Order Psocoptera—Booklice and Psocids 
Booklice and psocids are small, soft-bodied, winged or wingless insects, usually 
less than 6 mm long. The more typical psocids have well-developed wings and bear 
a striking resemblance to aphids of the order Homoptera. The wings are held 
rootlike and almost vertically over the body while at rest. Booklice are either 
wingless or possess only vestigial wings, and are about | mm long. 
Psocids are found under stones, on or under the bark and on the foliage of trees or 
shrubs. They are not injurious to trees but they may be a nuisance, especially when 
they occur in large numbers around residences or in recreational areas. They feed 
on fungi, lichens, and probably other vegetable matter. 
Booklice occur most commonly in damp, dark rooms not generally used. They 
are occasionally found in old books, where they feed on the paste of the bindings. 
Sometimes they are abundant enough to cause serious damage. 
Order Mallophaga—Chewing Lice 
Chewing lice are all external parasites of birds and animals. The adults are small, 
usually flattened, and wingless. They feed on the feathers, hairs, or skin of their 
hosts. None is known to attack people. The order is divided into four families. 
Members of the family Trichodestidae attack various species of domestic animals, 
Gyropdidae feed on rodents, and the other two—Menoponidae and Philop- 
teridae—feed on birds and poultry. 
Order Anoplura—Sucking Lice 
Sucking lice are small, wingless insects that live on the skin of various mammals 
and suck their blood. Their bodies are flattened, the mouth parts consist of piercing 
stylets, and there is a rostrum with many tiny hooks at the front of the head. The 
tarsus consists of a single large claw. This claw is opposed by a toothed projection 
on the tibia. The body louse, Pediculus humanus humanus L., and the crab louse, 
Pthirus pubis (L.), attack humans, and a number of other species attack various 
kinds of livestock and other animals. Published treatments of the order (390, 4/0) 
are available, as are discussions on control of species attacking people (2/9, 370). 
Order Thysanoptera—Thrips 
Thrips are small slender-bodied insects, usually from 0.05 to 5.0 mm long. 
Adults are either wingless or have four long, narrow, fringed wings with few or no 
veins. The mouth parts are of the rasping, sucking type; the antennae are usually 
short and 6- to 10-segmented; the tarsi are 1- to 2-segmented, with one or two 
claws, and are bladderlike at the tip. 
Thrips are frequently extremely abundant on flowers. Others occur on foliage, 
fruit, bark, fungi, and in debris. A number of species cause considerable damage to 
cultivated plants, but only a few have been reported injurious to trees (38). 
Liothrips umbripennis (Hood) is sometimes abundant enough on chestnut oak to 
cause the curling of leaves. The slash pine flower thrips, Gnophothrips fuscus 
(Morgan), was first reported as damaging to pine seedlings in nurseries in New 
York and Rhode Island and to jack pine on rocky slopes in Ontario. It is known as a 
serious seed orchard pest of slash pine in Florida and southern Georgia (356, 547). 
It infests the female flower buds, flowers, and very young conelets, puncturing and 
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