We observed activity and behavior of Trimerotropis pallidipennis in the field and constructed time-activity budgets during June–July 2003. Grasshoppers began to walk once site temperatures (shaded air temperature 1 cm above soil surface) reached 18.6°C, foraging began once temperatures reached 24.2–31.7°C, and courtship began once temperatures reached 30.3–36.4°C. Mating and oviposition occurred when temperatures reached 30–40°C. Quiescence occurred most often at the lowest and highest site temperature categories (20–25, 25–30, and 45–50°C), and the highest frequency of foraging occurred most often at temperatures of 35–40°C. We observed no clear diurnal patterns for walking in grasshoppers, and found no significant difference between frequency of activities in morning and evening, within the same temperature ranges. Males rested, courted, and groomed significantly more frequently than females, and females foraged significantly more than males. Activity patterns, especially quiescence and foraging, were influenced much more by environmental temperature than by time of day.