Paternal Care in Giant Water Bugs

Abstract

We describe general biology of giant water bugs (Heteroptera, Belostomatidae), exclusive paternal care (back-brooding behavior in Belostomatinae and emergent-brooding behavior in Lethocerinae), and recent topics in sexual selection in this family. In the general biology, we introduced phylogenetic relationships of Belostomatidae within Nepomorpha and among Belostomatidae genera, distribution, food, behavior, and general egg morphology. After Smith’s evolutionary hypothesis (Smith RL, The evolution of social behavior in insects and arachnids. Cambridge University Press, Cambridge, 1997), feeding habit of Belostomatidae was revealed and the result agreed with his hypothesis. In the exclusive paternal care, we reviewed the role of paternal care, oviposition site selection, and evolution of sexual size dimorphism and its relation to the presence of paternal care. After controlling for phylogenetic signal, it seems that the infanticide phenomenon does not necessarily explain the origin of sexual size dimorphism biased toward females in Belostomatidae, since the ancestor of all Belostomatidae was most likely a non-brooder. Finally, we show the future direction of the study in giant water bugs: coevolution between male and female genitalia in Belostomatidae, allometry for sexual size dimorphism and its disagreement with Rensch’s rule, and phylogenetic test of predictions provided by Smith’s evolutionary scenario assuming alternative conditions (Horvathinia is an emergent-brooder, a back-brooder, or a non-brooder).