This is the first guide to the aquatic Heteroptera of Singapore and Peninsular Malaysia to be published as a series in the Raffles Bulletin of Zoology. The families Gerridae and Hermatobatidae are included. Gerridae, with 22 genera and 54 recorded species, are probably the commonest aquatic bugs in our regions whereas Herrnatobatidae, a monotypic family, is represented by only 2 species. We have provided lists of known local species of Gerridae and their habitats, a key to genera as well as keys to species where applicable. We have also included illustrations of representative species of each genus, some of the key characters used, and notes on biology and habitat.

This is the first of a series of publications planned as guides to aquatic Heteroptera of Singapore and Peninsular Malaysia to be published in the Raffles Bulletin of Zoology. A key to families and a list of known genera with number of described species for each genus are given.