13 
spins on the tree, a delicate grayish cocoon of silken web mixed with 
its own long hairs. It changes to a pupa within a few hours after 
the cocoon is finished and continues in this condition from ten days 
to two weeks. , • , i-n: 
The adults are moths, the females (Fig. lo) of which ditter 
very widely from the males (Fig. ii) in the fact that they are 
almost absolutely wingless. The males have good wings and at 
Fig. 11. White-marked 
Tusbocli-motti, Hemero- 
cu'/npa leucostigma, male. 
Natural size. 
Fig. 10. W bite-marked Tussock- 
moth, Hemerocampa leucost-gma. 
female and egg masses Natural 
size. (Connecticut Kxpenment 
Station ) 
least the average power of flight. They are of an ashy gray color 
witl, dark wavy bands across the fore wnigs, a small black 
pot on the outer edge near the t,p, a blackish stnpe be- 
,'ond this, and a ntnrute white crescent near the h.nd ang 
The wings, wlicn expanded, measure about one and a fourth 
inches across. The fen,ale has little of the appearance of a 
n,oth, her wings being reduced to the merest '"dmren s. Her 
thick oblong-oval body is of a hght gray color with rather 
ong legs, and is distended with eggs. When she comes out 
shefays hCT egg mass on the cocoon from wind, she emerged-a fact 
whicl makes i? plain that the species can spread on y by way of the 
wandering caterpillars, or bv the transportation of egg .masses on 
™i"ng les. The eggs of the last generation are orchnanly pro- 
ducecl in September cmd the winter is passed in this condition. 
Ma V insect parasites infest the pupa and do much towards hokl- 
inc the spec es in checl^. They are not usually abundant enough, 
lowerei^'to control it completely In the fall o ^J^or example^ 
one of my assistants reported that 75 percent of the "'^"'^ °* 
die tussock-moth in the Chicago parks were parasitized, but t e 
"aterpillars were nevertheless .very numerous and destructive the 
