The relationship between pre‐oviposition flight behaviour and reproductive timing in whitefly parasitoids

Although the timing of oögenesis appears to be a major life‐history organizer in the parasitoid Hymenoptera, relatively little is known about how this trait correlates with population dispersal by flight in these wasps. Pre‐oviposition flight behaviours of 1‐day‐old female wasps in a vertical flight chamber are measured to test correlations between these traits and with reproductive timing. The focus of the present study is on two genera of whitefly parasitoids (Encarsia and Eretmocerus) that differ in reproductive timing when feeding on a shared host (Bemisia tabaci). The two Eretmocerus species engage in vertical flight within 3 min of release far more frequently than the three Encarsia species. Because the former typically possess a more time‐limited reproductive strategy than the latter, this lends support for a positive interspecific association between early‐life reproduction and early‐life flight incidence. Within species, however, egg load does not correlate with flight propensity for any of the tested species. Furthermore, in Eretmocerus eremicus, the relationship between effective flight distance (i.e. the product of vertical climb rate and flight duration) and egg load appears to be labile rather than fixed because different trials show evidence for either negative or positive correlations between these variables. The source of this context dependence may be variation in either biotic (e.g. longevity) or abiotic (e.g. temperature and relative humidity) factors.