Some further observations on the effect of temperature on the fecundity and longevity of Dermestes lardarius L. (Coleoptera: Dermestidae)

The fecundity of Dermestes lardarius L. was determined on a diet of fish-meal, yeast and cholesterol at 65% r.h., 17.5, 20, 22.5, 25, 27.5 and 30°C. Pairs of adults were given a water drink and eggs removed twice weekly. The median life-span of adults was longest at 17.5 and 20°C (maximum of 223 days) and shortest, 56 days, at 30°C. At each temperature, except 30°C, 50% of the females lived longer than males. At temperatures ranging from 17.5 to 27.5°C some females laid much earlier than others and some individuals exhibited two periods of oviposition. The longest oviposition periods were recorded at 20°C and the shortest at 27.5°C. Temperature had a great influence on the numbers of eggs laid. The total yield of eggs reached a peak of 1261 at 20°C and then declined to 52 at 27.5°C. Fifty percent of the females failed to lay at 27°C and no eggs were laid at 30°C. Fecundity of the females was very variable (0–196). The temperature of 20°C seemed to be optimal for egg laying in this species.