C. querula (Pall.) was studied, since insects suck plant juices and damage fruit and shrub plants when they lay eggs. It has been established that the terms of cicada passage of the development phases depend on temperature and humidity.


Introduction
The importance of studying forest pests and the role of protecting forests and forest plantations are especially significant at the present time. Many researchers A.Sh. Khamraev, D. Abdullaeva, Sh. Komilova, A.Kh. Kuchkarov, Z.O. Bekbergenova, and A.G. Kozhevnikova note that in recent years there has been an expansion of habitats and an increase in the harmfulness of various pests [1][2][3][4].
The fauna of Homoptera insects are presented by sucking insects with a complex and peculiar bioecology, the degree of their study is still insufficient [5]. We noted that dangerous pests of apple trees and other plants in forest communities belong to various groups of insects. We studied cicadas (series Auchenorrhyncha) belonging to Homoptera insects order.
According to Professor A.A. Zakhvatkin in Central Asia, forest species are harmed by 7 species and 2 subspecies of cicadas [6]. After 15 years, it is reported that, according to Professor G.K. Dubovsky in Central Asia, forest species are harmed by more than 30 species of cicadas [7]. The same researcher notes: "From this group of insects, species new to science and even new generations are being discovered and described, including species that are pests." Fergana Valley, where we conducted our research works, is characterized by a large amount of heat, which ensures the growing of many cultivated and wild trees and shrubs.
Four main zones are distinguished in Fergana Valley: central, adyr, foothill and High Mountain. The high-mountain zone is represented by powerful ridges framing Fergana Valley. The foothill zone is well introduced in the lower band of mountains that form Fergana basin. The adyr zone is located between the central flat part and the foothills of Fergana basin. The main areas of cultivated land are concentrated in the central part of the valley [8][9][10].
Among the homoptera insects, cicadas occupy a special place; it is ecologically associated with various biotopes and plays an important role in agrobiocenoses. Entomological studies of these insects are ongoing. However, there is little literature on this issue. As a result of cycads nutrition, plant development is often disturbed, accompanied by various deformations and even death of separate parts of plants.
It is necessary to take into account the emergence of pests, the study of their species composition, peculiarities of development, distribution, and their natural enemies in order to develop modern approaches to protecting plants from pests.

Materials and methods
Fergana Valley is divided into four distinct areas: the center, adyr, foothill, and high mountain. The strong ridges that surround Fergana Valley serve as a representation of the high-mountain zone. In the lower band of mountains that make up the Fergana basin, the foothill zone is firmly established. The adyr zone is situated between the Fergana basin's foothills and middle flat region. The center region of the valley contains the majority of the valley's agricultural land. The material for this work was 10 years of research conducted in Fergana Valley of Uzbekistan. Common in entomology and special techniques were used.
Stationary and route collections, observations, experiments and calculations were carried out. When studying the biology of individual species, cages, cоvers and insulators were used. We used the same method in raising larvae with the purpose to breed adult insects (imago) for accurate diagnosis of the species.
Edwardsiana rozae L. sucks plant juices on the underside, small light spots form on the upper side. Therefore, leaves damaged by Edwardsiana rozae L. acquire a marbled appearance.
In Fergana Valley, it was found on wild and cultivated apple trees. Edwardsiana rozae L. feeds on them from the beginning of March to the end of October. But there exists one more species evoking the marble appearance of the leaves with its nutrition. It is Linnavuoriana malicola Zachv. In Fergana Valley, the species Linnavuoriana malicola Zachv. occurs on wild and cultivated apple trees, damaging them. Erythroneura amseli Dlab. and Cicadella viridis L., damage apple trees and dog rose. In addition, Cicadella viridis L. selects these plants for oviposition and lays eggs under the bark. Cicadatra querula (Pall.) is a numerous and widespread species in Uzbekistan (Figure 1).

Fig. 1. Cicadatra querula (Pall.) is a pest of apple trees.
This species has an extensive range. In Fergana Valley, it is typical for the foothills, where a high number of cicadas is observed. In Fergana Valley at an altitude of 1400-1700 meters, single individuals of Cicadatra querula (Pall.) appear at the beginning of the first ten days of June, the mass flying continues until the end of June and August.
Mass egg-laying continues from the third decade of June to the end of August. Cicadatra querula (Pall.) for oviposition makes cuts up to 4-5 mm long on tree branches and young twigs, usually up to 6-7 mm thick. When laying in forest plantations, Cicadatra querula (Pall.) chooses certain species, prefers poplar, in plantations of apple trees and other trees, it lays eggs in succession.
Cicadas lay their eggs in pre-prepared chambers of 1-15 eggs. Branches and twigs above the locations of the cameras die by autumn or by the coming spring. This is one of the harmful aspects of Cicadatra querula (Pall.). Larvae of Cicadatra querula (Pall.) develop in the soil, feeding on plants sap. Since the larvae develop in the soil, the number of exit holes in the soil gives an idea of the number of adults (imago), numbering up to 25-30 specimens per 1 square meter.
A mature nymph crawls out of the soil and is placed on branches at a height of 25-35 cm. Then the nymph turns into an imago. Males of Cicadatra querula (Pall.) are capable of chirring or singing. At the end of June, females lay their eggs. In total, the number of eggs laid by one female reaches from 100 to 200 specimens.
Oviposition and the mating period preceding it are observed at the end of the day or in the morning, which is connected with temperature and humidity. To establish the period of oviposition, systematic dissections of females, which were collected in nature, were made.
By the beginning of formation and maturation of eggs, one can judge the beginning of oviposition in nature, and a decrease in the number or absence of eggs in dissected females may indicate to the end of oviposition.  Table 2. That by the beginning of egg formation and maturation, one can judge the beginning of egg laying in nature (June 30, 2021), and a decrease in the number or absence of eggs in the locks being opened indicates the end of egg laying (July 31, 2021). In parallel with this, observations of oviposition were carried out in cages. In addition, the collection of cicadas was carried out when examining the upper soil layer under the plants. The appearance of larvae is observed at the end of August. First, the larvae are on the branches of tree and shrub vegetation, then fall to the ground and penetrate into the soil.
In the soil, the larvae break through passages and arrange chambers where the roots of plants exist and pass. The size and shape of underground passages depends on the age of the larvae, which have five instars. From the roots of plants located in chambers and passages, the larvae suck out plant juices, thereby causing damage to them.
With mass reproduction Cicadatra querula (Pall.) can cause significant damage to fruit and tree-shrub plants in the forest communities of Fergana Valley. On the plains of Fergana Valley, we noted damages by cicadas to apple, pear, poplar, grapevine and other crops.
Diagnosis of cicadas is carried out, first of all, according to the structure of the male genital apparatus (Figure 2). Cicadas are attacked by natural enemies, reducing their numbers. The predator of the cicada Cicadatra querula (Pall.) is the predatory fly Satanas gigas (order Diptera). These insects are destroyed by reptiles: Turkestan agama, steppe agama, reticulated roundhead, sandy roundhead. Various birds of the local fauna feed on cicadas: field sparrows, minahs, long-tailed shrikes, dark-throated thrushes, magpies, swallows and others. Hymenoptera from the Dryinidae family turned out to be the most effective parasites of cicadas. Infection by them reached up to 17%. The following species dominated: Gonotopus septoides, G. formicarius.
The obtained results of the research indicate that the study and identification of insects from the order Homoptera, their morphological, biological, ecological features, harmfulness, peculiarities of developmental phases, behavior, biology, their natural enemies, have practical importance for the organization of modern, promising and environmentally friendly protection of plants from harmful species.

Conclusions
To study the number of cicadas and development the basics of protective measures taken in Fergana Valley, it is necessary to determine the species composition of cicadas, determine whether they are pests, or are they neutral species, their diagnostics, study of harmfulness, biological, environmental characteristics, development dynamics, determination of the economic threshold of harmfulness, as well as the impact on biocenotic processes in specific communities.
The study of entomophages of cicadas' dominant species showed that cicadas are destroyed by predatory and parasitic animals. The obtained results of the research indicate that the study and identification of insects from the order Homoptera have practical importance for the organization of modern and environmentally friendly plant protection from harmful species.