500 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
Figure 123.—The leopard moth (Zeuzera pyrina): A, Adult female; B, larva. 
uses in pushing its way partly out of the burrow just prior to the 
emergence of the moth. 
This European species was accidentally introduced into the United 
States sometime prior to 1879. It is well established, and is known 
to occur in the Northeastern States from Philadelphia, Pa., to the 
northern border of Massachusetts. The elms and maples are the 
favored host plants, but many other deciduous trees are also attacked. 
The moths issue from May until late in September. The female de- 
posits her eggs singly or in groups of usually 3 or 4 in crevices on the 
trees. As many as 800 egos may be laid by a single moth. The larva 
hatches in about 10 days “and bores directly into a twig, b ‘ranch, or 
trunk of a deciduous tree, feeding on the living wood. If a larva be- 
comes too large for a branch in which it is feeding it crawls out and 
bores into a larger one. Nearly 2 years are required for the larva to 
complete its gr owth, when it transforms to the pupa within its burrow. 
This usually takes place the second May or June after the larva has 
hatched from the egg. The presence of the borer in a tree is revealed 
by an accumulation of chips, matted excrement, and frass near the 
entrance to the burrow. The leopard moth larva is very injurious. 
The small infested twigs wilt and break off, and often larger, nearly 
severed branches are br ought down by high winds, as in many cases 
the full-grown larva oirdles the branch (fie. 124). Where a large 
larva has worked just under the bark, this splits open the next season 
leaving an ugly scar. 
It is advisable to cut down and immediately burn all heavily in- 
fested trees. When only one or two branches are infested they should 
be cut off well below the parts attacked. In trees of considerable 
value many of the larvae can be killed by inserting a pointed barbed 
