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 Major Groups | Insecta (insects) | Ephemeroptera (mayflies) | Leptophlebiidae


Major Group: Insecta
Order: Ephemeroptera
Family: Leptophlebiidae

Descriptive Features:

  • dorsoventrally flattened bodies and heads
  • flattened legs with broad femurs
  • prominent lateral gills on abdominal segments 1-7 vaguely leaf-like
  • small, well developed backward pointing spines on edges of abdominal segments 7-9
  • caudal filaments with rings or whorls of setae
  • Total length: up to 20 mm
  • Taxonomic Checklist: Genera

    (formerly Koorrnonga)

    Distribution: Australia wide. Nousia is the only genus that is not endemic.

    Sensitivity Rating: SIGNAL grade 8

    Functional Feeding Group: scrapers, gathering collectors, shredders 

    Ecology: Instream habitat: Leptophlebiid nymphs generally occur in fast flowing upland streams but also live in meandering lowland rivers, lakes and reservoirs and artificial dams in semi-arid areas. Nymphs are found in log crevices, amongst macrophytes and debris, also on or under cobbles and bedrock. Only Atalophlebia australasica is common in small, temporary streams, some of which are completely dry for more than half of the year.
    Feeding ecology: Leptophlebiidae species are detritivores or herbivores. Most nymphs scrape the surface of gravel, rocks and logs feeding on algae and detritus. However, Atalomicria has very long maxillary palps with brushes for collecting detritus and nymphs of Neboissophlebia and Ulmerophlebia shred leaf accumulations.
    Habit: Nymphs appear to be mostly nocturnal. Flattened bodies enable the nymphs to cling to substrata and resist the force of fast flowing waters. Deleatidium and Kirrara nymphs also have broad gills that form a suction cup around the abdomen to help cling to rocks. Jappa and Ulmerophlebia are burrowing nymphs but only Jappa has a pair of horns projecting forwards from its head to aid in burrowing. Atalophlebia has feathery gills that increase the available surface area to extract oxygen from slow flowing waters.
    Life history: In North America, the female dips her abdomen into the water, releasing a few eggs at a time. Oviposition is usually completed within five minutes, during daylight. In Britain, eggs can be produced parthogenetically. The length of the egg phase is temperature dependant. Smaller mature larvae have fewer instars than larger mature larvae and the number of instars is not constant, ranging from ten to fifty. Over wintering can take place in either the egg phase or larval phase. For Australian species, final instar nymphs crawl out of the water before ecdysis. There are two adult stages; a sub-imago, which has incompletely developed reproductive structures, that usually lasts for 24 hours, and then an imago with developed reproductive structures. Adults only live for a few days. Leptophlebiidae species are univoltine or bivoltine but may have multiple cohorts present at one time. Adults of some species emerge intermittently throughout the year with a poorly synchronised life cycle while for other species adult emergence is confined to a period of 3 months, usually in summer.

    leptophlebiid mayfly with pupal midge parasite



    immature without wing pads 

    Key Note: Specimens without wing pads are early instars and cannot be confidently identified at genus level.

    Information Sources: Dean 1999a, Dean 2011, Peters & Campbell 1991, Gooderham & Tsyrlin 2002, Dean 2000a, Dean & Suter 1996, 2004, Merritt & Cummins 1996, Elliott et al. 1988, Christidis & Dean 2005
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