232 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 
trunk are almost equally efficacious. Care and attention, and, above all, 
00 operation among those suffering from these worms, will enable us to 
check their ravages. 
14. The rlm span-worm. 
Eugonia tubsignaria (Htibnei }. 
Order LbPIDOPTKBA J Family PlIAUENID.fi. 
Hatching from the eggs as soon as the leaves unfold and living unobserved for a 
week or two on young shoots in the tree tops, measuring or span worms, resembling 
the twigs of the elm in color, with a large red head, and the terminal ring of the body 
bright red ; pupating towards the end of June, and during July and August trans- 
forming into a snow-white moth. 
This insect is widely spread. I have 
observed it in the forests of northern 
.Maine in August, and it is common in 
the Middle States. It is very destruc- 
tive to the elms in New York City, 
Brooklyn, and Philadelphia, though not 
known to be destructive in the country. 
The moth may at once be recognized by 
the snow-white body and wings, the an- 
terior pair being angular and the hinder 
pair slightly notched. It is, according 
to Fitch, still more destructive to the 
linden than to the elm. 
From a pamphlet by H. A. Graei and 
Edw. Wiebe, entitled u The measure- 
worm, a description of the insect, in all 
its metamorphoses, etc/' (Brooklyn, 1862), we quote the following facts : 
The eggs are deposited by the female moth toward the beginning of July, not only 
on trunks and branches of early-leaving trees, but also on numerous other objects, to 
the number of from 20 to 250, in irregular clusters. During this period they are about 
the size of a small pin's head, conical in form, and somewhat compressed at their 
points; first of a yellowish, then of a light olive green, and later of a dark brown. 
They are covered with a thick, sticky glutinous matter and adhere strongly to the 
object on which they are deposited. They are usually found on the under side of 
branches, and almost always below the connecting points of the same, apparently for 
their better protection and with the design of opening several avenues for the young 
brood to find subsistence. The number of eggs generally decreases from the base of 
the branches towards their extremities. » 
In this state the eggs remain unaffected by rain or frost, seemingly unchanged, 
until the time when our shade trees unfold their first leaflets, which (subject to the 
weather) is usually between the 15th of April and the loth of May. 
Little caterpillars then creep from these eggs, eagerly enjoying the rays of the 
sun on warm days, and carefully hiding themselves under the young foliage for pro- 
tection on cold and stormy days. Here we rind them crowding together in countless 
numbers; until after a very brief period they engage in their work of destruction. 
The young caterpillars always creep towards the extremities of the branches, led by 
Fin. 70. — Elm span-worm niotli. natural 
size. — After Emerton, from Packard. 
Flo 
. — Elm spau-worm. natural size.— 
After Emerton, from Packard. 
