ELM CATERPILLARS. 



265 



In fact, the American Yellow-billed Cuckoo, the Baltimore Oriole, and the Robin are 

 the only birds which have been observed to feed upon the larvjs. Predaceous insects 

 are also not particularly fond of this hairy caterpillar, the well-known Wheel-bug 

 (Pnonidus cristatua, Fig. 104 ) and a few other Soldier-bugs being the only species 

 which occasionally suck its juices. Nocturual birds, and especially bats, will, no 

 doubt, devour many of the male moths flying about after dusk, but the destruction 



Fig. 104. — Prionidua cristatus: eggs, larvae, and full-grown specimens. (After Glover). 



of a portion of the males has no appreciable influence on the decrease of the worms 

 of the next generation. The egg-masses appear to be effectually protected by the 

 froth-like covering, as neither bird nor predaceous insect has beeij 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 influence that the caterpillars are 

 not permanently injurious. There are several true parasites of this insect. Fitch 

 described one species which he bred in considerable numbers from the larva, as 

 Trichogramma? orgyiw, but a perusal of his account indicates plainly that this par- 

 asite is an Eulophtis. He also described a closely-related insect as Trichogrammaf 

 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 geuus 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 parasitic upon one of the Pteromali. 



35. Halesidota tessellaria Hb. 



This beautiful insect, whether we consider the caterpillar or the moth, 

 is said by Harris to be very common throughout the United States on 



