Origin:
Native to Europe, but introduced to North America in the early 1800’s where it now is the most important insect pest of pears in the U.S.
Biology:
This psyllid infests only various varieties of pears. Mature adults overwinter, become active and mate in the spring, and move to pear trees to lay eggs on stems and developing foliage. There are normally 3 generations through the warm months, and a 4th generation in the fall which again overwinters. The summer females lay as many as 300 eggs, normally placing them along the midvein of a leaf. As the nymphs feed they exude heavy amounts of honeydew, which accumulates around them and their shed skins to form a sticky mass on the leaves. Damage is caused by loss of foliage, growth of sooty mold on fruit, and vectoring of a pathogen that causes pear decline.
Identification:
The summer form adults are about 2.5 mm in length, and light orange to reddish brown with 4 darker stripes along the back. The wings are clear but with a dark spot along one edge. Winter adult form is very dark brown to black, with darker veins on the wings. Adults resemble aphids, but lack the cornicles aphids have on the top rear of their abdomen. Psyllids’ eyes are more pronounced and the antennae point sideways compared with aphids.
Characteristicts Important to Control:
Since the overwintering adults may not stay on the trees winter dormant oil applications are ineffective. Insecticide applications should be timed for the spring when the adults first begin to lay eggs on the leaves. At this time a light horticultural oil could be used without injury to the new leaves. For commercial growers there are several highly effective predatory insects that may be mass-released.
