•>;. 



ON CANKER WORMS. 



I;Y \V. SAUNDERS, LONDON, ONT. 



Late in the fall, when many of the leaves have fiillen and severe frosts have cut 

 everything tender, and all nature begins to look bleak and cheerless, a walk in the woods 

 on a sunny afternoon is not without its charms. Here and there slender, delicate, silky- 

 winged moths may be seen flitting about, apparently in a somewhat aimless manner, 

 enjoying the genial sunshine. On capturing one, and examining it closely, we find it to 

 be a very handsome and delicately-marked moth, with wing structure so thin as to be 

 almost transparent, and one is naturally led to inquire how it is that so frail a creature 

 should select so frost}- and bleak a season in which to appear among us. In reply to this 

 reasonable inquiry it may be said that appearances are deceptive ; that delicate as the struc- 

 ture of this moth appears to be, it is nevertlieless one of the hardiest of its race, requir- 

 ing, indeed, some con.siderable degree of cold for its perfection. These moths are the pro- 

 duet of the Canker Worm, and the winged specimens are all males. 



During the last few j'l ars several valuable papers have lieen published on the insects 

 known as Canker Worms, in which has been detailed much hitherto unknown in connec- 

 tion with their life hi-story. Prominent among these is a ])apcr byC. V. Riley, St. Louis, 

 Mo., in his Second Re^3ort on the Noxious Insects of the State of Missouri, and a recent 

 paper of his in the Transactions of the St. Louis Academy of Science ; also an article by 

 B. P. Mann, in the Proceedings of the Boston Society of Natural History, and another by 

 H. K Morrison, in the 6th volume of the Canadian Entomoloyist. In the following sum- 

 maiy of what is known respecting these insects we shall make free use of these, as well as 

 previous writings, without further acknowledgment. 



In 1795, Prof. W. D. Peck wrote his " Natural History of the Canker Worm." This 

 paper was awarded a prize by the Massachusetts Society for Promoting Agriculture, and 

 was published in their Proceedings. At this early period all the insects passing under 

 this name were supposed to be one and the same species ; but later and more careful ob- 

 servation has led to a modification of this view, and it is now universally admitted that 

 there are two distinct species possessing similar habits, and having many points of re- 

 semblance— one producing the perfect insect in the fall, the other partly in the fall and 

 partly in the S[)ring, the former species being knowu under the name of Anisopieryx pome- 

 taria, the latter as a Varnata. The latter species will first claim our attention. 



Aniwpieri/x Vernata. 



At // fig. 1 we have a representation of the egg of this species 

 ori an enlarged scale, the natural size being shown in the small 

 cluster adjoining. In form it is not unlike a miniature hen's 

 (gg, but is of a very delicate texture and pearly lustre, with ir- 

 regulai- impressions on its surface. The eggs are laid in masses, 

 witiumt any regularity or order in their arrangement, often as 

 many as a hundred together, and secreted in the crevices of the 

 •jark of the trees infested. The eggs are usually hatched between the first and middle 

 Of May, about the time when the young leaves of the ajiple tree begin to push from the 

 bud. The little canker worms, on making their escape from the egg, cluster upon anil 

 ct'usunu' the tender leaves, and on the approach of cold oi' wet weather creep for shelter 

 into the liosoni of the expanding bud or into the opening (lowers. The newly-hatched 

 caterpillar is of a dark olive green or brown colour, with a black shining head, aiul a 

 horny plate of the same colour on tlie second segment. When lull grown they measure 



IX 



