Australian Biological Resources Study

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October 2010 - Dr G. Cassis, University of New South Wales, Sydney, NSW


The Gerridae, or water striders, are a cosmopolitan family of gerromorphan semiaquatic bugs. The family presently comprises 67 genera and 751 species (Andersen 1982; Zoological Record 1980–1994; Henry 2009; Polhemus, J.T. pers. comm.).

Gerrids are elongate to ovoid and covered with several types of water-proof hairs, giving a velvety appearance (Andersen 1977). Species vary in length from 2 to 16 mm. The body is usually black or brown, occasionally with pale markings, and the venter is often silvery. The head is short and conical. The eyes are large and globular and ocelli are absent. The antennae and labium are 4-segmented. The pronotum is prominent, either covering the mesonotum or sometimes fused with it. The forewings lack a clavus or differentiated membrane. Wing polymorphism is common, with apterous, brachypterous and macropterous conditions known. The metathoracic scent glands are of the omphalium type, with a single sternal opening, two lateral glands and a median reservoir. The larvae lack dorsal abdominal glands. The legs are long and slender, with the hind femora extending beyond the abdomen, and are adapted for locomotion on water. The midlegs are primarily concerned with propulsion. The tarsi are 2-segmented and the claws of the forelegs are often inserted preapically (Slater 1982).

Gerrids inhabit the surface of lentic and lotic waters, including temporary pools, ponds, lakes, small streams and rivers. Halobatinae species are found in coastal waters or the open sea. Rhagadotarsus anomalus Polhemus & Karunarate is found in lakes, temporary waters or in quiet portions of flowing waters. Rheumatometra philarete Kirkaldy is found in large aggregations in the quiet parts of streams. Aquarius Schellenberg species occur in flowing waters and species of Limnogonus Stål occur in still waters.

Gerrids are obligate predators, feeding on organisms on or below the water surface. Prey items are held by the forelegs and pierced by the labium. Most gerrids lay their eggs below the water surface, mostly on vegetation. Halobatinae species lay their eggs on floating material and have been observed ovipositing on a living sea bird (Herring 1961). Andersen & Foster (1992) observed Halobates micans Eschscholtz eggs on a cuttlefish shell. Rhagadotarsinae lay their eggs in plant tissue. Cheng (1985) reviewed the biology of Halobates and Cheng & Schmitt (1982) described the biology of Halobates Eschscholtz species known from the Great Barrier Reef. The gerrid life cycle typically has five larval stages. Multivoltine species are known, particularly in tropical climates, where generations are continuous. In temperate regions, univoltine and bivoltine species are known and the adults are usually the hibernating stage. North American Gerris Fabricius species are known to overwinter under dead leaves, in holes, in stream banks and other sheltered places near water (Polhemus & Chapman 1979). Wing polymorphism has been examined in relation to habitat stability, photoperiod and temperature. Vepsäläinen (1971, 1973) reported aptery in European species found in stable habitats. Wing polymorphism has also been observed in different generations of the same species (Callahan 1974).

Hungerford & Matsuda (1960) gave an overview of the higher classification of the Gerridae, with keys to the suprageneric and generic groups. Matsuda (1960) provided a detailed description of gerrid morphology and divided the family into five subfamilies. Andersen (1975) revised the higher classification, raising three Gerrinae tribes to subfamily status. Calabrese (1980) provided a cladistic analysis of the gerrid genera of the world and discussed the biogeography of the group. Andersen (1982) reviewed the Gerridae, covering morphology, classification, phylogeny, ecology and biogeography. He claimed that gerrids are a monophyletic group on the basis of the frontal embryonic egg burster, absence of ocelli, prolonged mesothorax and two tarsal segments. He also analysed the gerrid subfamilies, refuting some of the sister-group relationships of Matsuda (1960) and Calabrese (1980). Andersen's classification recognises the following subfamilies: Rhagadotarsinae, Trepobatinae, Charmatometrinae, Cylindrostethinae, Eotrechinae, Gerrinae, Halobatinae and Ptilomerinae. Among the recent taxonomic works Polhemus & Polhemus (1993, 1994, 1995 1996) revised the subfamily Trepobatnae from Papua New Guinea with the review of worldwide fauna. Chen and Zettel (1998) revised the Oriental genus Ventidulus Distant. Polhemus (2001) and Polhemus & Polhemus (2001) revised species of the genus Ptilomera Amyot & Serville from Indochina and Papua New Guinea. Moralis-Costano & Molano-Rendon (2009) revised neotropical species of Tachygerrini. Andersen & Weir (2004) discussed the position if the family Gerridae among the other groups of Gerromorpha and incuded them to the identificational key of water bugs of Australia (Andersen & Weir 2004b).

The Gerridae are represented in Australia by four subfamilies, 11 genera and 37 species. The Gerrinae in Australia are represented by four genera and 14 species. Andersen (1990) reviewed the mostly Holarctic genus Aquarius, with two species known from Australia, A. fabricii Andersen from the Kimberley region and A. antigone (Kirkaldy), which is widely distributed in eastern Australia. Andersen (1975) revised the genus Limnogonus, recognising four Australian species, three of which are also known from the Oriental Region and/or Melanesia. The other Australian gerrines belong to Tenagogerris Hungerford & Matsuda and Limometra Mayr; Hungerford & Matsuda (1958) and Andersen (1964) revised the latter genus (as a subgenus of Tenagogonus Stål). Herring (1961) described all species, and provided a detailed discussion of their distribution and phylogeny. Malipatil (1988) reviewed the Australian species of Halobates, recognising 13 species in two ecological groups—coastal and open ocean. Polhemus & Polhemus (1991) reviewed some of the Australian Halobates and synonymised two Halobates species described by Malipatil. Andersen (1991) reviewed the genital morphology and phylogeny of Halobates, recognising a number of monophyletic species groups. He questioned the validity of the subgeneric classification, particularly the validity of Hilliella China, which is retained in the Catalogue. Andersen & Foster (1992) revised the Indian Ocean species of Halobates and Asclepios Distant. Andersen & Weir (1994a) described a freshwater halobatine Austrobates rivularis, from Cape York Peninsula, and provided a cladistic analysis of halobatine genera. Andersen & Weir (1994b) revised the Australian Halobates species, describing a new species from the Northern Territory, H. (Hilliella) lannae, redescribing all endemic species, and giving a phylogenetic analysis.

Polhemus & Polhemus (1991) reviewed some Trepobatinae, recording Stenobates Esaki from Australia, and describing two new species of the genus from northern Queensland and the Northern Territory; S. carpentaria is now assigned to Rhinometra Kirkaldy. Polhemus & Polhemus (1993, 1994) reviewed the world Trepobatinae fauna and described three species of Calyptobates Polhemus & Polhemus from northern Australia. The only other trepobatine known from Australia, Rheumatometra philarete, is found in eastern Australia. The Rhagadotarsinae is represented by one species, Rhagadotarsus anomalus, which is known from tropical Queensland and the Oriental Region.


General References

Andersen, N.M. 1964. The genus Tenagagonus Stål in the collections of the Zoological Museum of Copenhagen (Hemiptera: Gerridae). Entomologiske Meddelelser 32: 321-334

Andersen, N.M. 1975. The Limnogonus and Neogerris of the Old World. Entomologica Scandinavica. Supplementum 7: 1-96

Andersen, N.M. 1977. Fine structure of the body hair layers and morphology of the spiracles of semiaquatic bugs (Insecta, Hemiptera, Gerromorpha) in relation to life on the water surface. Entomologica Scandinavica 8: 301-316

Andersen, N.M. 1982. The Semiaquatic Bugs (Hemiptera, Gerromorpha). Phylogeny, adaptations, biogeography and classification. Denmark : Scandinavian Science Press Entomonograph Vol. 3 455 pp.

Andersen, N.M. 1990. Phylogeny and taxonomy of water striders, genus Aquarius Schellenberg (Insecta, Hemiptera, Gerridae), with a new species from Australia. Steenstrupia 16: 37-81

Andersen, N.M. 1991. Marine insects: genital morphology, phylogeny and evolution of sea skaters, genus Halobates (Hemiptera: Gerridae). Journal of the Linnean Society of London, Zoology 103: 21-60

Andersen, N.M. & Foster, W.A. 1992. Sea skaters of India, Sri Lanka, and the Maldives, with a new species and a revised key to the Indian Ocean species of Halobates and Asclepios (Hemiptera, Gerridae). Journal of Natural History 26: 533-553

Andersen, N.M. & Weir, T.A. 1994. Austrobates rivularis, gen. et sp. nov., a freshwater relative of Halobates Eschscholtz (Hemiptera: Gerridae), with a new perspective on the evolution of sea skaters. Invertebrate Taxonomy 8: 1-15

Andersen, N.M. & Weir, T.A. 1994. The sea skaters, genus Halobates Eschscholtz (Hemiptera: Gerridae), of Australia: taxonomy, phylogeny and zoogeography. Invertebrate Taxonomy 8: 861-909

Andersen, N.M. & Weir, T.A. 1997. The Gerrinae Water Striders of Australia (Hemiptera: Gerridae): Taxonomy, Distribution and Ecology. Invertebrate Taxonomy 11: 203-299

Andersen, N.M. & Weir, T.A. 1998. Australian water striders of the subfamilies Trepobatinae and Rhagadotarsinae (Hemiptera: Gerridae). Invertebrate Taxonomy 12: 509-544

Andersen, N.M. & Weir, T.A. 2004. Australian Water Bugs. Their Biology and Identification (Hemiptera-Heteroptera, Gerromorpha & Nepomorpha). Entomonographen Denmark : Apollo Books Vol. 14 344 pp.

Andersen, N.M. & Weir, T.A. 2004. Mesoveliidae, Hebridae, and Hydrometridae of Australia (Hemiptera: Heteroptera: Gerromorpha), with a reanalysis of the phylogeny of semiaquatic bugs. Invertebrate Systematics 18: 467-522

Anderson, N.M. & Weir, T.A. 2003. A new species of sea skaters, Halobates Eschscholtz, from Robinson River, Western Australia (Hemiptera-Heteroptera: Gerridae). Aquatic Insects 25(1): 9-18

Calabrese, D.M. 1980. Zoogeography and cladistic analysis of the Gerridae (Hemiptera: Heteroptera). Miscellaneous Publications of the Entomological Society of America 11: 1-119

Callahan, J.R. 1974. Observations on Gerris incognitus and Gerris gillettei. Proceedings of the Entomological Society of Washington 76: 15-21

Chen, P. & Zettel, H. 1998. A taxonomic revision of the Oriental water strider genus Ventidius Distant (Hemiptera, Gerromorpha, Gerridae). Tijdschrift voor Entomologie 141(2): 137-208 [Date published 1999]

Cheng, L. 1985. Biology of Halobates (Heteroptera: Gerridae). Annual Review of Entomology 30: 111-135

Cheng, L. & Schmitt, P.D. 1982. Marine insects of the genera Halobates and Hermatobates (Heteroptera) from neuston tows around Lizard Island, Great Barrier Reef. Australian Journal of Marine and Freshwater Research 33: 1109-1112

Herring, J.L. 1961. The genus Halobates (Hemiptera: Gerridae). Pacific Insects 3: 223-305

Hungerford, H.B. & Matsuda, R. 1958. The Tenagogonus-Limnometra complex of the Gerridae. Kansas University Science Bulletin 39: 371-457

Hungerford, H.B. & Matsuda, R. 1960. Keys to subfamilies, tribes, genera and subgenera of the Gerridae of the world. Kansas University Science Bulletin 41: 3-23

Malipatil, M.B. 1988. Two new species of Halobates Eschscholtz (Hemiptera: Gerridae) from Australia. Journal of the Australian Entomological Society 27: 157-160

Matsuda, R. 1960. Morphology, evolution and a classification of the Gerridae (Hemiptera-Heteroptera). University of Kansas Science Bulletin 41: 25-632

Morales-Castano, I.T. & Molano-Rendon, F. 2009. Revision of the genera Eurygerris and Tachygerris (Hemiptera: Tachygerrini) from the neotropical region. Revista Mexicana de Biodiversidad 80(2): 395-410

Polhemus, D.A. 2001. Review of the genus Ptilomera (Heteroptera: Gerridae) in Indochina, with descriptions of two new species. Journal of the New York Entomological Society 109(2): 214-234

Polhemus, J.T. & Chapman, H.C. 1979. Family Gerridae/water striders, pond skaters, wherrymen. pp. 58-69 in Menke, A.S. (ed.). The Semiaquatic and Aquatic Hemiptera of California (Heteroptera: Hemiptera). Berkeley : University of California Press.

Polhemus, J.T. & Polhemus, D.A. 1991. Three new species of marine water-striders from the Australasian region, with notes on other species (Gerridae: Halobatinae, Trepobatinae). Raffles Bulletin of Zoology 39: 1-13

Polhemus, J.T. & Polhemus, D.A. 1993. The Trepobatinae (Heteroptera: Gerridae) of New Guinea and surrounding regions, with a review of the world fauna. Part 1. The Metrobatini. Entomologica Scandinavica 24: 241-284

Polhemus, J.T. & Polhemus, D.A. 1994. The Trepobatinae (Heteroptera: Gerridae) of New Guinea and surrounding regions, with a review of the world fauna. Part 2. Tribe Naboandelini. Entomologica Scandinavica 25: 333-359

Polhemus, J.T. & Polhemus, D.A. 1995. The Trepobatinae (Heteroptera: Gerridae) of New Guinea and surrounding regions, with a review of the world fauna. Part 3. Tribe Trepobatini. Entomologica Scandinavica 26(1): 97-117

Polhemus, J.T. & Polhemus, D.A. 1996. The Trepobatinae (Heteroptera: Gerridae) of New Guinea and surrounding regions, with a review of the world fauna. Part 4. The marine tribe Stenobatini. Entomologica Scandinavica 27(3): 279-346

Polhemus, J.T. & Polhemus, D.A. 2001. A revision of the genus Ptilomera (Heteroptera: Gerridae) on New Guinea and nearby islands. Journal of the New York Entomological Society 109(1): 81-166

Slater, J.A. 1982. Hemiptera. pp. 417-447 in Parker, S.P. (ed.). Synopsis and Classification of Living Organisms. New York : McGraw Hill Book Co.

Vepsäläinen, K. 1971. The roles of photoperiodism and genetic switch in alary polymorphism in Gerris. Acta Entomologica Fennica 28: 101-102

Vepsäläinen, K. 1973. The distribution and habitats of Gerris Fabr. species in Finland. Annales Zoologici Fennici 10: 419-444


History of changes

Note that this list may be incomplete for dates prior to September 2013.
Published As part of group Action Date Action Type Compiler(s)
05-Dec-2012 05-Dec-2012 MODIFIED
15-Aug-2012 15-Aug-2012 MODIFIED
20-Oct-2010 20-Oct-2010 MODIFIED
12-Feb-2010 (import)