Variations in the life-history parameters of Hemipyrellia ligurriens (Diptera: Calliphoridae) in response to larval competition for food

Abstract

Larval competition for food was of the typical scramble type. Survivorship remained high at densities up to 31 larvae g liver -1, but decreased rapidly as larval density increased further. Emergent adults were undersized with reduced fecundity and longevity. Variations in adult body size reduced the effects of competition on larval mortality. Females of dry weight corresponding to only 10.4% of the potential maximum emerged at the highest rearing densities of 128 larvae g liver-1, but these females had a nearly 4-fold increase in reproductive investment (per unit weight) compared to the largest individuals. Duration of larval development declined when competition was intense (ie at high larval densities). The short adult life of H. ligurriens, combined with the unpredictability of larval habitat availability, may reduce the value of long-range dispersal so that females "do better' by maintaining reproductive investment despite a concomitant decline in dispersal ability. -from Authors