FIELD BOOK OF INSECTS. 



the crescents on the wings vary from white (especially on 

 the hind wings) to reddish and are bordered with red and 

 black; outside the prominent white band there is a reddish 

 band (in 5. gloveri of the West this band is broader and 

 purplish gray although inside of the white band the wings 

 are red); the outer border of both pairs of wings is light 

 clay-brown. S. Columbia occurs in northern United 

 States (west to Wisconsin) and in Canada; it has a wing 

 expanse of only about four inches and no red margin to 

 the white cross band. 5. rubra of Utah and Wyoming 

 westward is about the size of Columbia but the general wing 

 color is rather uniformly light red; it lacks, as does also 

 gloveri, the round dark areas near the hind angles of the 

 fore wings. The larva of cecropia is about four inches long ; 

 green with bluish tints, especially along the back, two 

 rows of blue tubercles along each side, two rows of yellow 

 ones along the back, and two pairs of red ones on the 

 thorax. The large cocoons, which when cut open have 

 distinctly the appearance on one cocoon inside another, 

 are fastened to a branch, or other support, but not to 

 leaves. Some cocoons are much larger and puffier than 

 others, probably because the larvag which made them were 

 better fed. This species ranges from the Atlantic to the 

 Great Plains. 



I am sorry that such an authority as 

 Callosamia Holland should have called this species 

 (Plate XLII) the Spice-bush Silk-moth 

 when " Promethea" was already in common usage; further- 

 more he says, truly, that "The insects subsist in the larval 

 stage upon a great variety of deciduous shrubs and trees, 

 showing a special predilection for Lauracece, Liriodendron, 

 Liquidambar, and wild-cherry" (spice-bush and sassafras 

 belong to the family Lauraceas). The mature larva is 

 from two to three inches long; head, yellowish-green; 

 body, "frosted " bluish-green ; six rows of small black tuber- 

 cles; two pairs of red tubercles on the thorax; one yellow 

 tubercle on the eleventh segment; the legs and the anal 

 shield yellow. The cocoon is much like that of cynthia 

 but tends to be darker and slimmer and is not so likely to 

 have silk strands over the leaf. The general color of the 



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