104 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
Our experience accords with that of Mr. Hubbard, though the number 
infesting a single egg is not invariably two. We have often obtained 
but one from a single egg, and, according to Mr. Schwarz's experience, 
three may exceptionally be obtained. As will have been gathered from 
Mr. Hubbard's notes quoted above, the Trichogramma has been raised 
from the eggs of Heliotliis armigera — the Boll- Worm moth. It has also 
been reared from the eggs of Lapliygma frugiperda, the Grass-Worm 
moth, and from the eggs of an unknown Tortricid on orange. We have 
also found a minute yellow parasite of somewhat similar general ap- 
pearance and easily mistaken for it, but in reality very distinct when 
carefully examined, infesting the larva and the pupa of an undescribed 
Aleurodes that is common on cotton, two or more flies issuing from each 
Aleurodes. 29 " 
Infesting and issuing from the Worm. — The Cotton-worm Microgaster.— 
This species, described by us as Apantcles aletice,* has been very fre- 
quently found during the past few seasons in Florida, Alabama, and 
Texas. 30 The egg is laid in the posterior portion of the body of partly- 
grown larvae of Aletia (never in very young or full-grown worms). It 
is a solitary parasite, only one specimen infesting a single Cotton Worm. 
We quote the observations upon the species made by Mr. Hubbard, 
who has watched it more carefully than any of the other agents : "Late 
in August, while the worms of the fifth brood were in process of devel- 
opment, I discovered on the underside of lower leaves of cotton and 
upon grass growing under the shade of the oak tree at the center of 
this brood, a number of little oval cocoons of white, flossy silk, about 4 mm 
(0.1G inch) long. Close beside these dangled the dead body of a young 
cotton worm, suspended from the leaf or from the cocoon by a thread 
of silk. In about a week each cocoon produced a Microgaster (most 
of my notes relating to this parasite having been lost, I am unable 
to give the exact periods in which it undergoes its transformations). 
Subsequently I observed the larva, naked and memberless, its body 
tinged with green by the juices of its prey, in the act of spinning its 
cocoon. The larva forms the exterior by throwing out loops of ropy 
fluid which, under a lens, are seen to become rigid as they fall, and to 
harden rapidly, forming rather a coarse strand of white silk, which is 
often beautifully furred. These loops are piled one upon another and 
the walls of the cocoon rise rapidly until they meet overhead. The in- 
side is lined in the manner usual with lepidopterous larva? until the 
whole has become opaque. The process of spinning occupies about two 
hours 7 time. After August 20, nearly all the young larvsB of Aletia col- 
lected were found to contain this parasite, which kills and emerges 
from the worms when they have attained a quarter of their full growth. 
In quitting its host the parasite maintains its connection with the body 
* Transactions of tho Academy of Science of St. Louis, Vol. 4, No. 2. 
