8o Observations on Cynipidae. 



When they have acquired by degrees a dark brown 

 colour, we may consider that larval growth within them 

 is complete, but the galls must still be left the whole 

 winter in the open air. The larva then passes the 

 following year as such, and in October assumes 

 the pupa state. The flies appear in December and 

 January, but there is always a fair proportion of galls 

 from which insects do not emerge until the third year. 



Fly. Size 1-5 mm. ; wingless; the whole fly brownish 

 red ; legs light yellowish brown ; thorax dull and 

 punctured ; scutellum hairy ; abdomen almost sessile 

 and very shining, vertex finely shagreenedj in the 

 middle line a shallow furrow with a little protuberance 

 on each side. Antennae of thirteen joints, labial 

 palpi of two joints, maxillary palpi of four joints. 



Experimental breeding. I could not at first discover 

 where this species laid its eggs. It was very certain 

 that the insect which emerges in January could not 

 be the author of the galls of Biorhiza renimi formed 

 on the leaves in September. A consideration of the 

 structure of the ovipositor would lead one to imagine 

 that the insect punctures buds, but I could not at first 

 succeed in seeing the fly lay its eggs. In December, 

 1878, I reared a certain number of flies which I placed 

 upon a little oak. At first they remained perfectly still, 

 then they began to move about, and feel the adventitious 

 buds on the stem with their antennae. At last they 

 pierced a few of the buds, and at the end of April in the 

 following year a little red gall, which I soon recognized 

 as that of Trigonaspis crustalis, grew from two of 

 these buds. 



