Effects of temperature and diet on larval development of the endangered ground beetle Pterostichus isumiensis (Coleoptera, Carabidae)

Abstract

Insect growth is affected by various factors, and the elucidation of these factors is important from both basic and applied perspectives. This study examined the effects of temperature and diet on larval development of the endangered carabid beetle Pterostichus (Nialoe) isumiensis in laboratory rearing experiments. Three temperatures (10, 15, and 20 °C) and three diets (mealworms, dipteran larvae, and mealworms + dipteran larvae) were used in a 3 × 3 factorial design, and the survival rate and developmental duration of pre-overwintering stages (first and second instars) were compared. Survival was higher at lower temperatures, and the mealworm diet was associated with lower survival than other diets at lower temperatures. The developmental duration was shorter at high temperatures; at the same temperature, the mealworm diet was associated with a longer developmental duration. These results provide basic information useful for ex situ conservation of this endangered species, which may be required in future, and also inform several working hypotheses on the effects of temperature, diet, and their interaction on larval development in the Carabidae.