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 Major Groups | Insecta (insects) | Hemiptera (bugs) | Belostomatidae


Major Group: Insecta
Order: Hemiptera
Family: Belostomatidae

Descriptive Features:

  • body elliptical, moderately dorsoventrally flattened
  • head with triangular anteoculus
  • eyes large
  • ocelli absent 
  • antennae usually 4-segmented, housed in grooves below the eyes, antennal segment 2 and 3 with lateral projections
  • pronotum divided into 2 lobes
  • hemelytral membrane with reticulate veins
  • scent glands present in Lethocerus, but absent in Diplonychus, nymphs lack dorsal abdominal glands
  • metepimeron extends posteriorly over abdominal sterna 1-2 or 3, fringed with long hairs
  • forelegs raptorial, strongly incrassate, with femora often grooved to accept tibiae
  • foretarsi 1- (Diplonychus) or 3-segmented (Lethocerus)
  • mid- and hindlegs modified for swimming, flattened and fringed with hairs
  • abdominal segment 8 with 2 long flattened, retractile respiratory straps
  • Total length: 15 - 70mm
  • Taxonomic Checklist: Genera

    Distribution: Australia wide 

    Sensitivity Rating: SIGNAL grade 1

    Functional Feeding Group: predators

    Ecology: Instream habitat: Commonly known as ‘giant water bugs’, Belostomatidae species live in wetlands, ponds and lakes that have plenty of aquatic vegetation in the littoral zone.
    Feeding ecology:Belostomatid bugs are good swimmers, able to chase after their prey over a short distance, although they spend most of their time hanging in the water column waiting for an opportunity to catch prey. They are voracious predators, becoming a nuisance in fish farms and can inflict a painful bite upon humans. Their large size means belostomatid bugs are often at the top of the food chain and are one of the few invertebrates that can readily feed on small fish as well as other invertebrates, including their own species.
    Life history: The female Diplonychus lays her eggs on the back of the male. In this position they are safe from the male and other predators. The male strokes the eggs with his hind legs to maintain a fresh flow of water, but if an egg gets dislodged he readily eats it. Belostomatid nymphs stay away from adults to avoid being eaten. Males have been reported to make stridulatory sounds to attract females. They initiate mating by "display pumping" or rhythmical push-up-like body movements near the surface of the water.
    Diplonychus eques  

    adult male carrying eggs

    Information Sources: Andersen & Weir 2004, Cassis & Gross 1995, Lansbury & Lake 2002, Gooderham & Tsyrlin 2002, Wade et al 2004
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