The impact of diapause on the evolution of other life history traits in flesh flies.

Abstract

Flesh flies (Sarcophagidae) collected in Costa Rica and Panama lack the pupal diapause that is characteristic of flesh flies from the temperate zone and tropical Africa. The absence of a diapause capacity in the neotropical species correlates with several other life history traits: in most species the post feeding wandering phase of the third larval instar is longer and duration is more variable, adult life is longer, clutch size is smaller, and more clutches are produced. Among species that have the capacity for diapause, risk is invested primarily in the diapausing stage and other life stages are brief. Though diapausing species are short-lived, they produce as many or more progeny than nondiapausing species by increasing clutch size. The slower and more variable developmental rate and increased adult longevity desynchronizes development and permits the nondiapausing species to spread an environmental risk over different stages of the life cycle, thus offering an alternative to diapause. Other traits such as body size, developmental velocity, thermal constant thresholds, thermal constants, age at first reproduction, and the interval between clutches do not appear related to the capacity for diapause.