Gerrinae is a subfamily of water striders consists of thirteen extant genera in two tribes and three fossil genera. The subfamily includes some of the best-known species of Gerridae and the largest species, Gigantometra gigas.

Description

Like all water striders, Gerrinae have two antennae, a narrow thorax, and six legs, which bear hydrophobic microhairs that allow them to walk on water.

Members of the Gerrinae subfamily are characterized by having long slender bodies. Typically, juvenile Gerrini range from lengths of 1 to 13 mm and widths of 0.5 to 3 mm. Adult lengths are 4 to 17 mm and widths 1 to 4 mm. Notably, these striders share similar sizes with the Cylindrostethinae and Ptilomerinae, subfamilies within the Gerridae family.

Habitat

Gerrinae are aquatic insects and are found in inland waters, inhabiting ponds and streams. They can be commonly found throughout the most of the world's freshwaters. While they often aggregate, these insects prefer not to live in close, compact groups.

Their most common source of prey are smaller insects. They will usually only go after anything that is helplessly stuck in the water. Cases of cannibalism during food shortages have been recorded, with young nymphs and weaker adults often falling victim.

Taxa

The following tribes and genera are considered part of Gerrinae:

  • Tachygerrini Andersen, 1975 Eurygerris Hungerford and Matsuda, 1958 Tachygerris Drake, 1957
  • Extinct (fossil) genera †Electrogerris Andersen, 2000 †Palaeogerris Andersen, 1998 †Succineogerris Andersen, 2000 †Telmatrechus (Ypresian; Western North America)