NEW MEXICO RANGE CATERPILLAR AND ITS CONTROL. 



Inside this cocoon the pupa is formed. The pupa^ is dark brown 

 in color, more or less cone-shaped, and from 1 to V 2 inches long. It 

 is this process of " spinning up" that causes the matted and distorted 

 appearance of the range plants from late August to the end of the 

 year. The pupal period lasts for a month or six weeks and then the 

 moth comes forth. 



Moth, or parent insect.— The moth (see figs. 6 and 9), or parent, 

 when freshly emerged bears only short, stubby wings, and may be seen 

 during the early part of 

 the day clinging to a 

 grass or weed stem sit- 

 uated near its former 

 cocoon. After a few 

 hours the wings be- 

 come fully developed 

 and the moth takes 

 flight. Mating occurs 

 very soon after emerg- 

 ence from the pupa, 

 and within 24 hours the 

 female deposits her eggs 

 for next year's brood 

 of range caterpillars, 

 after which she usually 

 dies very quickly. In 

 the moth stage this in- 

 sect does not consume 

 any solid food. Most 

 of the moths emerge 

 and deposit their eggs 

 during the period be- 

 tween September 10 

 and November 15. 

 They are most active 

 just before sunset and 

 are often so numerous 

 as to give the impres- 

 sion of a snowstorm. 



The male and female 

 moths differ in color and size. The male moth measures about 2 

 inches from tip to tip of the wings ; his wings are white or light gray, 

 and his body is covered with long, brick-red hairs. The female 

 moth is larger than the male, being generally 2\ to 3 inches from 

 tip to tip of the wings ; her wings are reddish gray or dark brown 

 and her robust body is dark reddish brown with white stripes on 

 the lower side. 



Fig. 8.— The New Mexico range caterpillar: A characteristic mass of 

 cocoons in a single plant of Gntierrezia. Reduced. (C. N. Ainslie.) 



