294 
Journal of Agricultural Research 
Vol. XXIX, No. 6 
wing. The head and the thorax are 
bronzy to brassy green. The clypeal 
region, the under side of the thorax, 
and the propodeum are tinged with 
blue. The antenna (fig. 2, b) is black, 
except the scape which is testaceous 
with a fuscous apex. The legs are a 
reddish testaceous, except the coxae, 
which are concolorous with the thorax, 
and the apical tarsal joints, which are 
dark brown. The abdomen is black 
with bronzy metallic reflections. 
The male is somewhat smaller than 
the female and quite different in 
habitus. The head and thorax are 
bright metallic blue-green. The an¬ 
tenna (fig. 2, c) is fuscous, except the 
scape, which is very pale testaceous. 
The legs, including all of the coxae, 
are pale testaceous, except the middle 
tibiae (fig. 2, d)> which are black with 
narrow, pale testaceous bands at the 
base, and the apical tarsal joints, which 
are black. The fuscous spot is absent 
in the forewing of the male (fig. 2, e) 
but this sex of Polyscelis modestus may 
be distinguished from the other male 
Hessian fly parasites by the coloring 
of the legs. 
LONGEVITY 
The life of the adult female parasites 
was from 7 to 39 days in length, the 
average length of life for five females 
being about 24 days. The life of the 
male was considerably shorter than 
that of the female. It was from 5 to 
11 days in length, the average for 
four males being about 9 days, or 
less than one-half of that of the aver¬ 
age female. (See Table II.) 
SEX RATIO 
Thirteen adults of this species have 
been reared from Hessian fly puparia 
collected in the field. Of these 13 speci¬ 
mens 6 were males, 6 were females, 
and the sex of the remaining 1 was un¬ 
recorded, thus indicating a sex ratio of 
approximately 50-50. 
PARTHENOGENESIS 
Experimental rearings have shown 
that it is possible for this species to re¬ 
produce parthenogenetically. In two 
cases in which unfertilized females were 
provided with unparasitized Hessian- 
flv puparia for oviposition, progeny re¬ 
sulted which were of the male sex. 
OVIPOSITION 
According to observations recorded 
during these laboratory experiments, 
the first oviposition occurred from 5 to 
7 days after the emergence of the 
adults. It is very probable, however, 
that under natural conditions oviposi¬ 
tion begins somewhat earlier. 
It is also presumed that under natu¬ 
ral conditions not more than one egg is 
deposited within a puparium by the 
same individual parasite; but in the 
course of these experiments it was not 
uncommon to find two or three eggs 
or more than one parasitic larva within 
the same puparium when dissected. 
This is undoubtedly an abnormal habit 
which the parasite is compelled to as¬ 
sume on account of close confinement 
and the limited number of puparia 
Table II .—Longevity of the adults of Polyscelis modestus 
Emerged 
Died 
Longevity 
FEMALES 
May 8 . __ __ _ __ __ 
May 15 
Aug. 6 
Sept. 16 
Sept. 16 
Sept. 21 
Days 
1 
26 
39 
39 
8 
July 11 . . _ 
Aug. 8 . - - -- __ _ 
Aug. 8_ . . ____ ________ 
Sept. 13_ 
Average _ __ _ __- -_- 
23.8 
May 7.. 
Aug. 1.. 
Sept. 10 
Sept. 5. 
May 15 8 
Aug. 6 5 
Sept. 21 11 
Sept. 16 11 
A verage 
8. 75 
MALES 
