56 



RESULTS FROM GIPSY MOTH PARASITE LABORATORY. 



in hyalinus and the ends of the chitinous bands which surround the 

 ])ody are simple, not terminating in long teeth or serrate as in the 

 other species. The dorsal and ventral bristles, however, are sti-onger 

 and more numerous, and somewhat differently arranged. 



Considerable difference in habit in these two species has also been 

 noted. P. liyalinus, we have reared from many different hosts, but 

 the other species has been foimd only upon the larva of Limnerium 

 validum. Instead of remaining internal within the Limnerium larva 

 until it attempts to pupate in the spring as does P. hyalinus, this 



species, if it ever feeds 

 end o parasitic ally, 

 must emerge from its 

 host soon after the co- 

 coon is spun, for it is 

 found externally upon 

 its host during the fall 

 and winter before the 

 Limnerium has any 

 intention of pupating, 

 and has never been 

 found internally. In 

 only one instance have 

 we succeeded in get- 

 ting this species to 

 feed, and even that did 

 not terminate satis- 

 factorily. During the 

 spring of 1909 a speci- 

 men of the planidium 

 of this species was 

 placed on a larva of 

 Limnerium in a glass 

 cell for observation. 

 Six days later the 

 planidium had not fed 

 and was noted as be- 

 ing apparently dead, but on the next day it was seen to have been 

 feeding, although its host was still alive and active. Five days later 

 the planidium had molted its skin and had taken on the globular form 

 of the second-stage larva but was apparently not in very good condi- 

 tion and died two or three days later. At no other time were we 

 able to get this species to feed. There is a possibility that it is of 

 purely accidental occurrence upon LAmnerium, and this may account 

 for our inability to rear the adults. This belief is strengthened by the 

 fact that a large percentage of the sjDecimens of this planidium are 



Fig. 30.—Perilampvs, "species Fig. Sl.—Pcrilampus, "species 



A:" Planidium, ventral view. A:" Planidium, dorsal view. 



Magnified about 400 diameters. Magnified about 400 diameters. 



(Original.) (Original.) 



