21 



Though these webs are very common upon the apple, they are even yet more numer- 

 ous on the wild-cherry, which appears to be their original food plant. They also attack 

 the hickory, ash, elm, willow, oak, birch, button wood and some other trees. 



The best remedy, probably, is to cut off the infested boughs and burn them. 



16. The Canker worm (Anisopteryx vernata,Veck ) — This insect, though very common 

 in many parts of the United States, and exceedingly destructive where it occurs, is not 

 often met with in Canada. The only native specimens we have seen, were sent us in 

 April, 1867, by our friend Mr. J. Pettit, of Grimsby, who stated that he first noticed them 

 late in November of the previous year, but that he found the females at different times 

 during the winter under the bark of trees. We gave an account of the insect at the time 

 in the Canada Farmer, (May 1st, 1867, p. 133,) from which we extract the following : 

 The Canker-worm belongs to a family of moths called Geometers, or " Measuring- worms," 

 or "Span-worms," from the mode of locomotion employed by the caterpillars in consequence 

 of the absence of legs under the middle portion of their bodies. They have three pairs 

 of legs near the head, and two pairs at the other extremity, and when walking, they draw- 

 up the hind legs close to the fore ones, doubling up the body in the form of an inverted 

 letter f[, then they stretch out the fore legs as far as possible, draw the hind ones up to 

 them again, and so on, looking just as if they were spanning or measuring the surface 

 they are on. The moths from which they are produced, are called the Anisopteryx ver- 

 nata, Peck ; the former name meaning " unequal-wing," because the sexes differ so much 

 in the dimensions of their wings, — in this case the jemale has no wings at all, and (like 

 the female of Orgyia leucostigma), would never be taken for a moth by one unacquainted 

 with entomology ; the latter name means "spring," because the moth is most commonly 

 seen in the spring of the year. 



The male moth has very delicate silky wings, broad in proportion to their length,, 

 which overlap each other when the insect is at rest ; the fore pair are ash-colored, with 

 a whitish spot near the tip on the front margin, and two indistinct zigzag whitish bands 

 across them, which are sometimes wanting ; the hind pair are paler and have a blackish 

 dot near the middle ; all the wings have rather long, pale fringes ; they expand about 

 an inch and a quarter. The wingless female is ash colored above and greyish beneath ; 

 of an oblong-oval form, tapering to a point behind. The accompanying wood-cut (Fig. 28,}* 



Tig. 28. 



I 



exhibits the insect in its various stages. (Fig. 28, (a) eggs, natural size ; (b) do. magni 

 fied j (c) caterpillar ; (d) cocoon ; (e) chrysalis ; (/) male moth ; (g) femde). 



Late in the autumn, after the first hard frosts are over, and mild genial days come 

 on, these moths issue from their pupa cases in the ground and continue to come forth, 

 whenever the weather is mild, all through the winter, appearing in the greatest numbers 

 early in the spring. The sluggish females at once crawl up the trunk of the nearest tree,, 

 where they are soon joined by the more active flying males ; after pairing has taken place,, 

 the female proceeds to the branches of the tree, where she lays her eggs, placing them in 

 clusters of from sixty to upwards of a hundred. From these the infant caterpillars hatch 

 out as soOn as the young leaves of the tree begin to expand and afford them a supply of " 

 suitable food. At first, from their small size, they attract but little notice, but during the 

 latter part of their larval existence, they grow rapidly and eat so voraciously as to divest 

 the tree of all appearance of greenness. When very young,"- — according to Harris — 

 " they have two minute warts on the top of the last ring, and they are then generally of 

 a blackish or dusky-brown color, with a yellowish stripe on eRch side of the body ; there 

 are two whitish bands across the head, and the belly is also \Vhitish. When fully grown, 

 these individuals become ash-colored on the back, and black on the sides, below which. 



