construct cases of silk, or frass and silk, and feed from inside them; at least one is a 
predator of scale insects; and many feed as borers in shoots, bark, roots, cones, 
nuts, or fruits. Members of the subfamily are rather difficult to identify because of 
the variability of many of their distinguishing characters. 
The pecan leaf casebearer, Acrobasis juglandis (LeBaron), occurs from south- 
ern Canada to Florida and Texas, and the larvae feed on the buds, flowers, and 
leaves of walnut, butternut, and pecan. The adult is a grayish-brown moth with the 
forewings black at the middle of the costa and reddish-brown near the middle of the 
inner margin, a black raised-scale ridge is also present on the forewings, and the 
head and thorax of the male are distinctly white above. Wingspread is 14 to 17 mm. 
Full-grown larvae are mostly olive green to dark olive green and about 16 mm long. 
The larvae feed during two growing seasons. The first summer, they feed on the 
lower surfaces of leaves. They spend the winter in small cases attached to buds or 
twigs. The following spring, they resume their feeding by eating into bud after bud 
and constructing new cases as necessary. When the larvae become about half 
grown, they move onto the underside of the rachis. The rachis and base of the 
adjacent leaflets are notched and a tube of silk is formed and fastened to the notch in 
the rachis. The leaflets are pulled down about the silk tube and eaten. This, plus the 
injury to the buds, often results in serious damage to infested trees (454, 927). 
Acrobasis caryivorella Ragonot occurs in southern Canada and throughout the 
Eastern United States and the larvae feed on the foliage of hickory, walnut, and 
pecan. The forewings of the adult are black with indistinct patches of gray; a black 
raised-scale ridge is also present on the forewings. The wingspread is about 20 mm. 
The larvae are purplish green and about 19 mm long. In the spring, they feed by 
boring into new shoots that they tie together with silken threads. Full-grown larvae 
construct oval cocoons in which they pupate. Several generations occur each year. 
Generations occurring after the spring generation feed on silked-together leaflets. 
In Florida and Texas, there are probably three or four generations per year. This 
species has seriously damaged pecan seedlings in nurseries in Florida and Texas. 
The pecan nut casebearer, A. nuxvorella Neunzig, occurs from North Carolina 
and southern Illinois to Florida and Texas. Its host tree is pecan (920). The adult is 
mostly dark brown with a dark-brown raised-scale ridge on the forewings, and has a 
wingspread of 12 to 19 mm. Mature larvae are mostly purplish brown with greenish 
undertones and are about !2 mm long. Winter is spent in the larval stage in a small 
case near the base of a bud. Later, larvae bore into tender shoots, causing them to 
become stunted and distorted. Larvae of the second generation bore into newly set 
nuts, destroying from two to five nuts each. Larvae of later generations feed in the 
large nuts or on the shucks. There are three or four generations per year in the 
South. 
Many other species of Acrobasis occur on forest and shade trees in the Eastern 
United States. The birch tubemaker, A. betule/la Hulst, is common, feeding on 
the foliage of various species of birch, particularly paper birch in the Northern 
United States and southern Canada; A. betulivorella Neunzig occurs on river birch 
in the Southeastern United States; A. rubrifasciella Packard, the alder tubemaker, 
feeds on foliage of alder; A. indigenella (Zeller), the leaf crumpler, is associated 
with hawthorn foliage; A. demotella Grote, the walnut shoot moth, bores in shoots 
of walnut, hickory, and pecan; A. exsulella (Zeller) occurs in buds and between 
leaves of hickory and pecan; A. e/yi Neunzig bores into, and galls, the rachis of 
hickory leaves; A. carpinivorella Neunzig feeds on the leaves of American 
181 
