which they hang head down. Some, such as those of the families Papilionidae and 
Pieridae, are girdled with a strand of silk and do not hang head down. Skippers 
pupate in cocoons made of leaves fastened together with silk. 
The order Lepidoptera contains numerous destructive forest and shade tree 
insects. Several species such as the spruce budworm, the forest tent caterpillar, and 
the gypsy moth often occur in outbreaks covering tens of thousands of hectares of 
woodlands, and losses are very great. Large volumes of timber may be killed, and 
larger volumes are lost through reduced growth of surviving trees. Many other 
Species cause serious losses by boring into and destroying the buds and shoots of 
seedlings and young trees in forest nurseries and plantations, or by mining the 
tissues between the upper and lower surfaces of leaves. The attractiveness of shade 
trees, parks, and other recreational areas is often reduced or destroyed by these 
insects, fire danger is increased, and wildlife habitats are impaired. 
The literature on these insects is vast, and the references given here for further 
treatment are few, but selected because of their broad coverage (/40, 16/7, 318, 352, 
374, 413, 433, 440, 447, 575, 586, 587, 614, 672, 785, 865, 1002, 1003, 1004, 
1007, 1204). 
Family Eriocraniidae 
Eriocraniids 
Larvae of the very small species Dyseriocrania auricyanea (Walsingham) mine 
the leaves of oak, chestnut, and chinkapin in the Eastern States. The mines are often 
blotchlike and may encompass up to one-fourth of the leaf area. Damage is 
sometimes a matter of concern to owners of Asiatic chestnut orchards. 
Family Hepialidae 
Hepialid Moths 
Hepialid moths sometimes attract attention late in the day when they are seen 
flying swiftly in a zigzag manner, close to the ground. They are medium to large in 
size, with rather long, stout abdomens and a wingspread of 25 to 100 mm. The 
better known species are yellowish to brown or ashy gray with silvery-white spots 
on the wings. The larvae are long-headed and nearly naked, have five pairs of 
prolegs, and normally live as root borers. Sthenopis argenteomaculatus (Harris) 
breeds in the base of the trunk and roots of alder in the Northeastern States: S. thule 
(Strecker) breeds in the roots of willow. 
Family Nepticulidae 
Nepticulids 
This family includes the smallest of the Lepidoptera, the adults of some species 
having wingspreads of only 3 mm. Because of their minute size, their retiring 
habits, and their irregular flight, they are seldom seen. The larvae of most species 
are leafminers: a few construct mines in the bark of their hosts. Many of the more 
common deciduous trees in the Eastern United States serve as hosts for one or more 
species. The larvae are slightly flattened, and their heads are rather deeply retracted 
into the prothorax. When full grown, the majority vacate their mines, drop to the 
ground, and spin dense, flattened cocoons in the duff (/47). 
The genus Neprticula contains many leafmining species. Eggs are deposited on 
either surface of a leaf, usually along the side of a vein. The larvae of certain species 
mine only one side of a leaf; some mine both sides; and some mine different sides at 
different periods of larval life. The mines may be linear and gradually widen as they 
are extended, or, at some point, they may enlarge suddenly into a blotch. Winter is 
spent in the larval stage. There are one to four generations per year, depending on 
the species. 
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