Observations on the life history of giant water bugs <i>Lethocerus</i> Mayr, 1853 (Heteroptera: Nepomorpha: Belostomatidae) in the Gangetic plains of India and Nepal

Abstract

Two species of giant water bugs Lethocerus were found in the Gangetic plains of northern India and Nepal. Lethocerus indicus is widespread, whereas a single record of Lethocerus patruelis confirms the eastern distribution range in Bihar. Four instars of aquatic nymphs occur exclusively in temporary shallow stagnant water bodies which harbor rich amphibian populations but lack permanent fish fauna. From mid-August to the first week of November adults fly. Later they live submerged in aquatic habitats of large rivers and permanent stagnant water bodies which harbor diverse fish fauna. Repeated findings of adults with ventrally attached egg-shaped pupae of aquatic mites (Hydracarina) suggest that these are host-specific ones of Lethocerus. Thus, the occurrence of protelean parasites on giant water bugs in the Gangetic plains is a previously unknown unique finding since apparently mites have been noticed only from other Nepomorpha families.