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

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Largely because of the venation, the family has been regarded as one of the most primitive ditrysian groups. However, the chaetotaxy of the larvae, male genitalia and general biology and appearance suggest a close relationship with the Tortricidae. It is possible that the Cossidae and Tortricidae are among the earliest branches of the ditrysian lineage with tortricoid S2 apodemes (termed the Apoditrysia by Minet (1983)).


Wood moths, goat moths; small to very large; head with raised, slender scales on vertex and often a tuft of converging scales on frons; ocelli usually absent; chaetosemata absent; antennae usually bipectinate, rarely lamellate or filiform in male, usually filiform or weakly pectinate in female; proboscis very short, naked or absent; maxillary palps minute, 1- or 2-segmented; labial palps short and straight or moderate and upturned; epiphysis rarely absent; spurs 0-2-4, 0-2-2 or absent. Fore wing elongate, strong, pterostigma rarely present, retinaculum on Sc or between costa and Sc, female frenulum of 2-30 bristles, females of some species brachypterous, with strong forked M in cell, chorda usually present, R 3 usually stalked with R 4 (and R 5 ) to termen, CuP present; hind wing broad, M usually forked in cell, with 3 A veins, CuP sometimes reduced. Eggs of flat type in Zeuzerinae, upright with ribs in most Cossinae. Larva stout, prothorax with large dorsal, sclerotised, shield and 3 L setae; crochets usually in an ellipse, uni-, bi- or triordinal, wood-boring. Pupa long, cylindrical and well sclerotised, head usually with spine; abdominal segments 3-7 movable in male, 3-6 in female, T2-7 in males and 2-6 in females each with 2 transverse rows of spines, T8 in male, T7 and 8 in female each with one row; cremaster absent; protruded from tunnel at ecdysis.


Australia has a rich and diverse cossid fauna (Turner 1945; Tindale 1953). Females lay their eggs singly, in pairs or in large numbers, inserting them into crevices, or depositing them on the food plant. The larvae bore in the heartwood or in the larger roots of living trees, shrubs or woody herbs, form galleries beneath bark, or rarely tunnel in soil, feeding externally on roots. Pupation occurs in a chamber within the tunnel.

Cossidae images on Australian Moths Online

  • Endoxyla mackeri

  • Pupa of a Cossidae sp

  • Larva of Endoxyla leucomachla