Psyllidae

Psyllids are 2-5 mm long and resemble very small cicadas or aphids; the adults have stout legs and the hind pair are large, and for jumping. Adults are very active and jump or fly when disturbed. Nymphs of some species are covered with waxy material; others are concealed in galls on plant leaves. All species feed on plant sap. The pest status of these insects is shortlived and limited to the presence oflarge numbers ofadults in fall or spring around the outside of houses. They do not infest houseplants.

Hackberry trees (Celtis) grow in a variety of soil types and are often planted as ornamental shade trees; the most common is C. occidentalis. These trees are attacked by many gall-forming psyllids, all of which belong to the genus Pachypsylla. Although the hackberry tree is cosmopolitan, Pachypsylla only occurs inNorth America. These insects are divided into species groups that form galls on leaves, and those that form galls on woody portions of the plant. Adults of the forms that cause wood-gall emerge in the spring. Adults of the leaf-gall forms emerge in the fall and overwinter; large numbers collect on windows, window screens, and doors in fall. Species in the chalcid genera Psyllaephalgus and Torymus are predaceous on Pachypsylla larvae in leaf galls. Predation rates range from 30 to 50%.

Blister-gall psyllid, Pachypsylla celtidisvesicula Adults are about 4 mm long and brownish green or black; wings are translucent. Adults emerge from overwintering sites and become active when the leaves of the host tree develop. Eggs are laid singly on leaves; hatching occurs in 7-10 days. Feeding by the immature stages stimulates the development of a blister-like gall on the top surface of the leaf; there is one psyllid nymph per gall. Development is completed and adults emerge in September and October. Prior to finding an overwintering harborage, large numbers ofadults can occur on buildings close to hackberry trees. This species occurs primarily in eastern and midwestern USA.

Hackberry nipple-gall psyllid, Pachypsylla celtidismamma

Adults are about 4 mm long and brownish green or black; wings are translucent. Adults emerge from overwintering sites and become active when the leaves of the host tree begin to develop. Eggs are laid singly on leaves; hatching occurs in 7-10 days. Feeding by the immature stages stimulates the development of a cylindrical gall about 6 mm high on the underside of the leaf; there is one psyllid nymph per gall. Development is completed and adults emerge in September and October. Large numbers of adults can occur on buildings close to hackberry trees. This species occurs primarily in eastern and midwestern USA.

Other Pachypsylla The hackberry twig gall-maker, P. venusta, deforms small twigs. The adults of this species may occur in large numbers outside buildings.

The Best Home Remedies For Head Lice

The Best Home Remedies For Head Lice

Discover The Best All Natural, Inexpensive Home Remedies For Treating and Preventing Head Lice No Matter How Severe The Case.

Get My Free Ebook


Post a comment