Muscle Regression in Belostomatid Bugs (Heteroptera: Belostomatidae)

Abstract

Differential flight muscle regression was registered in Belostoma elegans (Mayr, 1871) and B. oxyurum (Dufour, 1863). A two year survey in contrasting habitats showed the preference for the more stable ones by B. oxyurum, and the more unstable ones by B. elegans. Fibrillar muscles were regressed in most of the B. oxyurum specimens, and developed for flight in most B. elegans. No positive correlation between egg production and muscle regression was found in any species. IVth and Vth instar larvae of both species were raised up in laboratory under unstable conditions. When moulting to adult stage none had their muscles developed, suggesting that the muscle development should be achieved later. B. oxyurum with its muscles regressed was found in quiescence during a dry-up of a sampled environment, thus this species would have to survive unexpected changes this way, and B. elegans would emigrate flying. The differential muscle development is associated with the ecological strategies of these two species.