Influence of temperature on the development, reproduction, and life table of Calliptamus italicus (L.) (Orthoptera: Acridoidea)

Abstract

Calliptamus italicus is a migratory species of grasshopper that can cause serious damage to grasslands in Xinjiang, China. In this study, we examined the effects of different temperatures (23, 26, 29, 32, and 35°C) on the lifecycle and life table parameters. The results showed that temperature strongly influences the growth and development of C. italicus. At temperatures ranging from 23 to 35°C, the development time was negatively linearly related to temperature (P<0.01). The time of development from an egg to an adult (pre-oviposition) ranged from 86.8d at 26°C to 40.6d at 35°C, and no oviposition occurred at 23°C. An average of 687.1degree-days was required for complete development to occur above the lower threshold temperature (18.3°C). Egg hatching rates and nymph and pre-adult survival rates were lowest at 23°C (95.6%, 72.6%, and 0%, respectively) and highest at 32°C (97.8%, 86.2%, and 88.7%, respectively). The mean total fecundity ranged from 41 eggs/female at 26°C to 55 eggs/female at 32°C. The sex ratio (% females) ranged from 30 to 52%. The intrinsic rate of population increase (rm) at the different temperatures ranged from 0.0020 to 0.0447d−1, with the highest value recorded at 32°C. These results indicate that temperature significantly affects the biology of C. italicus and that the optimal temperature range for its development is 26–32°C.