268 ENTOMOLOGICAL SOCIETY 



conclusions in the main were probably correct, he hesitated to 

 condemn Walsh without the most careful consideration of all 

 the circumstances. Where a full-fed saw-fly larva enters the gall 

 of another insect, the entrance-hole must be perfectly visible, and 

 it seems incredible that Walsh could have overlooked this en 

 trance-hole. It is possible that the galls were collected in large 

 numbers and that the saw-flies issued from the mass of galls, so 

 that there was hardly an opportunity for investigating this point. 

 He further said that the saw-fly might oviposit in the epidermis 

 of a young Cecidomyiid gall quite as well as in the epidermis of 

 a twig or leaf, and that the saw-fly larva might develop with the 

 Cecidomyiid gall. He further said that the leaf-galls of Nemati- 

 das fall to the ground with the leaves in autumn and that the full- 

 grown larvag issuing from them would not be apt to reascend the 

 plant and bore into the galls. 



Mr. Marlatt, in reply, said that in the species which he had had 

 an opportunity to study, and in the available records of the rear- 

 ings, the parent saw-flies issued too early in the spring to oviposit in 

 the epidermis of Cecidomyiid or other galls. The Euuras emerge 

 long before the time of leafing in spring, in late February or 

 early in March, and the Nematids, producing galls on the leaves, 

 issue in the latter part of March or early in April, with the first 

 appearance of the leaves. He also said that the larvae coming 

 from both the stem-galls of Euura and the leaf-galls of Nematus 

 abandon their galls early in the autumn, before the leaves fall 

 and in fact while they are still green. He said, also, that many of 

 these inquilines were reared from leafy galls, in which no 

 entrance-hole would be necessary. 



Dr. Riley, replying, said that while it is true that saw-flies gener 

 ally issue early in the season, they come out very irregularly, and 

 some are much later than others, and he saw nothing impracti 

 cable in the idea that oviposition might take place exceptionally 

 on Cecidomyiid galls. Mr. Schwarz said that many saw-fly larvag 

 construct hibernating burrows in the dry bark of trees, and suggested 

 that these burrows should be collected and studied, since they are 

 characteristic with each species, in this way being somewhat 

 analogous to Scolytid burrows. Other saw-fly larvae bore in the 

 hard wood, and he remembers having found the larvae, probably 



