June 15, 1921 
Life-History Studies of Three Jointworm Parasites 425 
This species proved to be much more tractable than either of the other 
two treated in this paper. They bred freely in the cell slides through 
five generations during the breeding season of 1918. The larvae are 
very active and are voracious feeders. Never more than one individual 
was found to develop upon a single host lqrva, though as many as 8 
eggs have been found in a single jointworm cell that was taken from a 
breeding cage. Under field conditions, however, this would scarcely 
obtain, since the jointworm cells so far outnumber the adults of Eupelmus 
allynii which are present. 
PREPUPA 
The prepupal stage (PI. 78, G; 77, G) for 17 individuals of this species 
ran from 1 to 3 days, the average being 1.7 days. Upon entering this 
stage the larva voids considerable excrement, the prepupa being then 
pure white in color. At no other time has the larva ever been observed 
to void excrement. Upon entering this stage the larva contracts both 
in length and width. The third thoracic and first, second, and third 
abdominal segments become much shorter. There are numerous lateral 
fleshy folds at this time. The setae are arranged the same as are those 
of the full-grown larva. 
PUPA 
When the pupa (PI. 77, H) is first formed it is pure white. It gradually 
changes to intense black. Larvae of this species that became full-grown 
in glass cells late in the fall usually did not pupate until the following 
spring, although a few remained in the pupal stage through the winter 
when kept in a cold cellar. Sixty-two individuals remained in the pupal 
stage from 7 to 33 days during the breeding season, depending upon 
weather conditions. The average length of the pupal period was 21 
days. The pupa of the male is smaller than that of the female; the aver¬ 
age length of 5 male pupae was 2.142 mm. and the greatest width was 
0.658 mm. The average length of 4 female pupae was 3.0275 mm., and 
width 0.7875 mm. 
aduut 
This species (fig. 13; 14; 15, a, b) overwinters as full-grown larva in 
the jointworm cells in old wheat stubble, the first adults emerging the 
latter part of April or the first week in May, in Virginia. Males normally 
occur, though under cage conditions this species will reproduce partheno- 
genetically, unfertilized females producing male progeny only. 
The adults of this species are very active, and soon after emergence 
the females run rapidly up and down the old wheat stubbles nervously 
stroking the stubble with their antenna in a diligent search for a 
suitable place to oviposit. They fly very quickly and rapidly but 
apparently only a few feet at a time. The manner of oviposition is 
