302 



PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 



Fig. 71. — Pales pavida: Second-stage larva in situ in 

 basal portion of integumental "funnel." Much en- 

 larged. (Original.) 



Not very much that is definite can be said of the seasonal history 

 of Pales. It undoubtedly will require another host than the cater- 

 pillar of the brown-tail moth in 

 order that it may complete its 

 seasonal cycle, but that it will 

 find such a host is pretty cer- 

 tain. It would rather appear, 

 from what has been observed, 

 that it will attempt to hibernate 

 as an adult. Whether or not it 

 will be able successfully to do 

 this in New England remains to 

 be proved. 



It has occasionally been reared 

 as a parasite of the gipsy moth, 

 and if successfully introduced 

 into America it ought to be of 

 some assistance in this role also. 

 Unfortunately, as a parasite of 

 the caterpillar of the brown-tail 

 moth, it does not issue until 

 about the time when the moth 

 would have issued had the individual remained healthy. It requires 

 some little time for the females to develop their eggs, and it is not 

 at all likely that, like Compsilura, it will be found to pass one genera- 

 tion upon the caterpillars of the 

 brown-tail moth, and the next 

 upon the gipsy-moth caterpil- 

 lars. 



Zenillia libatrix Panz. 



This parasite, like Pales, de- 

 posits its eggs upon foliage to 

 be eaten by its host, but, unlike 

 Pales, it has not been reared 

 through its stages in the labo- 

 ratory. Like Pales, it is south- 

 ern in its distribution, and in 

 relative importance they are 

 abont equal, judging from the 

 numbers of each which have 

 been reared at the laborator}^. 



It was colonized in small 

 numbers in 1906, in larger numbers in 1907, and in very small num- 

 bers subsequently. The circumstances attending its colonization are 



Fig. 72.— Pales pavida: Integumental 

 ing orifice in skin of host caterpillar. 

 (Original.) 



funnel," show- 

 Much enlarged. 





