BEARINGS AND DISSECTIONS OF TACHINIDiE. 105 



it is readily seen tliat this maggot is especially well adapted both to 

 remain a very considerable time in the air and to cling to and make 

 its way over the skin of the caterpillar as soon as the latter presents 

 itself. ' 



This species possesses the further peculiarity of transforming to its 

 last maggot stage inside the chitinized anal penultimate-stage skin, 

 and also of changing to the pupa within the same, the whole remain- 

 ing inclosed in the caterpillar skin. As a consequence the puparium 

 is very thin and light colored, since it is protected from the action of 

 both light and air by the caterpillar skin as well as by the penulti- 

 mate-stage maggot skin. 



ZYGOBOTHRIA NIDICOLA Townsend. 



Zygohothria nidicola ToAvns. is another species which has exactly 

 the same habit of last-stage maggot and puparium as that just de- 

 scribed for E. 7nag7iico7-'nis. It is an extremely interesting species in 

 many ways. The two sexes are so different in appearance that they 

 might be taken for distinct species or even genera. The males, in our 

 experiments, began issuing from the puparia much in advance of the 

 females. The species has been reared from Eiqjroctis clirysorr]i(xa 

 only, and then under such conditions as to indicate that the females 

 oviposit on the young caterpillars in the fall, the young maggots 

 hibernating in the chryso'n'haui nests with the young caterpillars. 

 For this reason it Avas named niflieola. Though the sexes are so 

 different, the fact that they belong together has been proved by their 

 issuance from puparia having the same anal stigmata. No oviposi- 

 tion .was secured, but by dissecting females the ovarian eggs were 

 found to be elongate, whitish, and much like the unhatched uterine 

 eggs of Eiipeletcria magnieorvis. 



ZYGOBOTHBIA GILVA Hartig- and CARCELIA GNAVA Meigen. 



Zygohothria gilva Hartig is a close relative of the preceding spe- 

 cies, but has been reared by us from Porthetria dispar only. Its egg, 

 which has been found b}^ 'dissecting the female, is quite similar to that 

 of Zygohothria nidicola. 



Of somewhat the same character is the e,gg of Carcelia gnava Meig., 

 which has been reared from both Etqyroctis chrysorrhoea and 

 Porthetria dis/xir. The deposited egg of gnava has been secured. 

 The fly places its eggs on the caterpillar. The Qgg is not as slender 

 as that of gilva. 



PARASETIGENA SEGREGATA Rondani. 



The last group of species with which we have to deal is charac- 

 terized by depositing, on the caterpillars, eggs more or less oval in 

 shape, of comparatively large size, with one exception whitish in color. 



