Variation in life history parameters of Oryzaephilus surinamensis (L). (Coleoptera: Silvanidae)

Rates of survival and development of immature stages, and survival and fertility of adults of four field populations and two laboratory strains of Oryzaephilus surinamensis (L.) were compared. Population parameters of the field populations were generally similar, although one had a lower fertility rate. A strain which had undergone about 70 laboratory generations differed from the field populations in most characteristics; it had higher immature mortality, was slower to develop with more larval instars and shorter adult survival. A strain with 6 laboratory generations differed from the field populations in having more larval instars and prolonged development of females as larvae.

Population parameters and statistics for the three similar field strains and the long-term laboratory strain were respectively: immature survival, 77–86% and 61.5% larval instars, 4 and 5: immature development time 22–24 days and 30 days; net reproductive rate (Ro), 212 217 and 176; innate capacity for increase (r_m), 0.82–0.85 and 0.68 per week; and mean length of a generation (T) 6.3 6.5 and 7.6 weeks.