Definition of alderfly in US English:


(also alder fly)


  • A brownish insect that lives near water and has predatory aquatic larvae.

    Family Sialidae, order Neuroptera: several genera

    • ‘Most alderfly investigations have been in the temperate regions of North America and Europe.’
    • ‘The alderfly pupa isn't available to fish, as the larva crawls out of the water onto shore before pupating.’
    • ‘Larvae of alderflies differ from hellgrammites in that they lack the two hooks at the end of the abdomen.’
    • ‘This is a very small order of Australian insects commonly known as alderflies and dobsonflies.’
    • ‘The alderfly larvae, known to all and coveted by fish and anglers alike, is the hellgrammite.’