244 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 
30. TUB FALL WEB-WORM. 
Hyphantria vunea Drury. (//. textor Harris.) 
(Ravages. Plate XXXVI.) 
Passing the winter in the pupa .state The coeoons found during the winter prin- 
cipally at the surface of the ground, mixed with dirt and ruhhish, or in cracks and 
crevices of tree-hoxes, in fences, and under door-steps and basement walls. The first 
moths issue from these cocoons in May, and laying their eggs in flat batches on the 
under side of the leaves. The young worms feeding preferably in company, webbing 
first one and then several leaves together, and gradually extending their sphere of 
action until a large part of the tree becomes involved. The worms becoming full- 
grown in July, and spinning cocoons from which a second generation of moths issues 
early in August and lays eggs, from which the worms hatch, so they are once more in 
force by the latter part of August. The parent moth white, with a varying number 
of spots ; winged in both sexes; the female preferring to oviposit ou box-elder (Xe- 
gundo aceroides), the poplars, cotton woods, ashes, aud willows. 
The following account is copied from Professor Riley's " Our Shade 
Trees and their Insect Defoliators," as it contains the results of the 
latest investigations : 
This insect has from time to time attracted general attention by its great injury to 
both fruit and shade trees. Many authors have written about it, and consequently 
it has received quite a number of different names. The popular name " Fall Web- 
worm," first given to it by Harris, in his " Insects injurious to Vegetation," is suffi- 
ciently appropriate as indicating the season when the webs are most numerous. 
The term is, however, most expressive for the New England and other northern 
States, where the insect is single-brooded, appearing there during August and Sep- 
tember, while in more southern regions it is double-brooded. In our Third Missouri 
Report we have first called attention to its double-broodeduess at St. Louis, and 
we find that it is invariably two-brooded at Baltimore and Washington. Except in 
seasons of extreme increase, however, the first brood does no widespread damage, 
while the fall brood nearly always attracts attention. 
Limitation of broods. — At Washington we may say in general that the first brood 
appears soon after the leaves have fully developed, and numerous webs can be found 
about the first of June, while the second brood appears from the middle of July on 
through August and September. In Massachusetts and other northern States the first 
moths issue in June and July ; the caterpillars hatch from the last of June until the 
middle of August, reach full growth and wander about seeking places for transforma- 
tion from the end of August to the end of September. 
The species invariably hibernates in the chrysalis state within its cocoon, and the 
issuing of the first brood of moths is, as a consequence, tolerably regular as to time, 
i. e., they will be found issuing and flying slowly about during the evening, and 
more particularly at night, during the whole month of May, the bulk of them early 
or late iu the month, according as the season may be early or late. They couple and 
oviposit very soon after issuing, and in ordinary seasons we may safely count on the 
bulk of the eggs being laid by the end of May. During the month of June the moths 
become scarcer and the bulk of them have perished by the middle of that month, 
while the webs of the caterpillars become more and more conspicuous. The second 
brood of moths begins to appear in July, and its occurrence extends over a longer 
period than is the case with the first or spring brood. The second brood of cater- 
pillars may be found from the end of July to the end of September, hatching most 
extensively, however, about the first of August. 
In Massachusetts and other northern States the first moths issue in June and July ; 
the caterpillars hatch from the last of June until the middle of August, reach full 
