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 crista tus : eggs, larvae, and fall-grown specimens. 



the worms of the next generation. The egg-masses appear to be effect- 

 ually protected by the froth-like covering, as neither bird nor predaceous 

 insect has been observed to destroy them. 



AYhile 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 Trichogrammaf 

 orgyice, but a perusal of his account indicates plainly that this parasite 

 is an JEulojphus. He also described a closely-related insect as Tricho- 

 grammaf 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 larvae. 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 distinct 

 species of the genus Pteromalus from the larvae, 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. 



