Austroplebeia magna, Dollin, Anne E., Dollin, Leslie J. & Rasmussen, Claus, 2015

Dollin, Anne E., Dollin, Leslie J. & Rasmussen, Claus, 2015, Australian and New Guinean Stingless Bees of the Genus Austroplebeia Moure (Hymenoptera: Apidae) — a revision, Zootaxa 4047 (1), pp. 1-73 : 25

Key to males of the genus Austroplebeia

Remarks. Males of A. australis , A. cassiae and A. magna sp. nov. are very difficult to distinguish in isolation. Their colouration and structural characteristics overlap much more than those of the workers (compare Figs 7 , 8 ). A high quality microscope is needed to see the differences in the mesepisternum plumose hair given in the key. However, these were the most reliable distinctions found between the males of these species in this analysis.

1. Scutellum maculation limited to a very narrow cream band on posterior rim (Thorax Grade 18, Figs 5 , 25 c). Frons and mesepisternum with simple hair ( Figs 23 a, 25c). S6 median body narrow ( Fig. 20 k). Base of penis valve relatively long and tapered ( Fig. 21 a) Currently known only from northeastern QLD ( Fig. 28 a).............................. A. cincta (Mocsáry)

- Scutellum with a prominent dorsal cream or yellow maculation (Thorax Grades 5–14, Figs 5 , 25 d). Frons and mesepisternum with plumose and simple hair ( Figs 23 b–f, 25d). S6 median body broad ( Figs 20 l–o). Base of penis valve relatively short and broad ( Figs 21 b–c). Distribution: WA, NT, QLD, NSW...................................................... 2

2(1). Small bees, head width <1.60 mm ( Fig. 14 ), forewing including tegula ≤ 3.7 mm. Gonostylus tip with distinct subapical curve ( Figs 21 b, d). S6 median body tapering. S5 apical margin with protruding narrow lobes ( Figs 20 l, h). HBW 0.18–0.22 mm ( Fig. 13 ). Distribution: WA, NT ( Fig. 28 b)............................................. A. essingtoni (Cockerell)

- Larger bees, head width> 1.65 mm ( Fig. 14 ), forewing including tegula ≥ 3.8 mm. Gonostylus gently curved ( Figs 21 c, e). S6 median body parallel sided or with slight median constriction. S5 apical margin smooth or slightly curved ( Figs 20 m–o, i–j). HBW 0.22–0.29 mm ( Fig. 13 ). Distribution: WA, NT, QLD, NSW.............................................. 3

3(2). Mesepisternum plumose hairs narrow and feather-like, with short closely set barbs ( Fig. 25 d, f). Distribution: QLD ( Fig. 28 d)................................................................................... A. cassiae (Cockerell)

- Mesepisternum plumose hairs broad or irregular in shape, with longer sparser barbs ( Figs 25 e, g). Distribution: WA, NT, QLD, NSW.............................................................................................. 4

4(3). Mesepisternum plumose hairs usually with long evenly spaced barbs and a broad triangular shape ( Fig. 25 e). Distribution: WA, NT, QLD, NSW ( Fig. 28 c).............................................................. A. australis (Friese)

- Mesepisternum plumose hairs with long barbs at various angles and irregular in shape ( Fig. 25 g). Distribution: NT and far northwestern QLD ( Fig. 28 d)............................................................. A. magna sp. nov.

Figures

FIGURE 5. Thorax colour marking grades used to classify workers and males of Austroplebeia.

FIGURE 7. Variation in worker thorax colour grades observed within all Austroplebeia taxa except A. cincta. Data show 2503 workers from 158 colonies, in addition to 59 workers from 15 flower samples of A. australis – Western Colour Morph. Colour grades are as illustrated in Fig. 5.

FIGURE 8. Variation in male thorax colour grades observed within all Austroplebeia taxa except A. cincta and A. australis – Western Colour Morph. Data show 196 males from 38 colonies. Colour grades are as illustrated in Fig. 5.

FIGURE 13. Ratio of tibia III width and basitarsus III width in males of all Austroplebeia species. Data points are averages from 2 – 3 males per colony. Data from the male paratypes of A. magna sp. nov. are also shown. Names given in brackets in the legend are groups in our Halcroft et al. (2015) preliminary analysis.

FIGURE 14. Ratio of head width and tibia III length in males of all Austroplebeia species. Data points are averages from 2 – 3 males per colony. Data from the male paratypes of A. magna sp. nov. are also shown. Names given in brackets in the legend are groups in our Halcroft et al. (2015) preliminary analysis.

FIGURE 20. Austroplebeia male sterna and terga, shown in ventral view except for Fig. r. Figs a – f. S 4: a, A. cincta; b, A. essingtoni; c, A. australis; d – e, A. cassiae showing variation in position of gradulus; f, A. magna sp. nov. Figs g – j. S 5: g, A. cincta; h, A. essingtoni, arrow indicates protruding apical lobe; i, A. australis; j, A. cassiae. Figs k – o. S 6: k, A. cincta; l, A. essingtoni; m, A. australis; n, A. cassiae; o, A. magna sp. nov. Figs p – q. S 7: p, A. cincta; q, A. australis. Fig. r. T 7 of A. cassiae, dorsal view. Figs a – f, scale bar = 0.5 mm; figs g – r, scale bar = 0.33 mm. Abbreviations: Gra—gradulus; Med—median body.

FIGURE 21. Austroplebeia male genitalia. Figs a – c. Genitalia, dorsal view on left, ventral view on right: a, A. cincta; b, A. essingtoni; c, A. magna sp. nov. Figs d – e. Apical abdomen and protruding parts of genitalia, viewed laterally, as visible in many pinned male specimens: d, A. essingtoni, showing distinct curve in apical gonostylus; e. A. magna sp. nov., with gently curved apical gonostylus. Figs a – c drawn to same scale. Abbreviations: Pen—penis valve; Gon—gonostylus.

FIGURE 23. Austroplebeia male faces: a, A. cincta QLD; b, A. essingtoni; c, A. australis – Eastern Colour Morph; d, A. australis – Central Colour Morph; e, A. cassiae; f, A. magna sp. nov. Scale bars = 0.25 mm.

FIGURE 25. Austroplebeia lateral thoraces: Figs a – b. Worker mesosomal side: a, A. cincta QLD; b, A. cassiae. Figs c – d. Male mesosomal side: c, A. cincta QLD; d, A. cassiae. Figs e – g. Detail of mesepisternum pilosity on male mesosomal side (photographs by K. Walker): e, A. australis; f, A. cassiae; g, A. magna sp. nov. Figs e – g shown at same magnification; all scale bars = 0.25 mm. Abbreviation: Met—metepisternum.

FIGURE 28. Observed distribution of all Austroplebeia species in Australia and the island of New Guinea: a, A. cincta; b, A. essingtoni; c, A. australis; d, A. magna sp. nov. and A. cassiae. In all maps, square symbols represent nest samples and circles represent samples collected from flowers or traps. The type locality for each named species, including those now synonymised, is indicated with arrows. Where the type locality was a general area such as ' Central Australia' or ' Cape York', these areas are indicated with shading.