Adults

1.  
   • Insects small, usually 5 mm or less in length; antennae shorter than fore wing; maxillary palps 5-segmented in both sexes; scutellum flat, triangular, pointed posteriorly, margins vertical (Fig. 40.5C); mesoscutum without setal warts; wings narrow, pointed apically (Fig. 40.7D), fringes very long, those of hind wing usually longer than width of the wing Hydroptilidae
   • Insects usually more than 5 mm long; antennal length variable, up to 3 times the length of fore wing; maxillary palps 1--6 segmented in [Zm][Zm], 5- or 6-segmented in [Zf][Zf]; scutellum broad posteriorly, convex, without vertical margins (Fig. 40.5B); mesoscutum frequently with setal warts; wings proportionally broad, fringes usually short, less than width of wing 2
2. (1)
   • Ocelli present (Fig. 40.5A) 3
   • Ocelli absent (Fig. 40.5F) 7
3. (2)
   • Maxillary palps with segment 5 flexible or annulate, distinctly longer than segment 4 (Fig. 40.7I) Philopotamidae
   • Maxillary palps 3- or 5-segmented, apical segment not flexible or annulate, about same length or shorter than preceding segment 4
4. (3)
   • Maxillary palps 5-segmented in both sexes, segments 1 and 2 short, stout; without setal warts on mesoscutum 5
   • palps 3-segmented in [Zm][Zm], 5-segmented in [Zf][Zf]; segment 1 short, cylindrical; segment 2 usually longer than segment 1, mesoscutum with setal warts or 2 parallel bands of setose punctures 6
5. (4)
   • Segment 2 of maxillary palps with globular, mesally directed, lateral projection (Fig. 40.7G) Glossosomatidae
   • Segment 2 of maxillary palps cylindrical, without lateral projection Hydrobiosidae
6. (4)
   • Mesoscutum with one pair of elongate setal warts (Australian species only) (Fig. 40.5L) Limnephilidae
   • Mesoscutum with 2 parallel bands of setose punctures mesally and 2 small groups posteriorly, either side of scutellum (Fig. 40.5N) Plectrotarsidae
7. (2)
   • Maxillary palps 5-segmented in both sexes; apical segment flexible, annulate, at least twice as long as segment 4 (Fig. 40.7L) 8
   • Maxillary palps 1- to 6-segmented in [Zm][Zm], 5- or 6-segmented in [Zf][Zf]; apical segment generally short, not flexible, apical one or 2 segments sometimes granular in texture, but not annulate (Fig. 40.10I) 11
8. (7)
   • Mesoscutum without setal warts (Figs 40.5F, G) Hydropsychidae
   • Mesoscutum with setal warts (Fig. 40.5H) 9
9. (8
   • Fore wing vein R1 forked at apex (sometimes difficult to see) (Fig. 40.8F) Ecnomidae
   • Fore wing vein R1 not forked at apex 10
10. (9)
    • Mesoscutal warts separated by anterior extension of scutellum (Fig. 40.5E) Stenopsychidae
    • Mesoscutal warts not separated by anterior scutellar extension (Fig. 40.5H) Polycentropodidae
11. (7)
    • Mid tibia with preapical spurs 12
    • Mid tibia without preapical spurs 18
12. (11)
    • Maxillary palp segment 1 short, expanded apicomesally and bearing a tuft of setae (Fig. 40.10E) Philorheithridae
    • Maxillary palp segment 1 elongate, without apicomesal expansion 13
13. (12)
    • Mesoscutum with one pair of setal warts 14
    • Mesoscutum without setal warts, but with 2 longitudinal bands or groups of setiferous punctures 16
14. (12)
    • In fore and hind wings R1 joins R2 before wing margin (Fig. 40.8J); maxillary palps of [Zm] 1- or 2-segmented (in Australian genus Tascuna 1-segmented) Oeconesidae
    • In fore and hind wings R1 reaches wing margin separately from R2; maxillary palps of [Zm] 3- or 4-segmented 15
15. (14)
    • Head with mouth-parts slightly to considerably extended; fore wing vein R1 joins Sc basad of pterostigma by short cross-vein or sharp bend; discoidal cell closed (Fig. 40.9A); maxillary palpi of [Zm] 3-segmented Kokiriidae
    • Head with mouth-parts normal, not extended; fore wing vein R1 without sharp bend, not joined to Sc by cross-vein; discoidal cell open (Fig. 40.8I); maxillary palps of [Zm] 4-segmented Tasimiidae
16. (13)
    • Fore wing median cell closed (Fig. 40.10G); maxillary palps 6-segmented in both sexes; spurs 2:4:3 (genus Anisocentropus) Calamoceratidae
    • Fore wing median cell open or absent; maxillary palps 5-segmented in both sexes; spurs 2:4:4 17
17. (16)
    • Fore wing veins R1 and R2 join shortly before wing margin (Fig. 40.10J) Odontoceridae
    • Fore wing veins R1 and R2 run separately to wing margin (Fig. 40.10H) Atriplectididae
18. (11)
    • Mesoscutum with one pair of setal warts (Fig. 40.6F), sometimes indistinct 19
    • Mesoscutum without setal warts, but may have 2 parallel bands of setose punctures 20
19. (18)
    • Fore wing rounded apically, discoidal cell closed; scutellum with pair of warts, sometimes fused mesally; at least first few abdominal sternites with reticulate pattern Helicopsychidae
    • Fore wing acute apically, discoidal cell open; scutellum with one, mesal, dome-shaped setal wart (Fig. 40.5R); abdominal sterna without reticulate pattern Antipodoeciidae
20. (18)
    • Mesoscutum without bands of setose punctures; setae, if present, minute and scattered 21
    • Mesoscutum with pair of irregular bands of setose punctures, extending for part or entire length of mesoscutum 23
21. (20)
    • Wing coupling by hamuli on basal section of costal margin of hind wing, distal hamuli more closely grouped; jugal lobe reduced; hind wing with large, vein-free area discally (Fig. 40.9D) Helicophidae
    • Wing coupling by enlarged hairs along costal margin of hind wing, hairs at most only slightly curved; jugal lobe well developed; hind wing discal area without vein-free area (Fig. 40.9E) 22
22. (21)
    • Pronotum with 2 pairs of setal warts, mesal pair small, rounded, lateral pair oval (Fig. 40.5P) (except [Zm] of Caenota, where only one elongate pair is present, but then hind wing vein R1 joins Sc for short distance before ending separately at wing margin (Fig. 40.9I)); fore wing without hyaline spot at arculus Calocidae
    • Pronotum with pair of elongate setal warts (Fig. 40.5T); fore wing usually with hyaline spot near arculus (Fig. 40.9E); hind wing vein R1 usually runs free to wing margin, rarely Sc joins R1 near margin Conoesucidae
23. (20)
    • Antennae stout, about as long as fore wing (longer in brachypterous species); scutellum with pair of indistinctly fused warts; maxillary palps stout, 5-segmented in both sexes, segment 2 lengthened, produced beyond insertion of segment 3 in [Zm] (Fig. 40.8H) Chathamiidae
    • Antennae filiform, slender, 2–3 times as long as fore wing; scutellum without warts but may have few setiferous punctures; maxillary palps slender, 5-segmented and similar in both sexes, segment 2 unmodified (Fig. 40.10L) Leptoceridae

LARVAE

Kokiriidae and Oeconesidae are included in the key on the basis of unidentified larvae agreeing with family descriptions presented by Cowley (1978) based on confirmed New Zealand larvae. Stenopsychidae are omitted; a larva which may belong to this family keys to Polycentropodidae.

1.  
   • First abdominal segment of larvae with dorsal and/or lateral protuberances, lateral protuberances usually with small sclerites or a pad-like surface bearing spines, spicules or setae; anal claws lateral on apparent 10th abdominal segment formed by fusion of abdominal prolegs; constructing portable cases. Superfamily LIMNEPHILOIDEA 8
   • First abdominal segment of larvae without protuberances or lateral pad-like surfaces; anal claws terminal on well developed abdominal prolegs (except Hydroptilidae); free-living (Hydrobiosidae and early instar Hydroptilidae), living in fixed retreats (Hydropsychoidea) or constructing portable cases (Glossosomatidae and Hydroptilidae). Superfamilies RHYACOPHILOIDEA and HYDROPSYCHOIDEA. 2
2. (1)
   • Dorsal sclerotisation on first thoracic segment only 3
   • Dorsal sclerotisation on all three thoracic segments, although incomplete on meso- and metanota in some families 5
3. (2)
   • Labrum membranous, anterior margin considerably broader than posterior margin (Fig. 40.11P) Philopotamidae
   • Labrum sclerotised, anterior margin not broader than posterior margin 4
4. (3)
   • Fore trochantin distinct and well developed; fore leg not modified (Fig. 40.12L) Polycentropodidae
   • Fore trochantin reduced, not at all obvious; fore leg modified, either chelate (Fig. 40.11F) or with femur broadened and bearing a field of stout spines (Fig. 40.11E) Hydrobiosidae
5. (2)
   • Meso- and metanota each bearing a pair of small sclerites (Fig. 40.11K); constructing dome-shaped portable stone case Glossosomatidae
   • Meso- and metanota with sclerotisation complete or almost complete; not constructing stone cases 6
6. (5)
   • Abdominal gills present (Figs 40.12A, F) Hydropsychidae
   • Abdominal gills absent 7
7. (6)
   • Abdomen of final instar larva swollen, much broader and deeper than head and thorax (Figs 40.11L, M); abdominal prolegs not well developed; final instar larva portable purse-shaped case maker Hydroptilidae
   • Abdomen not swollen, only slightly broader and deeper than head and thorax; abdominal prolegs well developed; living in fixed retreats (Fig. 40.12O) Ecnomidae
8. (1
   • Larvae constructing helical case of sand grains (Fig. 40.14L); anal claw with comb-like structure (Fig. 40.14M) Helicopsychidae
   • Larvae not constructing helical case of sand grains; anal claw with dorsal accessory hook simple or absent 9
9. (8)
   • Head comparatively small, narrow, without visible ecdysial lines (Fig. 40.14A); pronotum with 2 pairs of sclerites on anterior half, posterior half membranous and retractable into mesonotum Atriplectididae
   • Head not reduced, ecdysial lines distinct; pronotum completely sclerotised, not retractable into mesonotum 10
10. (9)
    • Mid leg with tibia and tarsus fused 11
    • Mid leg with tibia and tarsus not fused 12
11. (10)
    • Tibia and tarsus fused in fore leg (Figs 40.13F, G); ventral apotome of head capsule extending to occipital foramen, completely separating genae Kokiriidae
    • Tibia and tarsus not fused in fore leg (Fig. 40.14.I); ventral apotome of head capsule short, not reaching to occipital foramen (Fig. 40.14G) Philorheithridae
12. (10)
    • Prosternum with median horn-shaped process 13
    • Prosternum without median horn-shaped process 14
13. (12)
    • Venter of 1st abdominal segment with 3 pairs of setae Plectrotarsidae
    • Venter of 1st abdominal segment with numerous setae Limnephilidae
14. (12)
    • Metasternum with 2 or more setae 15
    • Metasternum without setae 16
15. (14)
    • Femur of hind leg divided into short proximal and longer distal sections (Fig. 40.4F); antennae obvious, relatively long, usually longer than 1/5 the width of anterior margin of frontoclypeal apotome, located close to frontal edge of head capsule (Fig. 40.14V) (except in Triplexa, antennae minute, about half way between eye and base of mandible); freshwater, some in brackish waters (Symphitoneuria) Leptoceridae
    • Femur of hind leg not divided into 2 sections; antennae short, less than 1/5 the width of anterior margin of frontoclypeal apotome, located halfway between eyes and frontal edge of head capsule (Fig. 40.12T); marine intertidal Chathamiidae
16. (14)
    • Abdominal segments with lateral fringe of fine filaments 17
    • Abdominal segments without lateral fringe 19
17. (16)
    • Head capsule with prominent carina (Fig. 40.13M) Oeconesidae
    • Head capsule without carina 18
18. (17)
    • Eyes bulging, contained in semi-circular dorsal protuberances of the head capsule (Fig. 40.13.A); venter of 1st abdominal segment bearing setae; case constructed of small stones Tasimiidae
    • Eyes not bulging (Fig. 40.14P); venter of 1st abdominal segment without setae; case constructed of 2 ovate pieces of leaf, dorsal piece larger than ventral Calamoceratidae
19. (16)
    • Prosternum with large sclerite(s) Odontoceridae
    • Prosternum membranous 20
20. (19)
    • Ventral surface of head capsule with genae widely separated at occipital foramen (Fig. 40.13R) Conoesucidae
    • Ventral surface of head capsule with genae close together and almost abutting at occipital foramen (Figs 40.13T, X) 21
21. (20)
    • Strong carina extending obliquely across pronotum, terminating in a pointed and dorsoventrally flattened projection at each anterolateral corner (Fig. 40.13V) Antipodoeciidae
    • Carina absent or, if present, parallel to lateral margin of pronotum, not terminating in a projection at each antero-lateral corner 22
22. (21)
    • Antennae situated very close to eyes (Fig. 40.13W) Calocidae
    • Antennae situated about halfway between eyes and frontal edge of head capsule (Fig. 40.14D) Helicophidae

*Note

Interactive keys to Trichoptera are currently not available. Dichotomous ones 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.