Sugar maple, but the larvae also feed on the leaves of red maple, 
beech, birch, elm, and hophornbeam. The adult has long, narrow, 
pointed wings and a wingspread of 814 to 13 mm. The forewings 
are steel blue and fringed with black; the hindwings are pale 
smoky brown, translucent, and bordered with a pale brown fringe 
of long hairs. There is a dense tuft of bright orange-yellow hairs 
on the top of the head, the thorax is steel blue, the legs whitish, 
and the abdomen dark brown. First instar larvae are flattened, 
about 114 mm. long, and they taper from the front to the rear. 
Full-grown larvae are slender, flattened, and usually dull white 
with amber brown heads and a broad longitudinal stripe. They are 
about 6 mm. long. Pupae are light yellow-ish brown, about 5 to 6 
mm. long. Abdominal segments two to eight bear transverse rows 
of short, stiff, backward-pointed spines on the back. 
In Canada, adults appear in the spring about the time the 
leaves open and deposit their eggs singly in pockets on the under- 
sides of the leaves. When the larvae hatch, they bore into the leaf 
tissues and feed as miners for about 10 days to 2 weeks. Then, 
each larva cuts a round dise out of the leaf and makes an oval, 
movable case in which it resides as a casebearer. As it grows, it 
cuts out larger oval pieces and attaches them to its case. In order 
to feed, it attaches the case to a leaf and reaches out from it in a 
circle as far as it can. The uneaten center of this circle often 
drops out, leaving a hole up to 14 inch in diameter in the leaf. 
When the larvae become full-grown, they drop to the ground to 
pupate. Winter is spent in the pupal stage, and there is one gener- 
ation per year (620). 
The maple leaf cutter is often a pest in sugar maple stands, 
especially in sugar maple orchards. The trees may be severely 
defoliated, often for several years in succession. 
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 wingspreads 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 5 pairs of prolegs, and normally live as root borers. Sthen- 
opis argenteomaculatus (Harr.) breeds in the base of the trunk 
and roots of alder in the Northeastern States; S. thule (Stkr.) 
breeds in the roots of willow. 
FAMILY ERIOCRANIIDAE 
Larvae of the very small species, Mnemonica auricyonia 
(Wlsm.), mine the leaves of oak, chestnut, and chinquapin in the 
Eastern States. The mines are often blotch-like and may encom- 
pass up to one-fourth of the leaf area. Damage is sometimes a 
matter of concern to owners of Asiatic chestnut orchards. 
414 
