34 OUR SHADE TREES AND THEIR INSECT DEFOLIATORS. 
juices. Nocturnal birds, and especially bats, will, no doubt, devour 
many of the male moths flying about after dusk, but the destruction of 
a portion of the males has no appreciable influence on the decrease of 
Fig. 16.—Prionidus cristatus: eggs, larve, and full-grown specimens. 
the worms of the next generation. The egg-masses appear to be eftect- 
ually protected by the froth-like covering, as neither bird nor predaceous 
insect has been observed to destroy them. 
While the list of enemies that devour the species is thus small, that 
of the parasites is fortunately quite large, and it is due to their influ- 
ence that the caterpillars are not permanently injurious. There are sev- 
eral true parasites of this insect. Fitch described one species which 
he bred in considerable numbers from the larva, as Trichogramma? 
orgyic, but a perusal of his account indicates plainly that this parasite 
is an Hulophus. He also described a closely-related insect as Tricho- 
gramma? fraterna and gave it as a very probable parasite of Orgyia. 
There is, however, not the slightest’ evidence of such parasitism, and 
this insect must in future be excluded from the list of parasites of the 
Orgyia larvee. We have reared from this insect Pimpla inquisitor, and 
an undetermined Tachinid fly, and have had from the larva the cocoons 
of a Microgaster which has not been reared to the imago. We have 
also bred a true egg-parasite of the genus Telenomus, two distinet 
species of the genus Pteromalus from the larvie, and Mr. Lintner has 
sent us a specimen of a species of Tetrastichus which is probably para. 
sitic upon one of the Pteromali. Further characterization of these 
species we defer to another occasion. ; 
