THE CANADIAN ENTOMOLOGIST 425 



always found swarming actively above pools, streams, lake-shores, 

 and also above roadsides during sunset, but in cold weather the 

 swarm is not likely to be seen and their activities have evidently 

 been checked by the low temperature. On Aug. 27, at 5.30 a.m., 

 when the temperature was about 5 degrees C, I observed imagines 

 torpid and unable to fly even when disturbed. On slightly windy 

 evenings, the swarm either does not occur or has a very short 

 duration. Smoke has the same effect on a swarm. It has been 

 found several times that in the Cascadilla Gorge the swarm was 

 often dispelled by smoke from camp-fires even when at a consider- 

 able distance. 



Number of Generations. — My observations made in the sum- 

 mer and fall of 1915 indicate that probably five generations may 

 be developed in this locality. The number of generations was de- 

 termined by the finding of egg-masses in ponds and dishes from 

 time to time. The first appearance of egg-masses was in May 

 and the first two weeks of June, the second in the last part of July, 

 the third in the second week of August, the fourth in the first two 

 weeks of September and the fifth in the middle of October. 



Enemies. — ^The midge is apt to be attacked by enemies through- 

 out all the stages in its life-history. The eggs are attacked by the 

 fungous disease as already mentioned. I have observed a young 

 larva preyed upon by a Cyclops. The crustacean held up the 

 thorax of the little larva with its mouth-parts and gnathopods, 

 sucking out the body fluids. After a while, the Cyclops shifted 

 its mouth-parts toward the caudal end. By so doing, within ten 

 minutes, the entire body of the larva was emptied of its contents. 

 At this point another Cyclops came to participate in this work 

 and wrested the prize away from the original possessor. 



I have occasionalh- witnessed bats which preyed upon the 

 'adults by flying across the swarm. 



Bibliography. 

 1. Burrill, A. C. 



1913. Economic and Biologic Notes on the Giant Midge 

 (Chironomus plumosus Meigen). Bull, of the Wis. 

 Nat. Hist. Soc, Vol. X, Nos. 3-4, pp. 124-163. 



