Studies on the phenology of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) in the Sudan Gezira

Abstract

The oviposition and development of Tribolium castaneum (Herbst) were studied in uncontrolled room conditions and at 25, 30, and 35°C at 70% relative humidity (r.h.). Both oviposition and development were most rapid at 35°C, and least at 25°C. Egg hatchability was consistently over 90%, but the egg incubation period was significantly affected by temperature. The mean larval duration was shortest at 35°C and longest at 25°C; at 30°C the duration approached that at 35°C. At 30°C most larvae had six instars, whilst at 25 and 35°C most had seven instars. Pupal development was similarly affected by temperature, being shortest at 35°C and longest at 25°C. The mean total developmental periods, from egg deposition to adult emergence, were 19.1 days at 35°C, 26.4 days at 30°C, and 45.6 days at 25°C. The mean thresholds of development, obtained graphically, for the egg incubation, larval, and pupal periods were 19.3, 18.0 and 18.5°C, respectively, whilst the thermal constants were 45, 219, 65 and 357 day °C for the egg, larval, pupal and total developmental periods, respectively.