for a fresh supply of food, should tempt it to cross this 
dus path. First one ant more vigilant than the rest would 
> the attack; then another, and another, until the poor cater- 
entirely covered by its pigmy foes, and completely exhaust- 
strength by its unavailable efforts to escape, was finally 
to succumb to superior numbers and die as quietly as pos- 
vken the carcass was immediately carried off by the captors 
"r nests, or, when too heavy to be dragged away at once, they 
m it as it lay in the road. This warfare was carried on 
lay as long as the grass worms prevailed, and no doubt their 
rs were diminished in this way to a considerable extent.” 
liley the occurrence of considerable numbers of a Tachina 
e was noted in 1870; and we, ourselves, noticed the eggs of 
parasite this fall on at least fifty per cent, of the worms col- 
by us, most commonly fastened near the head. The imago of 
these parasites emerged in a breeding cage on the ‘28th Novem- 
d believing it new, I sent it to Dr. Williston, of New Haven, 
ticut, who, at my request, kindly furnished me the following 
tion: 
Exorista infesta, sp. n., Williston. 
laic. Palpi reddish yellow at the tip ; third joint of the antennae 
bhrice as long as the second; a single row of bristles extends 
le front a little ways on the sides of the face above; the bristles 
face below do not reach the middle; legs black; scutellum 
sh, the tip of the abdomen reddish yellow. Length 6-7 mm. 
.£. Face grayish w T hite; on each side of the lower part of the 
front there are but three or four minute bristles above the 
larginal bristle. Antennae black, the third joint about three 
ts long as the second, of nearly equal width, straight on its 
largin. Front light ochraceous on the sides, in the middle 
rather broad, parallel, opaque black stripe, reaching from 
41i to the base of the antennae; on the lower part there is a 
row of not very stout bristles on each side, extending but a 
ays on the face. Palpi black, the distal end reddish yellow. 
light grayish pollinose, the dorsum showing four rather 
, black stripes, indistinct behind. Scutellum obscure yellow, 
dsh yellow, narrowly black at the base. Tegulae yellowish 
Abdomen black, the second and third segments very indis- 
r reddish on the sides, the fifth segment almost wholly red- 
llow; second segment opaque; third and fourth shining, 
r whitish pollinose in front, but variable in different reflections, 
vholly black. Wings hyaline; last section of fourth vein 
/tely curved inwards, posterior cross vein gently sinuous. 
. Front narrow above, the median black stripe narrower than 
emale, and gently widened in front. Palpi black at the base, 
es of the third and fourth abdominal segment broadly reddish, 
ise as in the female. 
3 specimens: one female (No. 5422), bred by Professor I orbes 
japhygma frugiperda, and a male and a female, collected by 
[gene Keen in Fairmont Park, Philadelphia. The females 
