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THE ENTOMOLOGIST. 
Insidens, Ratz.* 
Natzburg’s description of this species and its habits is quite 
unmistakable. Unfortunately Reinhard (‘ Berl. ent. Zeit.,’ 1881, 
p- 85) confused it with diffcilis, Nees, juniperate, Bouché, and 
other species, his synonymy being accepted by Marshall. After 
studying a very,large amount of material I am convinced that 
the species is quite distinct. I give below a description taken 
from forty-four specimens in my collection: 
Black ; palpi pale; belly at the base fusco-testaceous; legs rufo- 
testaceous ; fore and middle femora black except at apex, hind 
femora entirely black; hind tibie fuscous at apex, middle tibize also 
sometimes fuscous at apex. Wings rather dusky, stigma fuscous. 
Mesothorax punctulate, shining; scutellum smoother, also shining ; 
mesopluree smooth and shining; metathorax rugulose. Abdominal 
segments 1 and 2 rugulose, sometimes narrowly edged at the sides 
with testaceous, 1 longer than wide with subparallel sides, 2 
almost as long as 3, subcarinated and with two subobsolete con- 
verging lines ; other segments smooth and shining. (In this, as in 
other species, the second segment is longer in the male than in the 
female.) Hind coxee above punctulate, shining. Spurs of hind tibize 
stout, longer than half the metatarsus. Terebra very short. Length 
23-34 mm., expands 6-7 mm. 
The cocoons are yellowish buff, but soon turn almost white 
when exposed to light, and are attached to the host as described 
by Ratzeburg (fig. 1). When the host is a practically hairless 
caterpillar, the cocoons usually fall off, but with other hosts, 
such as Pacilocampa populi, they remain attached until the 
imagines have escaped. I have on more than one occasion taken 
a living but unhealthy larva of P. populi carrying on its back 
fifteen or sixteen empty cocoons of this parasite; and a larva 
of Asteroscopus sphinx, which was confined in a pill-box, was so 
lively at the time that its parasites emerged from their cocoons 
that when they settled on its body it showed every sign of expect- 
ing to be again ‘‘ stung,” throwing its head round and ‘ jump- 
ing” in the usual way. I did not, however, see any of the 
parasites attempt to oviposit. A curious thing occurred with 
regard to this particular larva of A. sphina, for although the 
parasite larvee evacuated the host on May 30th and 31st and the 
imagines emerged from their cocoons on June 8th and 9th, yet 
on June 10th I was surprised to notice a single parasite larva (1 
believe of an Apanteles) emerging from the unfortunate cater- 
pillar. This single parasite was evidently unhealthy, as it failed 
in its attempt to spin up, and both it and the host died on or 
about June 14th. I have obtained broods of this very common 
species from the following hosts: Phigalia pedaria, June 15th, 
1908, June 26th, 1910, and other dates; Amphidasys strataria, 
July 6th and 22nd, 1911, and many other times; Himera 
* ‘Ich. d. Forst,,’ i, p. 72, 
