215 
April, ’89.] history society of Wisconsin. 
individual plant or even in the same cluster with the galls 
of Cecidomvia. The former species also probably produces 
its next brood of galls oil some other plant. The large 
white larva, which seems not to be infested by Hymen op- 
terous parasites pupates some days later than the Ceci¬ 
domvia larva, and the imago also appears later, from 
about the 17th to the 20th of May. The dark-colored fly 
emerges at the apex of the gall after dt agging out its 
pupa case, which is left dangling among the woolly hairs 
on the outer surface of the leaves. The insect hops and flits 
about in a much more lively manner than the Cecidomy ia. 
The males and females differ considerably in appearance, 
as will have been gleaned from the above description. 
Their actions are as different as their appearance. The fe¬ 
male carries her wings horizontally and overlapping on 
the abdomen after the manner of the Hemiptera. The 
long yellow oviposter is often carried protruding. The 
males are at once recognized by their smaller size, greater 
grace of form and movement, and by the peculiar manner 
in which they carry their wings. Tliese are held out at ri 0 it 
angles to the long axis of the body and allowed to dioop 
somewhat. From what I have observed I am incline to 
believe that copulation is preceded by a kind of coui ts ip in 
every way comparable to what is observ ed in higher a 
mals. The males ran about over the leaves in teja 
which they were confined in pursuit of the females. e A . 
dom used their wings but seemed to rely foi progre 
almost exclusively on their long and delicate legs. \ f 
°ne approached a female, she rose into the air an a i 0 
some distance off. I have repeatedly" obsei \ed t ns c ° c l 
fish action which had every appearance of being a e 
fhe ardor and agility” of the male, as with higher an 
Further studies of the habits of such of out msec s a 
Present striking sexual differences will undoubte y 
many cases of courtship, no less wonderful than t 
served in birds. 
