THE CANADIAN ENTOMOLOGIST. 



habits are similar to those of the latter. It sometimes occurs about 

 London in such numbers as to strip the trees of their leaves, and the 

 moths are taken in the squares of that city, sometimes twenty or thirty 

 on one tree. 



The Champ de Mars, Montreal, is a favorite breeding place of ursaria. 

 The Lombardy Poplars growing in this locality are infested with them 

 year after year. In some seasons the trees are partially defoliated by the 

 larvae, and during the last week of April and the first of May the moths 

 are to be found in great numbers. This year they were a little later than 

 usual. On the 5th May I first observed them, many having just emerged 

 from the pupa, and resting on the tree trunks with unexpanded wings. 

 On the 6th I brought home two females, and placed them in boxes to 

 obtain the eggs. Two days afterwards each had laid about two hundred 

 eggs of a bright green color, globular, and without markings under a low 

 microscopic power. They were .04 in diameter, and laid (in each case) 

 principally in the narrow opening between the lid and side of the box. 

 The female has an ovipositor which can be extended at least a quarter 

 inch, for the purpose, perhaps, of laying her eggs in the interstices of the 

 bark, as they are deposited some time before the leaves expand. About 

 the nineteenth day the eggs changed color, and became steel blue. On 

 the 29th May they began to hatch out, just as the poplars were expanding 

 their leaves. The larvae were very active, and from the first had the 

 peculiar geometric habit of resting now and then with the body extended 

 full length in the air, supported only by the claspers. I turned them out 

 on a young plum tree, and they soon began to feed freely, and grew 

 vapidly. Strange to say, they quickly diminished in numbers, and but 

 few reached maturity. 



New-born larva. — .12 inch long, black, head large, with a few whitish 

 hairs ; front edge of first segment bordered with white, second and third 

 with white spiracles ; next five segments have two white spots on back, 

 one on each side around spiracles, with another white spot below. Legs 

 black ; body beneath black. 



Mature larva. — 2 to 2.50 inches long, general color drab or dingy 

 purple ; head of a lighter shade, and spotted with black. First segment 

 bordered in front with a yellow line, indented behind ; fourth to eighth 

 inclusive, each with six very small yellow tubercles, two on back, one 

 behind and one below each spiracle. Body striped from head to tail 

 with twelve reddish lines, each bordered on both sides by an irregular 



