The effects of temperature and food quality on the larval development of Gryllus bimaculatus (Orthoptera, Gryllidae)

Abstract

Newly hatched larvae of Gryllus bimaculatus were kept on five synthetic diets of different protein contents (5%, 15%, 30%, 40%, and 50% of dry weight) and at three temperature ranges until imaginal molting. Each temperature range encompassed a daily alternating temperature and the corresponding constant mean temperature (29/11° C-23° C, 33/15° C-27° C, 37/19dg C-31° C, LD16:8 h). The course of development of the larvae depends on both the temperature and the diet. The penultimate larval instar period served for estimation of development under all rearing conditions. According to weight gain, duration of development, mortality, and food conversion efficiency a dietary protein content of 30% was optimal under a constant temperature-regime; at alternating temperatures protein contents of 15%-50% were satisfactory for optimal development. The energy requirement for a gain of one gram of dry weight is greatest at P-5%-diet and lowest at P-30%-diet. The results are discussed in terms of their ecological and physiological importance for field crickets.