INSECT ENEMIES OF EASTERN FORESTS Sl 
THE PSOCIDS AND BOOKLICE 
ORDER CORRODENTIA 
To the order Corrodentia belong several species of small insects 
with chewing mouth parts and four membranous wings, which when 
present, are held rooflike over the body. = 
The psocids (fig. 7) are often seen in great numbers on the trunks 
of trees where they feed on lichens and the surface of the bark. or 
among the leaf litter on the 
ground. <A species, Archipsocus 
nomas Gurney, is often abundant 
on the trunks of shade trees in 
New Orleans. It completely covers 
the bark with a matlike cobweb. 
The booklice are wingless, whit- 
ish, or grayish-white forms, about 
1mm. long, found in damp corners 
of buildings, musty bulletin cases. 
and bookshelves. They feed on 
molds and other vegetable or 
animal matter. Back (9) stated 
that when they become annoying 
they can be controlled by sprin- 
kling the infested locations with 
powdered sodium fluoride, or bet- 
ter by spraying with DDT. (See 
caution on p. 24.) 
LACEWING FLIES, FISH FLIES, 
ANT LIONS, AND RELATED 
FORMS 
OrpER NEUROPTERA 
The order Neuroptera includes a is 
Cnet ati eeeeerccerial FIGURE 7.—Adult book louse (Liposcelis 
varie y of aqua IC atic erres rla divinitorius (Miill.)), Gommon = in 
insects representing a wide range — dwellings. About 55 X natural size. 
of forms, but all have four mem- 
branous wings (fig. 8) with numerous cross veins, mouth parts fitted 
for chewing, and five-jointed tarsi. They have a complete meta- 
morphosis. 
THE DOBSON FLY AND OTHER FISH FLIES 
Famity SIALIDAE 
The best known representative of the family Sialidae is the Dob- 
sonfly (Corydalus cornutus (1.)) and its larval stage, the hellgram- 
mite(fig. 9). The adult is a large conspicuous insect, sometimes 
nearly 100 mm. in length, with large membranous wings, and a cop- 
spicuous rectangular head and thorax, the former provided with long 
pincers (mandibles) in the male. The larva is equally large, grayish 
black, depressed, with a prominent, rectangular prothorax and head, 
