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

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Nymphs trap fine, particulate, organic material and algae with their mouthparts and fore legs (Campbell 1985). Nymphal development takes from 6 months to 2 years with emergence in most species occurring directly from the water surface (Campbell 1986). The emergence period is variable ranging from 4 months (November-March) for C. giganteus to 9 months (August-April) for C. haleuticus (Campbell 1986). Adults of C. haleuticus and at least one other undescribed species from the Snowy Mountains swarm above streams at dusk, often using bridges as markers. Females of C. munionga produce between 2000 and 12 000 eggs. Eggs of all species have unusual adhesive structures, and in at least one species there appears to be an 11 month egg stage or early nymphal diapause.


Coloburiscoides (5 spp.) are known from the south-eastern mainland (Lestage 1935; Riek 1955, though Riek's redefinition of Coloburiscoides is incorrect and applies to the New Zealand genus Coloburiscus ). Coloburiscoides nymphs have mouth-parts modified for filter feeding and 2 pairs of finger-like, oral gills as well as abdominal gills. Each of the latter consists of a bifid, spinose lamella and a basal tuft of filaments. Both the oral gills and the tufts of the abdominal gills have large numbers of chloride cells and appear to be both osmoregulatory and respiratory (Filshie and Campbell 1984). The spinose structures of the gills appear to anchor nymphs beneath rocks in stony, upland streams.

  • Coloburiscoides giganteus  nymph

  • Coloburiscoides sp.