The adults of both sexes usually overwinter beneath the outer bud scales and become active in the early spring when the buds then start to swell . At this time they burrow deeper into the buds and start to feed and lay eggs at the base of the inner scales of the bud. This is the time for winter was, but it can difficult.
Springtime you start seeing damage to the buds. They become active at bud break, migrate to the tender, new leaves, and burrow beneath the epidermis of the undersides of leaves to feed. This results in a gall, or blister, in which the eggs are laid.
Chemical control includes.
Retail products available for use on pear trees – Fatty acids, Doff Universal Bug Killer, Lambda cyhalothrin by Westland and Resolva Bug Killer by RTU.
Commercial products available for use on pear trees – Deltamethrin: Decis and others, Chlorpyrifos: Equity and others, Fatty acids: Savona and others, Lambda-cyhalothrin: Hallmark WZT and others.