36 OUR SHADE TREES AND THEIR INSECT DEFOLIATORS. 
THE FALL WEB-WORM. 
(Hyphantria cunea, Drury.) 
“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 sufliciently 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 September, while in more southern regions it is double- 
brooded. In our Third Missouri Report we have first called atten- 
tion to its double-broodedness at Saint 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 wide- 
spread damage, while the fall brood nearly always attracts atten- 
tion. 
‘‘We have decided to call attention to this insect sontahann in detail 
in this report, because of its exceptional prevalence and injury in the 
Atlantic States during the year 1886, and because it became a public 
nuisance in the city of Washington, and the District Commissioners 
have formally requested information from us on the subject.” 
NATURAL HISTORY. 
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 Sep- 
tember. In Massachusects 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 seek- 
ing places for transformation from the end of August to the end of Sep- 
tember. 
‘‘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, 7. e., they will be found issuing and flying 
slowly about during the evening, and more particularly at night, dur- 
ing the whole month of May, the bulk of them early or late in the month, 
according as the season may be early or late. They couple and oviposit 
