Oecetis laustra, Mosely, 1953

Wells, Alice, 2004, The long-horned caddisfly genus Oecetis (Trichoptera: Leptoceridae) in Australia: two new species groups and 17 new species, Memoirs of Museum Victoria 61 (1), pp. 85-110 : 87-89

Key to males of the Oecetis laustra -group in Australia

1. Forewing with distinct footstalk on fork 1 (Fig. 1).... 2

— Forewing with fork 1 sessile ( Figs 80 , 87, 88), or very nearly so.................................. 25

2. In hind wing, M unbranched (Fig. 73); in male genitalia in lateral view, inferior appendages about same width basally and apically, constricted mesially (Fig. 72)... O. papposa

— In hind wing, M branched; male genitalia not as above.3

3. In hind wing, Cu1 and Cu2 arise at crossvein M-Cu (Fig. 53)........................... O. quadrata

— In hind wing, Cu1 and Cu2 arise distal to crossvein M-Cu ........................................... 4

4. In forewing, at least 2 crossveins contiguous (linear), or nearly so, in posterior anastomosis (Figs 10, 12)..... 5

— In forewing, crossveins of posterior anastomosis all clearly stepped (Figs 29, 30)................... 13

5. Forewing with distinctive dark lines marking parts of veins, including diagonal mark linking t1, t2, t3 (Fig. 12)................................... O. inscripta

— Forewing not as above......................... 6

6. In genitalia, inferior appendages in lateral view swollen basally, distally reduced to at least one-third basal width and strongly curved dorsad..................... 7

— In genitalia, inferior appendages in lateral view not as above (Figs 18, 39).......................... 10

7 In genitalia, in ventral view, inferior appendages tapered gradually towards apex, mesial margin slightly dentate or with a single sharp mesial hook (Fig. 2)............ 8

— In genitalia, in ventral view, inferior appendages sharply excavated at about one-third length, distally slender, mesial margin smooth (Figs 8, 26)................ 9

8. In genitalia, in ventral view, inferior appendages with a small mesial tooth (Fig. 2)............... O. laustra

— In genitalia, in ventral view, inferior appendages with a sharp anteriorly directed mesial hook (Fig. 4)....................................... O. pseudolaustra

9 Forewing with dark membrane marking posterior anastomosis; genitalia in lateral view with peg-like process ventral to preanal appendages (Fig. 9)...... O. atarpa

— Forewing without dark markings at posterior anastomosis (Fig.10); without peg-like process ventral to preanal appendages ( Fig. 11 )................. O. scirpicula

10. In forewing t3 well proximal to t1 and t2, with M3+4 arising distal to t3; wing lamina patterned with dark marking on crossveins t1, t2 and M forming a short dark distal cross (Fig. 15).................... O. brevidentata

— In forewing t3 only slightly proximal to t1 and t2, with M3+4 arising at t3; wing lamina mottled, without distinct marking................................... 11

11. In genitalia in ventral view, inferior appendages broad in basal two-thirds, mesial margin rounded then abruptly constricted, curved inwards towards apices, not sharply angled (Fig. 19); tergite X slim, digitiform...... O. asmanista

— In genitalia in ventral view, inferior appendages broad-based with meso-ventral angle slightly lobed, mesial margin strongly constricted to form a narrow lobe laterodistally, with apex sharply angled inwards (Figs 21, 24); tergite X a broad membrane.................... 12

12. In genitalia in ventral view, phallus with apex sharply delineated and deeply V-shaped (Fig. 24).. O. erskinensis

— In genitalia in ventral view, phallus with apex rounded, very shallowly cleft (Fig. 21)............ O. minasata

13. In forewing, t1 more distal than t2 or t3 (Figs 64, 73).14

— In forewing, t2 more distal than t1 or t3 (Fig. 30)....17

14. Male genitalia with prominent, unequal sclerotised spines dorsally (Figs 65–67)................... O. falcata

— Male genitalia without any sclerotised spines (Figs 60, 62) .......................................... 15

15. Forewing fork 1 and its footstalk about equal length; on forewing a zig-zag pattern marks posterior anastomosis (Fig. 63)........................... O. koobarra

— Forewing fork 1 longer than its footstalk; forewing posterior anastomosis not marked by zig-zag pattern. 16

16. Male genitalia, in ventral view, with inferior appendages stout throughout length, about 1.5 times width, rounded mesially, apically a small curved lateral process (Fig. 57); tergite X broad, apically truncate (Figs 58, 59)...................................... O. dilata

— Male genitalia, in ventral view, with inferior appendages stout basally, gradually constricted to about half basal width; tergite X excavated mesially to form a pair of apically acute lateral processes (Figs 47, 48)................................... O. spicata (N Qld form)

17. Male genitalia, in lateral view, with a small digitate lobe dorsal to base of inferior appendages (Fig. 38). O. parka

— Male genitalia, in lateral view, without a small lobe as above..................................... 18

18. Male genitalia, in ventral view, with a lobe on mesial side of inferior appendages (Fig. 69)........... O. terania

— Male genitalia, in ventral view, without a lobe as above.19

19. Wings uniformly fuscous, vestiture short, dense; in male genitalia, tergite X comprising a median, tapered lobe between a pair of broadly rounded, membranous lateral lobes (Figs 42, 45)........................... 20

— Wings mottled or with some small markings, or spotted; tergite X not as above........................ 21

20. Male genitalia, in lateral view, with inferior appendages about same width throughout length, apices not down-turned (Fig. 43)....................... O. cymula

— In genitalia, in lateral view, inferior appendages dilated baso-ventrally, apices down-turned, rounded (Fig. 46).................................... O. paracymula

21. In genitalia, in ventral view, inferior appendages broad-based, abruptly narrowed, expanded slightly mesially, distally about width of narrower basal section (Fig. 50); in lateral view, inferior appendages with a broadly rounded basodorsal lobe, distally tapered, slender (Fig. 52).......................................... O. crena

— In genitalia, in ventral view, inferior appendages not as above..................................... 22

22 In genitalia, in lateral view, inferior appendages truncate apically, in distal half about half width at base (Fig. 40); in ventral view, a distinct notch on mesial margin at about two-thirds length (Fig. 39)............... O. arcada

— Not as above............................... 23

23. In genitalia, inferior appendages in lateral view expanded dorsally, narrow in distal two-thirds (Fig. 36); in ventral view gently curved inwards and tapered to acuminate apices (Fig. 34)...................... O. cracenta

— Not as above............................... 24

24. In genitalia, in ventral view, inferior appendages stout basally gradually curved and constricted to narrowly rounded apex; preanal appendages rounded (Figs 31–33)................................ O. multipunctata

— In genitalia, in ventral view, inferior appendages stout at base, abruptly narrowed to form slender disto-lateral lobes; preanal appendages in dorsal view triangular, in lateral view slender, tapered (Figs 26–28)...... O. aeoloptera

25. Forewing distinctly and coarsely patterned, dark brown and fuscous ( Fig. 80 )................... O. ornata

— Forewing not as above, but may be spotted, moth-like 26

26. Male genitalia with, tergite X hairy, rounded, cleft medially (Fig. 75)....................... O. curta

— Tergite X not as above........................ 27

27. In genitalia, tergite X membranous with apicolateral angles acute (Fig. 48)............... O. spicata (NT form)

— In genitalia, tergite X not as above............... 28

28. Wings not spotted; in genitalia, in lateral view, preanal appendages narrow, length 2x width (Figs 78, 79)........................................ O. aduncata

— Wings spotted (Figs 87, 88); in genitalia, in lateral view, preanal appendages broadly rounded or subtriangular (Figs 86,89) .................................... 29

29. In genitalia, tergite X in dorsal view minaret-shaped (Fig. 85); inferior appendages in ventral view with tiny hook at mesial angle....................... O. cepaforma

— Male genitalia with, tergite X in dorsal view broad, apically truncate (Fig. 90); inferior appendages in ventral view without tiny hook at mesial angle............................................ O. dostinei

Figures

Figure 11, Oecetis scirpicula Neboiss, male genitalia, lateral view [from Neboiss, 1977]. Figures 12–14, O. inscripta Kimmins: 12, forewing; 13, 14, male inferior appendages in ventral view, genitalia in lateral view [from Mosely and Kimmins, 1953]. Figures 15–18, O. brevidentata sp. nov.: 15, forewing; 16–18, male genitalia, ventral, dorsal and lateral views. Figure 19, 20, O. asmanista Mosely, male genitalia, ventral and lateral views [from Mosely and Kimmins, 1953].

Figures 80, O. ornata Kimmins, forewing (drawn from Australian specimen). Figures 81–83, Oecetis ornata Kimmins: 79–81, male genitalia, ventral, dorsal and lateral views (drawn from Australian specimen). Figures 84–87, O. cepaforma sp. nov.: 84–86, male genitalia, ventral, dorsal and lateral views; 87, forewing. Figures 88–90, O. dostinei sp. nov.: 88, forewing; 89, 90, male genitalia, ventral, dorsal and lateral views.