The genus Gerris was first described by Fabricius (1794) and previously recorded from Ceylon by Dohrn (1860). It was recorded from Burma, Malaya, Thailand and China and was also recorded from Himachal Pradesh, Uttar Pradesh, West Bengal, Rajasthan in India. It is a world wide distributed genus of sub family Gerrinae Leach,1815 of family Gerridae Leach,1815. The Gerridae is an important family of suborder Heteroptera. The family Gerridae is at present known by 9 sub families viz., Rhagadotasinae, Trepobatinae, Halobatinae, Ptilomerinae, Cylindrostethinae, Charmatometrinae, Eotrechinae and Gerrinae. This genus is represented in India by 7 species. It is very common in stagnant water of ponds and lakes. The genus Gerris is easily recognized due to intersegmental suture between mesonotum and metanotum laterally continuous with metathoracic spiracle. Metathoracic spiracle located very close to lateral margin of pronoutm. The female genitalia is well developed. Gerris adelaidis Dohrn was selected as the standard gerrid for the present study of morphological characters of taxonomic importance of the Gerridae.