Do behavioural and life-history traits vary with mate-guarding intensity in libellulid odonates?

Abstract

It has been demonstrated that in libellulid dragonflies the distribution of eggs during oviposition and the offspring size vary with the type of mate guarding during oviposition (non-contact guarding and contact guarding). In this study, we investigated the hypothesis that oviposition behaviour and life-history traits also differ between these two guarding types. Therefore, we studied oviposition behaviour and life-history traits in six species of a dragonfly assemblage of the Namib Desert. Among the oviposition behaviours, oviposition duration and number of pond changes differed significantly between the guarding types. Clutch size did not differ between the guarding types, whereas some offspring characters, namely egg width, temperature sum to hatch, and larval head width, differed between the guarding types. Eggs of tandem species (those performing contact guarding) were larger, which might explain differences in all other offspring characters studied; bigger eggs need a lower temperature sum for egg development, result in bigger larvae, and have a faster growth rate, all traits that might be seen as an adapation to temporary waters, which are major habitats of the tandem species. This observation is discussed in the light of different dispersal strategies between the species performing different guarding types.