38 



STATE POMOLOGICAL SOCIETY. 



black near the apex. Across the primaries of the male pometaria (see fig. 2, a) 

 are two white wavy lines, the outer one containing a heavy white dash at the ante- 

 rior border, which is more distant from 

 the outer border, being broken from the 

 main line. The female of vernata has a 

 black stripe on the back, and a two-joint- 

 ed ovipositor (see fig. 1, e), both of which 

 are wanting in pometaria. The cocoons 

 of vernata arc of brittle earth, only lined 

 with a few silken threads, and are thus 





FIG. II, ANISOFTERYX FOMETAKIA. 



a, male; b, female; c, antenna of female. 



easily broken, while in the pometaria they are composed largely of tough silk, 

 and will bear considerable pressure. The chrysalis of the female vernata is des- 

 titute of wing sheaths, while, strange as it seems, these are present (see fig. 4, 

 (j) in the pometaria. May not these, like the splint bone of the horse, bear 

 record of a progenitor which had these organs well developed? The terminal 



spine of vernata is simple, while in the chrysalis of 

 pometaria (see fig. 4, g and h) it is forked. The larva 

 of vernata (see fig. 3, a) has only ten legs, while in the 

 pometaria (see fig. 4, /) there are twelve, the extra 

 pair being on the eighth ring or segment. Prof. Ililey 

 states that the head of vernata is more distinctly mot- 

 tled with black. The character of the stripes (see fig. 

 3, c and d. anil fig. 4, c and <J) differ greatly in the 

 ciuste^;%ind g I, I a^ofntshow ( .^ ar V3e of the two species, but are subject to much varia 



ing back and side. ' 



FIGURE III. 



but <jrow lighter with 



tion in both. In vernata they are at first quite dark, 



age. 



The 



Qcrcra 



Of 



FIGURE IV. 



6, top of same; c ami d, back and 



vernata (see fig. 3, b) are oval and laid in 

 irregular masses in some concealed spot, as 

 under the scales of bark, and are not cov- 

 ered with glue. Those of pometaria (see 

 fig. 4, a, b, and e) are of the form of a 

 flower-pot, with a puncture in the center of 

 the top and a distinct ring of brown sur- 

 rounding these about half-way from center^ 

 to circumference. These are deposited on 

 the branches of the tree in exposed situa- .<*> e s§>. 



,. , , ., . ., , l ,. side ot joint; e., egg cluster; /, larva; g, 



atlOllS, placed Side by Side Close together, chrysalis of female; A, spine of same. 



with much regularity, and are well covered with glue. Prof. Riley states that 

 vernata deposits from 50 to 150 eggs, while pometaria deposits from 100 to 200. 

 Let us next give attention to the different stages of these two insects, that we 

 may discover aught of difference that exists in the time of appearance in any of 

 the stages from egg to imago. A. vernata, or the spring canker-worm, as we 

 might suppose from the name, comes forth as a moth (see iig. 1, a and b) in 

 early spring during the month of March.* The eggs (fig. 3, b) are now laid, as 

 will be remembered under bark-scales, old bird-nests, in clumps of dry leaves, 

 etc., where the females (Iig. 1, b) by use of her two-jointed ovipositor (iig. 1, e) 

 is well fitted structurally, to place them. .1. pometaria or the fall canker- 

 worm (Iig. 2, a and b), on the other hand, comes forth for the most part in 

 October and November, a few may delay (ill spring. I have often seen the 



* Daring the past winter, 1877, these come forth in February, the development being accelerated 



doubtless by the warm, beautiful weather, which is more characteristic of a Michigan April. 



