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

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Identify families


    • Antennae more than 20-segmented, never secondarily annulated; tarsi 3-segmented; pterostigma not thickened, or absent; paraprocts with strong posterior spine TROGIOMORPHA
    • Antennae usually 13-segmented, if 12- or 15–17-segmented, some segments are secondarily annulated; tarsi 2- or 3-segmented; pterostigma thickened or not; paraprocts without strong posterior spine 2
  2. (1)
    • Antennae 12- or 15–-17-segmented, some segments secondarily annulated; tarsi 3-segmented; pterostigma not thickened TROCTOMORPHA
    • Antennae usually 13-segmented; tarsi 2- or 3-segmented, if latter then flagellar segments not secondarily annulated; pterostigma thickened PSOCOMORPHA



    • Head long and vertical; maxillary palp without sensillum on 2nd segment; CuP and 1A end together at wing margin (nodulus) PSOCATHROPETAE. Psyllipsocidae
    • Head short; inner side of 2nd segment of maxillary palp with sensillum; in winged forms CuP and 1A end separately at wing margin ATROPETAE. 2
  2. (1)
    • Claws with preapical tooth; body and wings usually scaly; if scales absent fore wings are acuminate Lepidopsocidae
    • Claws toothed; body and wings never scaly; fore wings rounded or absent 3
  3. (2)
    • Fore wings well developed or shortened but always with veins; hind wings usually reduced Psoquillidae
    • Fore wings present only as veinless flaps, or absent; hind wings absent Trogiidae



  2. (1)
    • Wings, when present, with complete venation. (In both alate and apterous forms eyes seated near vertex; thoracic sterna narrow, without cilia; hind femora not basally widened) Pachytroctidae
    • Wings, when present, with incomplete venation, lacking terminal branches. (In all apterous forms meso- and metathorax indistinguishably fused) 3
  3. (2)
    • In alate forms both fore and hind wings present; eyes near vertex. In apterous forms eyes remote from vertex, each consisting of 2 large elements alone or preceded by 6 or fewer small ocelloids. Pronotum lobed; thoracic sterna broad and bearing cilia; hind femora broad basally Liposcelidae
    • In alate forms only fore wings present, convex, elytriform. In all forms eyes remote from vertex, composed of few ocelloids, none greatly enlarged; pronotum simple; thoracic sterna narrow, without cilia; hind femora not widened basally Sphaeropsocidae


    • Adults macropterous 2
    • Adults brachypterous or apterous 25
  2. (1)
    • Labrum with 2 narrow, sclerotised bands or ridges from base to distal margin Epipsocidae
    • Labrum without such bands or ridges 3
  3. (2)
    • Tarsi 3-segmented 4
    • Tarsi 2-segmented 10
  4. (3)
    • Fore wings glabrous 5
    • Fore wings with at least a few setae on veins and/or margin 8
  5. (4)
    • Areola postica free 7
    • CuA1 fused with M for a length 6
  6. (5)
    • Wing pattern of dense spots and blotches Myopsocidae
    • Wing pattern of bold dark and light areas Elipsocidae (pt.)
  7. (5)
    • Areola postica shallow, extending well basal to junction of CuA2 and wing margin; fore wing with cloudy pattern Psilopsocidae
    • Areola postica tall, arched not extending basal to junction of CuA2 and wing margin; fore wing hyaline except for pterostigma Mesopsocidae (pt.)
  8. (4)
    • Tarsal claws without preapical tooth Pseudocaeciliidae (pt.)
    • Tarsal claws with preapical tooth 9
  9. (8)
    • Hind wing with marginal setae only between R2+3 and R4+5 Elipsocidae (pt.)
    • Hind wing with marginal setae along most of margin and posterior to R2+3 Philotarsidae (pt.)
  10. (3)
    • Fore wing venation indistinct Archipsocidae (pt.)
    • Fore wing venation distinct 11
  11. (10)
    • Areola postica present 13
    • Areola postica absent 12
  12. (11)
    • Pterostigma more or less rectangular. Hind wing with Rs and M usually joined by a cross-vein (fused only in Interpsocus) Ectopsocidae (pt.)
    • Pterostigma with clearly sinuous hind margin. Hind wing with Rs and M fused for a length Peripsocidae (pt.)
  13. (11)
    • Fore wing with at least a few setae on veins and/or margin 15
    • Fore wings glabrous 14
  14. (13)
  15. (13)
    • M 2-branched in fore wing 16
    • M 3-branched in fore wing 18
  16. (15)
    • Areola postica joined to M by a cross-vein Hemipsocidae
    • Areola postica free 17
  17. (16)
  18. (15)
    • Areola postica joined to M 19
    • Areola postica free 21
  19. (18)
    • Network of veins at least behind pterostigma, frequently more extensive Calopsocidae (pt.)
    • No network of veins behind pterostigma 20
  20. (19)
    • Pterostigma long and narrow Amphipsocidae
    • Pterostigma with distinct widening in distal half Psocidae (pt.)
  21. (19)
    • Single row of setae on veins of fore wings 23
    • Setae on veins of fore wing in two rows 22
  22. (21)
  23. (21)
    • Cross-vein between pterostigma and Rs Stenopsocidae
    • No cross-vein between pterostigma and Rs 24
  24. (23)
    • Hind wing with apical and/or posterior marginal setae alternately longer and shorter Trichopsocidae
    • Hind wing with apical and/or posterior marginal setae all of similar length Caeciliidae (pt.)
  25. (2)
    • Tarsi 3-segmented 26
    • Tarsi 2-segmented 28
  26. (25)
    • Reduced wings with at least some setae present 27
    • Reduced wings with indistinct venation, glabrous Mesopsocidae (pt.)
  27. (26)
    • Setae on fore wing veins arising from dark spots Philotarsidae (pt.)
    • Setae on fore wing veins not arising from dark spots Elipsocidae (pt.)
  28. (25)
    • Brachypterous 30
    • Apterous 29
  29. (28)
    • Head and body with glandular setae; claws with preapical tooth Elipsocidae (pt.)
    • Head and body without glandular setae; claws without preapical tooth Archipsocidae (pt.)
  30. (28)
    • Claws without preapical tooth 31
    • Claws with preapical tooth 32
  31. (30)
  32. (30)


Interactive keys to Psocoptera are currently unavailable. Dichotomous keys from The Insects of Australia (Second Edition, 1991) have been provided until interactive ones are ready. These keys are presented as they originally appeared; no attempt to update them or the classification has been made.