Leaf-Eating Insect Pests of Ornamental Trees (Coleoptera: Chrysomelidae) and their Bioecological Features

The article describes the results of research on the development, damage and prevalence of poplar leaf beetles (Melosoma populi L. ) and willow leaf beetles (Galerucella luteola) in Tashkent and Khorezm regions of the country. It has been found that the development of poplar and willow leaf beetles depends on the type of trees and the air temperature. The average number was determined in the branches of the trees, in the first generation it was found that the number of beetles increased from an average of 14.2 to 19.3. In the Tashkent region, the total egg-laying period of poplar leaf beetle females increased to the first period of May, and the total flight period of beetles increased to 22.3 in June. The female-male sex ratio of the beetle (males: females) was found to be on average 3: 6. It was found that the development of poplar and willow leaf-beetles populations mainly coincides with the first and second period of May, when the female beetle lays eggs. At the same time, during the development of poplar and willow leaf beetles, it was found a sharp slowdown in the rate of laying eggs and in the feeding of larvae at high temperatures. It was found that 75 % of the leaves of the trees die as a result of the damage of the first generation worms of the willow leaf beetles.