Oecetis, McLachlan, 1877

Wells, Alice, 2006, A review of Australian long-horned caddisflies in the Oecetis pechana-group (Trichoptera: Leptoceridae), with descriptions of thirteen new species, Memoirs of Museum Victoria 63 (2), pp. 107-128 : 109

Key to males of the Oecetis pechana- species group in Australia

[excluding O. lurida for which males are not associated]

1. Forewing with 1 or more patches of scales (androconia) on lamina (figs 1, 6) 2

— Forewing without scales on lamina (figs 38, 39) 17

2. Inferior appendages in ventral view with length less than twice width at base (figs 13, 31) 3

— Inferior appendages in ventral view with length about twice width at base, or longer (figs 3, 7, 17), 4

3. Inferior appendages in ventral view more or less quadrate; phallus in lateral view with paramere about 2–3 times length of abdominal segment VIII, strongly arched dorsally (figs 31, 32) O. jenniae

— Inferior appendages in ventral view more or less quadrate; phallus about 3–4 times length of abdominal segment VIII, almost straight (figs 13, 15) suteri

4. Inferior appendages in ventral view abruptly angled meso-dorsally at about two-thirds length, rather than smoothly curved, apices truncate (fig. 25) O. geniculata

— Inferior appendages not as above 5

5. Pre-anal appendages with length about 3 times width (figs 52, 53) O. ada

— Pre-anal appendages with length less than 3 times width (figs 34,36,44,45) 6

6. Inferior appendages in ventral view with a triangular meso-basal lobe dorsally (figs 33, 35) 7

— Inferior appendages without a lobe as above 8

7. Inferior appendages in ventral view with the triangular meso-basal dorsal lobe prominent and proximal to a sharply triangular apico-mesial angle (fig. 35) O. theischingeri Inferior appendages in ventral view with the triangular meso-basal dorsal lobe less prominent and without a sharply triangular apico-mesial angle (fig. 33) O. mouldsi

8. Inferior appendages in ventral view with length more than 3 times basal width; phallus short, about length of 1 abdominal segment, sclerotised paramere slender (figs 43, 45) O. buitenzorgensis

— Not as above 9

9. Inferior appendages in ventral view fused mesially in basal third; in lateral view with length about 4 times width (figs 49, 50) O. searica

— Not as above 10

10. Inferior appendages in ventral view stout, mesial margin excavated in distal half; phallus greater than 4 times length of abdominal segment VIII (fig. 3) O. pechana

— Not as above 11

11. Inferior appendages in ventral view stout at base, gradually excavated towards apex, slender distally; phallus in lateral view with sclerotised paramere arched ventrally (figs 22– 24) O. kateae

— Not as above 12

12. Inferior appendages in ventral view stout throughout length, mesially gradually excavated from base, apices rounded (figs 7, 54) 13

— Not as above 15

13. Phallus with sclerotised paramere equal to about 2–3 times length of abdominal segment VIII 14 Phallus without sclerotised paramere (fig. 54) O. gilva (part)

14. Inferior appendages in ventral view dilated lateral at about half length, somewhat sinuous in appearance (fig. 7) O. walpolica

— Inferior appendages in ventral view swollen basally, gradually tapered towards apices ( Neboiss, 1977: fig. 771) O. umbra

15. Inferior appendages in ventral view stout basally, sharply excavated on mesial margin at about two-thirds length, apices rounded; sclerotised paramere of phallus about length of 2 abdominal segments (figs 9, 10) O. magelensis

— Not as above 16

16. Inferior appendages about equal width throughout length, sinuous in lateral view, apices rounded to truncate (figs 16, 17) O. radonensis Inferior appendages about equal width for most of length, distally tapered to acute convergent apices (figs 19, 20) O. humphreyi

17. Forewing with distinctly spotty pattern; inferior appendages close-pressed meso-ventrally for proximal half, mesial margin excavated in distal half; phallus about length of 2 abdominal segments, with sclerotised paramere strongly arched dorsally, down-turned in distal section, apically acute (figs 27, 28) O. litua

— Forewing without distinctly spotty pattern, although usually with crossveins and vein forks and anastomoses marked by dark membrane and hair; inferior appendages not close-pressed for more than one-fifth length; phallus usually shorter than length of 2 abdominal segments, sclerotised paramere strongly reduced, absent or very slender 18

18. Inferior appendages with length longer than basal width (fig. 54) O. gilva (part)

— Inferior appendages with basal width greater than length (figs 37,40,46) 19

19. Inferior appendages in ventral view with apico-mesial angles acute; phallus with sclerotised paramere finely whip-like distally; a pair of membranous lobes flanking abdominal segment X (fig. 37) O. australis

— Not as above 20

20. Abdominal segment X in lateral view with an apically acute ventral process at about half length; inferior appendages in lateral view tapered toward apex (figs 40, 42); antennal segment with brush of long setae on leading edges O. quadrula

— Abdominal segment X in lateral view expanded towards apex, lacking a ventral process; inferior appendages in lateral view rod-shaped (fig. 48); each antennal segment with setae all about equal length O. burtoni