LIBRARY

HEMIPTERA 321
large wing pads, and often with a marginal fringe around the body. They may
be naked, hairy or covered with wax and excrete quantities of honeydew.
Some of the species have been imported on ornamentals from foreign countries.
These insects are widely distributed in the temperate regions and are notably
abundant and varied in Australia, where 80 species of these so-called lerp
J
FIG. 109. The tomato or potato psyllid, Paralnoza cockerelli (Sule). A, adult female; B, antennal
segment IV showing peculiar sensorium; C, tarsus; D, egg; E, genitalia of male; F, genitalia
of female; G, nymph; H, marginal fringe of same; I and J, antenna. (From Insects oj
Western North America.)
insects replace the aphids. They often occur in very great numbers on eucalyptus,
acacia, and other native plants. All secrete quantities of honeydew and a
few produce galls on the leaves. The sugar lerp insect, Spondyliaspis eucalypti
Dobson, excretes sufficient amounts of 1erp honey to be collected for food by
the aborigines. The brilliant red Creiis longipennis Walker, 6 mm. long, is one
of the largest Australian species.
The pear psyUa, Psyllia pyricola Forster, 1.5 mm. long, is a serious pest of
pear trees, and the apple sucker, P. mali Schmidberger, attacks apples in
Europe and eastern North America. P. buxi Reaumur forms miniature cabbageshaped
galls on boxwood, and Trz'oza alacris Flor curls the leaves of the laurel
or sweet bay in Europe and other parts of the world where it has been intro·
duced. The nymphs of ,the latter secrete quantities of white cottony wax over
their bodies. The tomato psyUid, Paratrioza cDcker,elli (Sule), is of importance
because it disseminates a disease of potatoes in western North America. The