What Bug Is That? The guide to Australian insect families.

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Noterids usually inhabit the margins of shallow ponds, where adults and larvae are commonly found among the roots of floating or emergent aquatic plants. Larvae of some species obtain air by tapping plants with the aid of the spiracle-bearing siphon at the end of the abdomen. Little is known of the feeding habits, but it is generally thought that noterids are detritus feeders. Known pupae are contained in air-filled cocoons attached to the roots of aquatic plants.


Adult noterids are distinguished from Dytiscidae by the greater convexity of the dorsal surface, longitudinally oriented, hind coxal plates, and absence of a scutellum (present in almost all dytiscids). Also, the prosternal process is moderately broad and abuts on the metasternum, forming with it and the hind coxal plates a flattened keel. Larvae with very compact, fusiform shape, short legs, very short urogomphi, and mandibles broad at base and non-perforate. As in Dytiscidae, the posterior spiracles are placed close together at the end of T8, which forms the apex of the abdomen.


The family is widely distributed throughout the warmer parts of the world, and the Australian species, belonging to the genera Hydrocanthus , Canthydrus , Notomicrus and Hydrocoptus , occur primarily in the northern part of the continent. [Balfour-Browne and Balfour-Browne 1940; Beutel and Roughley 1987.]