Moths 227 



cattle-ranges in New Mexico, and specimens are sometimes found 

 in southern Colorado. There is another Saturniid which de- 

 serves mention, because its generic name is derived from that of 

 the State. Coloradia pandora of Blake has the broad upper wings 

 grayish, with a black discal spot, the lower wings much paler. 

 The larva feeds on pine. The moth is occasionally found in 

 Boulder, having been taken by G. Hite and Miss A. O. Todd. 



The family Arctiidae derives the name from the Greek word 

 meaning a bear, the very hairy caterpillars being called "woolly 

 bears." We have numerous species, some of them beautifully 

 colored and marked. The salt-marsh moth, Estigmene acraea, 

 is very common. It has the greater part of the abdomen yellow, 

 with a row of black spots down the middle. In the female the 

 wings are white with small black spots, in the male the fore wings 

 are white, the hind wings yellow. Diacrisia virginica of Fabricius 

 is a smaller white moth, with hardly any dark markings. In 1910 

 the larvae were found on mint (Mentha) in Boulder. They have 

 two forms, appearing different, but they proved to belong to one 

 species by Mrs. Cockerell, who raised both from one batch of 

 eggs. The commoner form of caterpillar has the head light 

 yellow, the back blackish (marbled with dilute black on a gray 

 ground), sides with a broad dull yellow stripe, under surface lead- 

 gray; thoracic legs pale yellowish; tubercles with large spreading 

 bunches of light ferruginous hair, with a good many black hairs 

 intermixed. In the other form the head is dark reddish, the mouth 

 yellow; hair of body black anteriorly and posteriorly, but on middle 

 segments partly ferruginous; yellow lateral band reduced; thoracic 

 legs yellow. The general appearance is very dark, in strong con- 

 trast to the other form of larva. These differences are interesting, 

 as showing that an insect may have two forms, very distinct in 

 the larva, but not at all differing in the adult. In other cases the 

 larvae are alike, but the adults show great variation. Isia Isa- 

 bella of Abbot and Smith is another common moth. It is clay 

 yellow, sometimes slightly flushed with pinkish. There is a row of 

 black spots down the middle of the abdomen. The larvae are 

 often common on the campus of the University of Colorado and 

 are easily recognized by the fact that they are densely covered 

 with long hair, which is reddish brown in the middle of the body, 

 but black at each end. 



