88 
and without bristles; occiput bright ferruginous; labium ferruginous 
with hairs of same color; maxipalps rufous; eyes, dark mahogany 
brown, * and perfectly smooth; antennae, two basal joints rufous, with 
black hairs, third joint flattened, dusky, and thrice as long as 
second; seta black; entire hinder part of the head covered with 
dense white hairs. Thorax more decidedly blue than in leucanice , 
broader (instead of narrower) in front than behind; the vittae less 
distinct; scutel of same color as thorax. Abdomen stout and more 
cylindrical than in leucanice; first joint dark bluish-gray, becoming 
darker along the middle, at sides and at lower border; third joint 
like second above, but golden gray at sides (not rufous); last joint 
entirely yellow or pale orange, with no other color but a few black 
bristles around anus. Wings more dusky than in leucanice; alulae, 
opaque bluish-white. Legs, black; pulvilli pale yellow. Space be¬ 
tween eyes at occiput fully one-third the width of head.” 
It is possible that other allied species may be found attacking the 
Army-worm, but so far I believe these two are the only ones dis¬ 
covered. 
Microgaster militans. Walsh. 
Fig. 5.—Micro¬ 
gaster mili- 
taris. 
This little species, not exceeding the tenth of an inch 
in length, is a four-winged liymenopterous species, the 
form of which is shown in Fig. 5. It is black, with 
clear wings and rufous or reddish legs. The larvae of 
this little species often infest the caterpillars in large 
numbers, several residing in the body of one worm. The 
worms infested by this species show their parasitized 
condition by ceasing to eat, remaining sedentary, slug¬ 
gish and apparently paralyzed, in one place. They become too feeble 
and too much diseased even to enter the ground to pupate. At this 
stage, when the worm would be ready to go under ground if it were 
able, the little parasites issue from the body, boring their way 
through the sides, and spin a mass of cottony silk, in which each 
forms a little cocoon, closely resembling an insect egg; in fact, the 
mass is most generally taken, by the unscientific observer, to be 
a bunch of insect eggs. 
The following is the original description: 
“Length of body, .07-inch, or two millimetres; head, black; palpi, 
whitish; antennae, fuscous above, light brown beneath, towards the 
base; thorax black, polished, with very minute punctures. Wings, 
hyaline; nervures and stigma, fuscous; lower nervure of marginal, 
and exterior nervure of second submarginal cellule, entirely obso¬ 
lete. Lower nervure of third or terminal submarginal cellule, hya¬ 
line ; legs, light rufous, posterior pair with knees and tips of tibiae 
fuscous; abdomen, black, glabrous, highly polished; ovipositor, not 
exserted.” 
Lest this busy and brave little parasite should multiply so rapidly 
as to exterminate the “Army-worm and other vegetable-eating cat¬ 
erpillars, and thus disturb the counter-balance between animal and 
vegetable life,” Nature has furnished a check upon this increase in 
the shape of two still more minute liymenopterous parasitic species 
belonging to the Chalcid family. These are described by Mr. Walsh 
as follows: 
