84 



CEREAL AND FOEAGE INSECTS. 



discharged her supply of eggs, attention having been first directed 

 to them by the worn and ragged appearance of the wings of the female 

 thus found. The females that take to wing before mating and alight 

 in the borders of, or outside, infested territory, must necessarily mate 

 with worn wings, since their long flight must have its effect on their 

 appearance. 



A table on page 88 gives the results of a large series of dissections 

 which seem to prove the existence of more males than females wher- 

 ever examination was made. During the first week of emergence in 

 1909 the males outnumbered the females at least three to one. 



The date of the beginning of adult emergence in former years is 

 not known. In 1908 the moths are said to have appeared about 

 October 1. In 1909 the first adults, two males, were seen October 

 1, and it is probably safe to consider this as the average date of 



Fig. 4G. — The New Mexico range caterpillar: Moths mating. Reduced. (Original.) 



The adults continue to appear until the middle of November, 

 unless, as in 1909, the cold and snow put an earlier stop to their 

 emergence. As far as can be learned from residents of New 

 Mexico, no belated Hemileucas appear in the spring, but all that fail 

 to emerge in the fall perish, in the chrysalis, during the winter. 



The life cycle of the species is illustrated by figure 47. 



CHARACTER OF FLIGHT. 



When fairly on the wing the flight of the Hemileuca moths is strong 

 and persistent. The males are much more active than the females, 

 and are at times very difficult of capture except by strategy. They 

 usually fly near the ground, moving across the country by a series 

 of zigzag back-and-forth flights, always working into the wind and 

 never alighting except in the immediate neighborhood of a virgin 

 female. They carefully reconnoiter every plant, and fly especially 

 about the tallest objects in the landscape as they search closely for 

 the female, guided, apparently, by odor. A person standing erect 

 is the object of much of their attention, and the swarm of " purring" 



