264 ENTOMOLOGICAL SOCIETY 



gained in the study of these galls and of the habits of the larvae, and 

 in the rearings, has resulted in some interesting facts, the signifi 

 cance and accuracy of which have been substantiated by examina 

 tion of the earlier breeding records contained in the Department 

 notes, and in the records attached to specimens in the collections 

 of the National Museum, the Entomological Society of Philadel 

 phia, and Cornell University, together with the published records, 

 particularly those of Walsh. 



Proper reference of galls. Examination of notes and rec 

 ords indicated at once that there had been considerable confusion 

 in the references of galls received at vaious times, the result being 

 that a great many Nematid (Pontania)* galls have been referred 

 to the genus Euura, and, where parasites have been reared, these 

 have in sofne instances been named euurce, from an entire mis 

 conception of the host.f 



Such errors of determination from the gall may be avoided if 

 it be remembered that the species of the genus Euura, so far as 

 we have any record, always produce galls on or in the twigs, one 

 form (JS. salicicola Sm.) developing in the pith without result 

 ing gall formation. The bud Euura {E. orbitalis Norton) is 

 only an apparent exception, as this gall is really formed in the 

 young twig represented by the undeveloped bud. On the other 

 hand, all the species of Pontania of which the habits are known 

 cause galls in or on some portion of the leaf. The habit of these 

 two genera in this respect is so constant that any of their galls 

 may be properly referred with scarcely the possibility of error. 



Hibernation of the larva. The idea has hitherto obtained 

 that the larvae of most gall-making Nematids normally winter in 

 the galls themselves, or that, abandoning the galls in the fall, 

 they enter the earth to hibernate, or more rarely hibernate in rub 

 bish on the surface of the ground. Hibernation within the galls 

 was supposed by Walsh to be generally true of pomum and des- 

 modioides, while pisum, he states, hibernates normally in the 

 earth. Of the Euuras a common habit, at least of ovum and 

 nodus, according to Walsh, is to hibernate in the galls. The ex 

 perience gained from the specimens referred to above has indi 

 cated that this idea of hibernation is not the correct one for most 

 species. The galls received from Mr. Horton, chiefly those of 

 Euura ovum and Nematus pisum, were, in every instance, 

 abandoned by the larvae in September, while the leaves were still 

 green and before cold weather had set in. In cages supplied 



* All the gall-making species of the old genus Nematus are now as 

 signed to Costa's genus Pontania. 



f Bassus euurce Ashm., reared from Pontania restnicola n. sp. 

 Pimpla euurce Ashm., reared from Pontania pyri/ormis n. sp 



