Advice
RHS Help & Advice
Pear pests
A range of pests can affect pears, but few cause real problems
Pear trees can be attacked by grey aphids (pear bedstraw aphid) and winter moth caterpillars in spring. The ripening fruits are sometimes damaged by codling moth caterpillars, wasps and birds. The most troublesome pests, however, are pear fruitlet gall midge and pear leaf blister mite.
Pear fruitlet gall midge
Pear fruitlet gall midge is a tiny fly that lays eggs on the unopened flower buds. The orange-white maggots are up to 3mm long and feed inside the young fruitlets. Affected fruitlets become abnormally enlarged and blacken from the eye end. Large numbers of fruitlets drop from the tree in late May to June, when the maggots go into the soil to pupate.
Pear leaf blister mite
Microscopic in size, pear leaf blister mite lives within the foliage. In spring, new foliage develops pink or pale green blotches that gradually become brownish black (below).
Control
Several generations occur during summer, giving the tree an unhealthy appearance, although it seems to have little effect on overall vigour and the fruit is not affected. There are no effective pesticides for garden use. On lightly infested trees, remove affected leaves or shoots in the spring to prevent further spread.