THE FALL WEB-WORM. 53 
but in vain. Once a larva had just started to make a cocoon, but it 
was prevented from finishing it by a secondary parasite, and it died. 
Another larva had already 
spun the rough outside co- 
coon, but became detached 
and dropped out of the low- 
er orifice, and commenced a 
new one. The larva, sus- 
pended by the mandibles, 
evidently spins at first 
loose, irregular, horizontal 
loops around its body, until 
a loose cradle is formed. 
The silk secreted for this 
purpose hardens very rap- 
idly when exposed tothe air. 
When secure inside this b @ 
eradle it lets go its hold Fie. 24.—Meteorus hyphantrie: a, female; b, cocoon (en- 
with the mandibles, and he 
finishes the soft inside cocoon in the usual manner. If the larva has 
dropped to the ground it still makes an outer loose cocoon, but the 
silken threads are thicker and much more irregular. in cocoons made 
during a high wind the threads that suspend them are much longer, 
reaching sometimes the length of 4 inches; the more normal length 
varies from 14 to 2 inches. 
‘To find out the length of time which this insect occupies in matur- 
ing inside the cocoon, 44 freshly-made cocoons were put in a glass 
jar. With a remarkable regularity but ten days were consumed by the 
insect in changing from the larval to the winged form. The winged 
Meteorus issues through a perfectly round hole at the lower end of the 
cocoon by gnawing off and detaching a snugly-fitting cap. There are 
several secondary parasites of the Meteorus which we may mention later, 
and they always leave the cocoon of their host by smaller holes eut 
through the sides. Most of the adults had issued by the first of Novem- 
ber, butit is possible that some may remain in their cocoons until spring. 
‘In order to obtain the proportion between the J/eteorus raised from 
cocoons and its parasites, ?. e., secondary parasites of Hyphantria, 450 
cocoons were confined in a giass jar the latter part of September. Up: 
to the first week in November only 70 specimens of J/eteorus were bred 
from these cocoons, the rest giving out secondary parasites, which con- 
tinued to issue up to date of writing (December 20, 1886). Thus, only 
16 per cent, of the cocoons produced the primary, while 84 per cent. 
produced secondary parasites.” 
Apanteles hyphantrie Riley (Vig. 25 represents a closely allied spe- 
cies).—“ This insect was about as numerous as the Perilitus communis, 
