144 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



dance of this insect the past summer in Washington, D, C, provided 

 the longed-for opportunity. Mr. E. R. Sasscer, of the Bureau of Ento- 

 mology, kindly consented to send us caterpillars. About five hundred 

 second generation caterpillars arrived from him the latter part of 

 August. Beyond a few crushed in transit the}^ appeared healthy and 

 in good condition. Attached to some leaves which had served as 

 food were two first generation pupae which had failed to mature. 

 These were examined and found to be full of polyhedra. Two days 

 later a caterpillar was found dead, hanging by the prolegs. When 

 grasped by a pair of forceps, its prolegs were left clinging to the side 

 of the box. The case was as typical as any we had seen in the 

 gipsy moth and the polyhedra were just as plentiful. A few of these 

 caterpillars died each day until less than one dozen pupated out of more 

 than five hundred caterpillars. 



The Oak Caterpillar, Phryganidia californica 

 Early last spring we received word from one of Professor Kellogg's 

 students at Stanford saying, ^'The Oak caterpillars are dying with a 

 disease similar to wilt." We wrote him for material which he kindl}^ 

 sent; and though in poor condition when we received it, we were able 

 to confirm his observations. Polj^hedra were found in abundance in 

 the dead caterpillars. According to his description of the disease it 

 completely controls this pest at times and like wilt does the most good 

 when defoliation has almost taken place. 



The Range Caterpillar 



Mr. H. E. Smith of the division of Cereal and Forage investigation 

 has, the past summer, been working on the Tachinid parasites of the 

 range caterpillar at the Melrose Highlands Laboratory. 



On learning that we had found the wilt in other species of caterpillars 

 besides the gipsy moth, he sent us a few Range moth caterpillars, one 

 of which showed typical wilt symptoms. It proved on examination 

 to be a very typical case. Since this was the last of his stock we have 

 not had an opportunity to examine others, and therefore cannot say 

 whether the wilt occurs naturally in the field or not. We will have to 

 wait another season to determine this point. 



unable to find any pupae. Upon examination, the dead caterpillars were found 

 everywhere clinging to the branches, and also occurring in great abundance on the 

 ground beneath. Some few caterpillars were yet ahve, but were very sluggish. • I 

 collected some of these and carried them home, but they all died apparently from 

 wilt," etc. 



Mr. Houser enclosed some of the caterpillars he collected at that time. The 

 abundance of the polyhedra in these caterpillars shows that they died of wilt. 



