Key to the genera and species of Australian Ploiariolini

1. Basal portion of discal cell of forewing truncate with two longitudinal veins emitted from its base (M and Cu), these veins may (Fig.5 B) or may not (Fig. 4 A) form a triangular subbasal cell.................................................. 6

- Basal portion of discal cell of forewing attenuate, M and Cu fused forming a single longitudinal vein emitted from its base (Figs. 1 A, B; 14A; 15).................................................................................. 2

2. Pterostigma well-developed, virtually reaching wingtip (Figs. 1 A, B); carinae on lateral portion of posterior lobe of pronotum absent (Fig. 1 D); wool-like pile absent from head and pronotum ( Ademula).......................... Ademula austrina

- Pterostigma less developed, barely surpassing the apical portion of the discal cell (Fig. 12 A); carinae on lateral portion of posterior lobe of pronotum present (Figs. 12 C; 14C; 16B; 17C); wool-like pile present on head and pronotum ( Empicoris).... 3

3. Lateral carinae of pronotum forming an uninterrupted ridge between the humeral angles and the anterior extremities of the hind lobe (Figs. 12 C; 14C)............................................................................. 4

- Lateral carinae of pronotum incomplete, restricted to the anterior extremities of the hind lobe (Fig. 16 B)................................................................................................ Empicoris rubromaculatus

4. Discal cell of forewing relatively elongate, 3.5– 4 X longer than wide (Fig. 12 A); anteocular and postocular regions of head subequal in length (Fig. 12 C); parameres strongly elliptical prior to apex.......................... Empicoris aeneus n. sp.

- Discal cell of forewing relatively stout, 2–2.5X longer than wide (Figs. 14 A; 17A); anteocular region of head shorter than postocular (Figs. 14 C; 17C); parameres roughly parallel-sided prior to apex (Fig. 17 F)................................. 5

5. Forecoxae almost entirely chestnut-coloured (Fig. 14 D); macrochaetae of abdomen interspersed amongst an evenly spaced blanket of microchaetae (Fig. 14 G); posterior margin of pygophore as in Figure. 14 E......... Empicoris gradapallida n. sp.

- Forecoxae almost entirely white (Fig. 17 D), macrochaetae of abdomen surrounded by large microchaetae-free circles, giving the abdomen a scaly appearance (Fig. 17 G); posterior margin of phygophore as in Figure 17 E..................................................................................................... Empicoris scabraventris n. sp.

6. Pterostigma well-developed, virtually reaching wingtip, triangular subbasal cell present (Figs. 21B, D, F); pronotum with faint lateral carinae (Figs. 21A, C, E; Tridemula)................................................................. 7

- Pterostigma less developed, at most barely surpassing the apical portion of the discal cell (Fig. 9); pronotum without lateral carinae (Figs. 4 C; 8B; 11) subbasal cell present (Figs. 5 B) or absent (Figs. 4 A; 7; 9; 10).............................. 9

7. Hind lobe of pronotum with large median tubercle on posterior border (Figs. 21A, E)................................ 8

- Hind lobe of pronotum simple without tubercle (Fig. 21 C), wings as in figure 21D.................. Tridemula metabates

8. Eyes large, approximately equal to 1/2 the length of the head (Fig. 21 E); primarily chestnut-coloured on the lateral portions of posterior lobe of pronotum below the carinae; distal portion of metafemur without annulation; wing as in Figure 21 F.............................................................................................. Tridemula pilosa

- Eyes smaller, approximately 1/3 the length of the head (Fig. 21A); primarily stramineous on the lateral portions of posterior lobe of pronotum below the carinae; distal portion of metafemur with large chestnut-coloured annulation; wing as in Figure 21B ................................................................................ Tridemula contumax

9. Discal cell of forewing with its apical portion truncate, posterior border formed by Cu with double curve (Fig. 19); Mesosepis)....................................................................................... Mesosepis papua

- Discal cell of forewing with its apical portion narrowed (Fig. 7), posterior border formed by Cu with single curve…………. 10

10. Head and thorax covered in dense wool-like pubescence; discal cell often with a small subquadrate basal cell present at the inner proximal angle, this cell sometimes very reduced (Fig. 5 B) or absent (Fig. 9), when basal cell absent the genal portion of head is extremely tumid (Fig 8 B; Emesopsis)............................................................. 11

- Body shining, pubescence sparse, not wool-like; discal cell without a small subquadrate basal cell present at the inner proximal angle (Fig. 4 A); head not abruptly constricted posteroventrally (Fig. 4 C; Calphurniodes)........................... 15

11. M and Cu of forewing united proximally forming a triangular subbasal cell (Fig. 5 B)............................... 12

- M and Cu of forewing not united proximally (Figs. 7; 9)...................................................... 13

12. Forewing with irregular shaped pigmented pattern near apex of discal cell; M vein of subbasal cell sinuate; subbasal cell very narrow, 4.4– 5 X longer than broad (Fig. 5 B).................................................... Emesopsis bunda

- Forewing with distinct dark circular spot near apex of discal cell; M vein of subbasal cell more or less straight; subbasal cell broader, 3.5– 4 X longer than broad (see Wygodzinsky 1966: 359, Fig. 109N)........................ Emesopsis imbellis

13. Membrane of forewing proximal to discal cell between M and Cu entirely filled with brown fenestrated pigment; discal cell with one large central pigmented area (Fig. 7).......................................... Emesopsis fenestrella n. sp.

- Membrane of forewing proximal to discal cell between M and Cu with large pigmentless areas; discal cell with two to many pigmented areas (Figs. 9, 10)........................................................................... 14

14. Basal cell of forewing present, discal cell with distinct transverse pigmentless line dividing main pigmented regions (Fig. 10)................................................................................ Emesopsis monteithi n. sp.

- Basal cell of forewing absent, discal cell without transverse pigmentless line, with many large spots throughout (Fig. 9)...................................................................................... Emesopis infenestra n. sp.

15. Posterior lobe of pronotum stramineous with a broad chestnut-coloured band medially (Fig. 4 C); small (body length ≈ 3.9mm)............................................................................ Calphurnioides insolitus n. sp.

- Posterior lobe of pronotum entirely stramineous without a broad chestnut-coloured band medially (Wygodzinsky 1966: 352, Fig. 106B); larger (body length ≈ 5.2 mm)............................................... Calphurnioides australis