10 PAEASITES AND INQUILINES. 



Andricus marginalis. 



— albopunctatus. 



— seminationis . 



— solitarius. 



— glandulce. 



— Clementinas. 

 Dryophanta agama. 



— disticha. 



The first five are certainly agamic, but at present 

 we have no definite information about the others. 

 Andricus amenti (a spring bisexual form) is sure to 

 have an autumn agamic form. The galled acorns I 

 have found seem to point to an unknown species. 



Parasites and Inquiline or Guest Flies. 



The insects which live at the expense of the galls, or 

 gall insects, are exceedingly numerous. They are of 

 three classes : — First, inquilines ; second, parasites ; 

 and thirdly, commensals. The inquilines are species 

 of Synergus, Ceroptres, or Sapholytus, all forms nearly 

 related to the true gall makers. They do not make 

 galls themselves, but deposit their eggs in galls 

 already formed ; live in the gall substance ; and, as a 

 rule, kill the larva of the maker. The parasites are 

 chiefly Chalcididse, small brilliant blue or green 

 metallic Hymenoptera, which devour the larvse and 

 pupae of the gall or inquiline flies. The most con- 

 spicuous of these parasitic genera are Gallimome and 

 Torymus, which have a more or less elongated ovipositor 

 to enable them the better to penetrate into the galls, 

 the ovipositor with some of them being three times 

 longer than the body ; Eupelmus, Orymus, Megastigmus, 

 Eurytoma. These Chalcididee may confine their 

 attacks to one gall or to many, e. g. Eupelmus annu- 

 lata, E. Degeeri, Eurytoma vagabunda, and species of 

 Olinx. So far as my observations go these are all ex- 

 ternal feeders, and feed on the pupa as well as on the 



