بررسی بیواکولوژی شته راش

Beech aphid (Phyllaphisfagi); Order: Homoptera; Superfamily:Aphidoidea ; Family:Callaphididae ; This aphid complete its life cycle on a single host plant (beech tree ). Th~ insect is 2-3 mm long ., with a green to light yellow coloration and with waxy secretions which accourt as the best macro scopic characteristic to identify the aphid. A wast sampeling measures have been done on beech forest trees and associated under-story plant across northern parts of the country from Ardabil and Astara through Golestan Province.The investigation on life cycle of this aphid in beech forests indicates ,that this insect lives on beech trees throgh feeding on plant tissues cause extensive damage especially to young trees. Apid over crowing results in leaves and twigs and twisting and terminal shoots death. Four speecies of ladybird , one assasian bug, and one specie of Chrysopa are among the main natural enemies . But these spcies seems to have less potential as an agent of biological control, but conversely abiotic factors such as high temperature, low humidity as wee I as heavy spring rains inhibit the development and have a major role on decreasing aphid population