208 PARASITES OF GIPSY AND BEOWN-TAIL MOTHS. 



Occasionally, however, a few secondary parasites have been reared 

 from puparia from abroad either because these puparia were col- 

 lected in part in the open or because the parasites were of species 

 which attacked the primary parasite during the life of the primary 

 host. The number of secondary parasites having such habit is 

 apparently very limited, and it has been definitely proved of but two 

 genera, namely, Perilampus among the chalcidids and Mesochorus 

 among the ichneumonids. The latter has never been reared as a 

 parasite of any tachinid. 



Because of the rather extraordinary precautions which were taken 

 to avoid introducing into America the secondary, together with the 

 primary, parasites of the gipsy moth and the brown-tail moth, the 

 whole question of secondary parasitism is worthy of considerable 

 attention in anything which purports to be a history, however 

 abbreviated, of the operations conducted at the parasite laboratory. 

 In the case of those attacking the tachinids it is better that they be 

 briefly considered en masse, since there are very few among them 

 with host relations restricted other than physically. 



Perilampus cuprinus Forst. 



Actually, only a very little is known of this species from first-hand 

 investigations further than that it is occasionally reared from puparia 

 of any species of tachinid parasitic upon the brown-tail moth or gipsy 

 moth in Europe, and under circumstamces which strongly indicate 

 a habit of making its attack before the death of the primary host. 

 At the same time it is felt that much is known of the probable habits 

 of this species through analogy as the results of Mr. Smith's studies 

 of the early history of the allied American species, Perilampus 

 Jiyalinus Say, which attacks the parasites, both hymenopterous and 

 dipterous, of the fall webworm. Presumably, like the American 

 species, its minute first-stage larva, or "planidium," gains access to 

 the host in some manner not quite clear, and after wandering about 

 in its body for a time enters the bodies of such parasites as it chances 

 to encounter. 



That a secondary parasite having such habits might be expected 

 to be peculiarly a parasite of the parasites of one particular host 

 rather than of the same or similar parasites of another host, coupled 

 with the fact that extraordinary precautions were obviously necessary 

 to provide against its accidental importation, made Perilampus 

 cuprinus appear peculiarly abhorrent, and for a time following the 

 discovery of the early habits of P. Jiyalinus precautions against the 

 importation of its congener were redoubled. In the course of time it 

 was determined that it was never present in sufficient abundance 

 to make it at all probable that it was a parasite of the gipsy moth or 

 the brown-tail moth parasites to anything like the extent to which 



