This insect was not native to North America, but was accidentally introduced into the northeast in the 1830's. By the 1940's, psylla had spread to all the pear growing regions in the United States. The pear tree is the only plant on which the insect can complete its life cycle. Occasionally, the adult psylla and the egg stage can be found on other hosts, such as on quince trees. The tiny, clear-winged adults look like little cicadas.
Adults are one-eighth of an inch long including wings.
They have brownish bodies, and large, clear, membranous wings that they hold over their bodies like a tent. Pear psylla overwinters as adults, both in and near pear orchards. The adults become active at temperatures between 40 and 50 degrees Fahrenheit. On warm spring days, adults can be found on the trunks, twigs, and branches. When pear fruit buds are swelling in April, psylla adults usually mate and begin egg laying.