119 
Not only did I find them feeding upon the worms, but also inside the 
silken web destroying the chrysalids. Seizing one by the mandibles 
it would extract the contents, leaving the hard outer covering. This 
beetle has proved a great assistance in destroying the army-worm, 
Leucania unipuncta, Haw, the great caterpillar, Clisiocampa Americana , 
Harris, and the Canker-worm, Anisopteryx vernata, Peck. 
To the trim Lady-bird Coccinella munda, Say, we are indebted for 
assistance in checking the ravages of this oak-pest. 
They were found in considerable numbeis upon the 
infested trees. 
Two species of Hemipterous bugs, kindly deter¬ 
mined for me by Mr. P. R. Uhler, Baltimore, Md., 
were conspicuous because of the number upon the 
attacked trees. These are the Diplodus luridus, Stal, 
and a Podisus, probably Podisus spinosus, Dallas. 
C. Calidum. 
Parasite on Oak Leaf-Roller— Pimpla (Cryptus) conquisitor —Say. 
Perhaps the most efficient assistance comes through the medium of 
this parasite, since when attacked it is impossible to recover, and the 
insect must become a victim to the enemy. The female ichneumon 
deposits a single egg upon the worm, and the young larva enters the 
body as soon as hatched and commences feeding upon the fatty sub¬ 
stance of her victims, avoiding, however, the vital organs, since, should 
this occur, the caterpillar from wffiich she derives her subsistence 
would perish and her own life would thus be lost. When the worm 
is full grown it changes to chrysalis, and the parasitic guest does the 
same inside the chrysalis of the OakTortrix, destroying the life of her 
victim in so doing. Thus, instead of the moth issuing from the 
chrysalis made by the caterpillar, a full grown conquisitor (Fig. 27,) 
comes forth having gained its life at the expense of another. 
The presence of the parasite was easily 
determined by a darkened spot on the dorsal 
side of the caterpillar,and this was also observ¬ 
able in the chrysalis, and so far as I was able 
to ascertain the various insects which prey 
upon them made exception of those in which 
the parasite'had entered. 
To* Mr. E. T. Cresson, I am indebted for the 
determination of this species. 
p. conquisitor. For the benefit of those not acquainted 
with the insect, I append the following description : 
“Black, tergum with the posterior margins of the segments white; 
feet horny yellow, posterior tibiae and tarsi with black joints.” 
Body black, punctured; palpi, white; thorax, punctures minute; 
metathorax not distinctly punctured on the disk ; wings very slightly 
