Bioecology of Psylla Pyricola Foerster and Methods of Its Management

Abstract

Biological characteristics of the pear psylla in Uzbekistan conditions are highlighted in the current paper. Yield losses due to this pest as well as its natural enemies that regulate pest numbers have been studied. The most frequent species among beneficials belonged to coccinellids (55% of total beneficials) and chrysopids (25%). It has become known that even all the natural enemies of pear psylla altogether could not regulate density of the pest. So, each of unprotected with insecticides trees has lost up to 65 kgs of fruit yields compared with treated ones. Pear psylla has started its development in early March in conditions of 2016. Its numbers have reached a maximum by July to August, and then began to decrease. Adult psylla individuals started to prepare themselves for overwintering in October to November. There were no clear limits between separate (5 to 6) generations, so individuals of various generations could be seen at the time.

Coccinellids have been the most frequent amongst beneficials and dominant species of them was twin spot Adalia and seven spotladybirds (55% of total enemies of the psylla). These have appeared in April and their numbers have decreased sharply after October.