66 RESULTS FROM GIPSY MOTH PARASITE LABORATORY. 



characteristics it resembles the planidium of P. liyalinus and others 

 described in the preceding pages. It is also probable that the later 

 larval development is analogous to that of P. liyalinus and that the 

 beginning of development of the pupa is the signal which stirs the 

 planidium into activity. 



Varicliseta, as has been shown, hibernates as a pupa which has 

 not begun to show the color or characteristics of the adult, and 

 the Perilampus planidium remains dormant throughout the winter 

 and feeds in the spring. Among the European tachinids known to 

 act the part of host to P. cui^rinus, Compsilura, Tricholyga, and Pales 

 issue in the summer, much as do the summer-issuing hymenopterous 

 parasites of the fall webworm, and P. cuprinus completes its trans- 

 formations and hibernates as an adult without leaving the pupariuni. 

 Blepliaripa, unlike Varichseta, develops imaginal characters in the 

 fall and is, so far as external evidences indicate, ready to emerge 

 before winter. Perilampus as a parasite of Blepliaripa acts exactly 

 as it would had its host actually emerged in the fall, and hibernates 

 as an adult within the puparium. Parexorista hibernates like Vari- 

 chse,ta, and if the parallel between P. liyalinus and P. cuprinus is as 

 close as is believed, the planidium hibernates as such and becomes 

 active when its host begins to develop in the spring. 



Perilampus inimicus Crawford. 



A relatively small number of this species, recently described in 

 Part II of this bulletin, was reared in 1908 from the cocoons of 

 Apanteles fulvipes var. japonica Ashm., imported that year from 

 Japan as a parasite of the gipsy moth. It has not been reared as 

 a parasite of Japanese tachinids, but it may well be that it resembles 

 P. cuprinus in habits, and that it will be reared when larger impor- 

 tations of tachinids from Japan have been made. 



The specimens reared issued in the late summer, coincidently 



with the emergence of the other more common chalcidoid parasites 



of the same host. 



Perilampus sp. 



Another species of Perilampus, as yet undetermined, has been 

 reared from the cocoons of a European Apanteles parasitic u])on 

 the young brown-tail moth caterpillars. The circumstances are 

 interesting and suggestive but the incident will be discussed more 

 at length in another connection. 



RESUME OF HOST RELATIONS OF THE GENUS. 



Species of the genus Perilampus have been reared ^ from insects 

 belonging to five different orders, Hymenoptera, Diptera, Lepi- 



J This is according to the published records, although some of them are almost certainly incorrect. 



