226 Zoology of Colorado 



three light bands, the innermost short. There is a third, much 

 rarer, species found as a larva on tomato. The hind wings are 

 crossed by two white stripes, and the abdominal spots are creamy 

 white, not yellow. This is Mesosphinx separates, the genus dis- 

 tinguished from the related Sphinx principally by the characters 

 of the larva and pupa. 



Rivalling the Sphinx moths in size and beauty are the 

 Saturniidae, or large silk moths. In the foothills and mountains 

 of Colorado, a common species is Samia gloveri, known by the 

 plum-colored inner half of the wings. The large light green larva 

 has conspicuous red or yellow prominences; it is especially found 

 on choke-cherry. In the Eastern States, this species is repre- 

 sented by the well-known Cecropia moth, which has brick-red 

 marks on a dark brownish-gray ground, and lively red thorax 

 with a white collar. This species (Samia cecropia) extends to the 

 eastern plains of Colorado, and the larvae were reported by Henry 

 Weeth to be very destructive at Peetz. Our other very large 

 silk moth is the Telea polyphemus, common east and west. It is 

 warm reddish, or sometimes (variety olivacea) olivaceous, the 

 wings with translucent patches, that on the hind wings on a large 

 black patch, the center suffused with blue. The larva of Telea 

 is easily known from that of Samia by the reddish-chestnut head. 

 A much smaller though good-sized insect is the Io moth (Auto- 

 meris io color adensis), our form being racially distinct from that 

 of the Eastern States. The hind wings have a large round black 

 patch, in the center of which is a white mark, surrounded by a 

 purplish suffusion. Under a lens, from one angle we see merely 

 white scales on a black ground, surrounding the white mark, but 

 from a different direction the surface appears beautifully purple. 

 The scales of this part of the wing are short and broad, but the 

 black ring is overlaid with long strap-shaped scales. The females 

 have an expanse of about three and one-half inches, the males 

 about two and three-quarter inches; in the former the front wings 

 are deep reddish, more or less plum color, in the latter they are 

 yellow. Thus the sexes look like quite different species. The 

 green larva is covered with clusters of spines, which have stinging 

 properties. It may be found on various woody plants. A very 

 pale-colored member of this family, Hemileuca oliviae, comes from 

 a larva which feeds on grass. It has been very destructive to the 



