elm, maple, ash, beech, walnut, oak, chestnut, poplar, willow, apple, pear, and 
plum, but it will attack scores of other species. The female is heavy-bodied and has 
a wingspread of 62 to 75 mm. Full-grown larvae are about 50 mm long. The body is 
usually pale yellow but may have a pinkish tinge. It is aiso sparsely hairy and dotted 
with brown or biack tubercles. 
Adults are present from late spring until fall. Eggs are deposited either singly or 
in small groups in bark crevices. Young larvae bore directly into twigs, branches, or 
the trunk and feed in the heartwood. When a larva becomes too large for a twig or 
branch, it vacates it and migrates to a larger one. As the larva feeds, it pushes chips, 
matted excrement, and frass to the outside through the entrance hole. Pupation 
takes place within the tunnel, and the life cycle requires 2 years (6/2). 
The leopard moth may cause considerable damage to its host. Damaged twigs 
wilt and break off, small branches break and hang down, larger branches are girdled 
(fig. 49) and may break in the wind, and small seedlings are killed. Ugly scars 
appear on the trunks of large trees where the bark dies and splits over wounds. The 
removal and destruction of infested twigs, branches, and heavily infested trees is a 
recommended control practice. Borers in valuable shade trees can be killed by 
probing their tunnels with flexible wires. 
Courtesy Conn. Agric. Exp. Stn. 
Figure 49.—Elm branch nearly severed by larvae of the 
leopard moth, Zeuzera pyrina. 
The pecan carpenterworm, Cossula magnifica (Strecker), occurs throughout 
the Southern States. Its hosts are pecan, oak, and hickory. The adult is grayish with 
brown markings and has a wingspread of 37 mm. Full-grown larvae have pinkish 
bodies sparsely clothed with short, fine hairs and are about 37 mm long. 
Adults appear in May and June and deposit their eggs on the bark of small twigs. 
Newly hatched larvae bore into the twigs and tunnel in the pith. Later, they emerge 
and migrate to larger branches or the trunk where they enter and excavate tunnels up 
to 8 cm long. Frass is extruded through holes that are about 6 mm in diameter in the 
trunk; it can usually be found in small heaps at the base of infested trees. Winter is 
spent in the larval stage, and pupation occurs in the tunnel in the spring. There 
appears to be one generation per year (/35). 
Acossus centerensis (Lintner), the poplar carpenterworm, and A. populi 
(Walker), the aspen carpenterworm., also occur in the Eastern United States. A. 
centerensis bores in poplars from New Jersey to North Dakota. A. populi is found 
sparsely in poplars and cottonwoods from coast to coast. 
The carpenterworm, Prionoxystus robiniae (Peck) (fig. 50), is widely dis- 
tributed in the United States and southern Canada where it breeds in various 
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