46 
Psyche 
[March 
of about 6 miles per hour at three feet above the ground, we have 
consistently observed cessation of spontaneous flights and at ten miles 
per hour cessation of 90% of the escape flights. The insects creep 
into rock crevices and into clumps of grass, becoming difficult to dis- 
lodge. A. cons per sa is reluctant also to fly more than a few feet over 
a radically changed substrate such as an asphalt road. A typical 
maneuver of this insect is to curve back and land at the grassy side, 
even if it means coming back to the investigator. Stronger fliers, such 
as X anthippus , Craty pedes, and Circoteitix show no reluctance to 
fly over such changes in substrate. 
Long escape flights of several hundred feet with the wind will 
occur in response to strongly disturbing stimuli. These escape flights 
are silent and can occur at lower temperatures than the normal 
lower threshold of the spontaneous flights. However, our studies 
indicate that males seldom move more than two hundred feet and 
tend to stay within the area of the sub-deme cluster. Long escape 
flights are rare and usually occur in response to unusual harassment — 
as by the investigator. On the other hand, spontaneous crepitating 
flights by the males are frequent during the four-week mating and 
egg-laying season. As the population ages, however, males show de- 
creasing persistence in courtship and make fewer flights. Whatever 
dispersion of A. conspersa by flight occurs, then, is restricted to a 
relatively short session in the Spring and may include the very infre- 
quent escape flights of males and young females. Nothing is known 
about the vagility of nymphs. 
The preferred food plants of A. conspersa are narrow-leaved grasses 
such as Poa palustris ; broad-leaved forbs are not eaten even in cap- 
tivity unless the insects are starving. Bare spaces between bunches 
of grass appear necessary for courtship interactions and moist ground 
nearby tends to lengthen the life span of the population by several 
weeks. However, the species is seldom found in tall grass meadow, on 
bare rock slopes, in thick forest or dense chaparral unless there are 
short-grass openings of at least an acre in area. Irrigated farm land 
with luxuriant meadows is likely to have A. conspersa only along 
the unirrigated road sides or in low density on rocky knolls which 
have much of the original grassland intact. Thus, although it is a 
common and wide-spread species, it tends to have rather restricted 
habitat preferences and, owing to its social behavior, tends to settle 
Explanation of Plate 6 
The Gunnison River within the Black Canyon viewed from Pulpit Rock 
on the South Rim. The rim walls rise 1700 ft above the river at this point, 
at this point. 
