Characterization of the larval stages of Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) using head capsule width.

The mean width (n = 5) of the cephalic capsule instar of Alphitobius diaperinus was determined. The larvae were reared at 27 degrees C (+/- 0.1 degrees C). The result showed that A. diaperinus has eight larval instars. The head capsule of the 1st instar larvae measured x = 0.228 (SD = 0.0192) and the last instar larval measured x = 1.339 (SD = 0.0436). The developmental rate, determined by Dyar-Hutchinson's rule, was 1.29. These data may be useful for studies on phenology and age structure of A. diaperinus in the field.