25(1 THE CANADIAN ENTOMOLOGIST. 



imagoes do not live long; I never could keep them in captivity more than 

 three days, but when kept in the cold I have had them over a week, and 

 when brought into the warmth they were perfect and active ; when kept in 

 a large glass jar they paired readily, and the females oviposited in 

 the terminal buds of living willow twigs. I tried them with different 

 kinds of food, sugar, starch, glucose, cherry-tree gum and water, but 

 I could not get them to eat. I do not think that during their brief 

 imago life they either eat or drink. 



There are four species of inquilines more or less common in this gall, 

 the most noteworthy being the minute and beautiful C. albovitta, Walsh. 



1 found mature larvae of this inquiline resting in the downy folds of 

 the aborted leaves, well within the gall. Tney are cylindrical in shape, 

 slightly flattened ventrally, of a pale orange colour, and about i y 2 mm. 

 long ; I could find no evidence of feeding. The date of emergence 

 ranged from April 14 to June 23; this extreme range may have been 

 from artificial conditions, although I tried to secure natural conditions as 

 much as possible. I found them quite numerous ; one season I had 200 

 specimens from 54 galls; another season, 1892, I had 163 specimens from 

 35 galls. 



The common sawfly inquiline emerged sparingly, every season about 



2 to 100 galls. A smill beetle and a small plume moth similar to the 

 species that is inquiline in galls of R. triticoides, emerged rarely. 



Among the hymenopterous parasites was the ichneumon, Pimpla 

 annulipes. It was not common, and there was a suspicion that it was 

 parasitic on the sawfly larvae. 



. Two species of Torymus, one with an especially long ovipositor, both 

 resplendent in metallic green and blue colors, emerged about the middle 

 of June. 



Two species of small Chalcid parasites emerged a little later than the 

 Torymus, and it was thought that at least one of them was a secondary. 



The geographical range of this gall is ample ; it extends far to the 

 south, and is common over Ontario. I have found it in Algonquin Park 

 and in the Temagami District, and have galls from Southern and North- 

 ern Manitoba, from Alberta and from North Saskatchewan. 



There are many complicated and interesting problems awaiting the 

 student of Entomology, in working out the life-histories and interrelations 



