38G MAUD D. HAVILAND 



Tory mils prupinquis, previously alluded to, is now an 

 ectoparasitic of a, gall-forming Cecidomyiid of the nettle, but 

 if this view is correct, its ancestors inhabited this, or a similar 

 gall, as inquilines, and later acquired the habit of devouring 

 the maker of the growth that harboured them. 



The intra-specitic origin of ])arasitism in bees may find 

 ;i ]>a,rallel among inquilines, for it is quite conceivable that 

 certain individuals may have adopted the habit of ovipositing 

 in a ready-formed gall, and thus became inquilines to their 

 own species. Cameron (2) remarks that among the Cynipidae, 

 the known inquilines are species of Synergus, Ceroptres, 

 or S a p h o 1 y t u s , which are all forms nearly related to the 

 true gall-formers. 



The view that parasitism is deri\ed frum inquilinism would 

 account for the diversity of the hosts of the Parasitica. Galls, 

 and similar i)lant deformities, are caused by insects of other 

 groups, such as many Hemiptera, l)ii)tera, and Lepidoptera. 

 The ancestors of the Parasitica may have used these as well as 

 the galls produced by members of their own family, and later 

 become parasitic upon the insects which formed them. 



It will be very desirable in future to investigate fully the 

 l)ionomics of the forms reared from, for example, Cynipid 

 galls. If any, generally found to be inquiline, are proved on 

 occasion to devour the maker of the gall, it will support the 

 suggestion that the Parasitica are descended from inquiline 

 ancestors. 



Summary. 



1. Asaph es vulgaris, Wlk., Pachycrepis clavata, 

 ^\'lk., and Pachyneiiron, sp., are hyperparasites of apliides 

 through the larvae of certain Braconidae (Aphidius). 



2. Oviposition took place after mating for Asaphes and 

 Pachycrepis, and parthenogenetically for P a c h y n e u r o n. 



3. The eggs are deposited upon the body of the host when 

 the latter is fully fed and about to undergo metamorphosis 

 within the skin of the aphide. 



4. The larvae feed ectoparasitically upon the host, which 

 soon becomes a decomposing mass. 



