24 



ENTOMOLOGICAL SOCIETY OF ONTARIO. 



appearance of the pest during the past three seasons, I wish to make a few remarks upon 

 the species which has been the cause of so much disfigurement of our shade and forest 

 trees. The past summer was the third in which the attack has been severe, but there are 

 indications that the crisis has been passed and that we shall probably next year have a less 

 numerous host at work. The species which has been infesting our disti'ict is that known 

 as the Fall Canker Worm, A. pometaria, and I am informed by my friend Mr. Fletcher, 

 who has a fuller knowledge of the lepidoptera, that the other species (vernata), does not 

 occur here. 



While a variety of trees have been more or less injured, it was easily observed that 

 the basswoods were one of the favorite objects of attack, and the large succulent leaves 

 of this densely foliaged tree were speedily riddled, and entirely eaten away by the 

 swarms of caterpillars. In 1892 the ash trees suffered very much, and in many localities 

 were also almost defoliated. In one locality especially, where some fine trees grew on 

 the margins of a low meadow, the excrement dropped by the feeding swarms pattered 

 like a heavy shower on the ground beneath, and walking beneath the trees was rendered 

 most unjjleasant on account of the scores of dangling worms, fallen from aloft and swing- 

 ing to and fro on their silken lines. One soon got liberally sprinkled with worms, and 

 at the same time had the unpleasant sensation of the threads across his face like so many 

 strong cobwebs. The caterpillars which had fallen were of course anxious to return to 

 the feast, and could be seen crawling upward upon every trunk. A natural result of this 

 upward movement was, that all that got on one's clothing soon reached the collar, where 

 they circled around in a most disagreeable manner seeking a way to go still higher, and 

 liable to be crushed by any movement of the head. 



This year the attack in that locality was much lessened, either through the influence 

 of predaceous and parasitic enemies, or by flooding of the ground in the winter and 

 spring. Groves of hickories {Carya amara) on the higher land adjoining, were pretty 

 well defoliated, but here the Canker Worms were assisted in their work of destruction 

 by several other species of caterpillars. The Canker Worms were most abundant during 

 the first week of June, but by the 20th they were mostly finished feeding and had 

 dropped to the ground. During the period of their presence upon the trees I tried to 



Fig. 1.3. 



Fig. 14. 



observe as often as .possible the enemies by which they appeared to be attacked, and it 

 has been encouraging to find that some of these have increased rapidly in numbers, con- 

 currently with the increase of the worms, This has been especially noticeable in the case 

 of the fine beetle Calosoma frigidum, Kirby, which belongs to the same section of the 

 genus as C. scrutator, Fig. 13, and C. willcoxi, the beautiful large green beetles which occur 

 plentifully in some parts of Ontario, but whose range does not extend as far eastward as 

 Ottawa. The tree climbing and larvfe-seekirg habits of these splendid insects are well 

 known, and frigidicm, which has a more northerly and easterly distribution, appears to 

 have the same arboreal and predatory habits. Our other common species, 0. calidum, Fig. 

 14, is essentially a ground beetle and is a most persistent destroyer of cutworms. While 



