SB 
818 10. 97 Issued February 6, 1908. 
ig aited States Department of Agriculture, 
BUREAU OF ENTOMOLOGY, 
L. O. HOWARD, Entomologist and Chief of Bureau. 
THE BAGWORM. 
( iieaiosioni ephemerxformis Haw. ). 
By L. O. Howarp and F. H. CxHirrenpen. 
GENERAL APPEARANCE AND NATURE OF ATTACK. 
Shade trees, shrubs, and hedges, and in particular evergreens, are 
much subject to injury by a medium-sized caterpillar which has a 
curious habit of crawling about on the infested trees in a bag-like case, 
whence its common name of bagworm or basket worm. 
In the shelter of these cases the insects undergo all 
their transformations, after which the bags remain 
attached to the plants for some time and are conspic- 
uous objects on leafless trees and shrubs in late autumn 
and in winter. Like the tussock moth” and the fall 
webworm?” this species 1s preeminently a pest on the 
streets and in parks and private grounds of cities and 
towns and is even more subject to fluctuation in num- 
bers. It is, however, more limited in distribution 
and not found asa rule north of southern New York 
and the central portions of Pennsylvania and Ohio. 
South of these points it is in certain years very trou- 
blesome and the subject of much complaint. Such a 
year was 1907, when the bagworm attracted greater et cae ally ves 
attention than any other tree defoliator. Numerous — ¢pnemerzformis). 
complaints were received of injuries in the region dabemc? (af- 
mentioned, and especially from the States of New 
Jersey, Pennsylvania, Maryland, Virginia, West Virginia, Ohio, 
Indiana, and Illinois. The natural enemies of this insect (see p. 6) 
were comparatively scarce, and there is a strong possibility of a recur- 
rence of injuries in the years to come. 
The general appearance of the bagworm is shown in figure 1, which 
illustrates the caterpillar when nearly full grown, in its ioe: 
bag. When removed from its bag it looks as hae in figure 2, a, 
which represents the larva et maturity. At this period in its oo 
« Hemerocampa leucostigma 8. & A. b eae cunea a 
20833—Cir. 97 
