Austroplebeia Moure

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 : 22-24

publication ID	https://doi.org/ 10.11646/zootaxa.4047.1.1
publication LSID	lsid:zoobank.org:pub:5A09E35D-3019-4F99-8A77-B7E2E637804D
DOI	https://doi.org/10.5281/zenodo.6097063
persistent identifier	https://treatment.plazi.org/id/03DF87DD-A314-FFB4-8589-EE273A5FFC63
treatment provided by	Plazi
scientific name	Austroplebeia Moure
status

Treatment

Genus Austroplebeia Moure View in CoL

Austroplebeia Moure 1961: 195 View in CoL . Type species: Austroplebeia cassiae ( Cockerell 1910) View in CoL by original designation.— Michener 1990: 133.

Trigona (Plebeia) View in CoL — Michener 1965: 230.

Diagnosis of genus Austroplebeia . Workers small, dark and robust, body length 3.0– 4.9 mm. Scutellum short and rounded, only slightly over-roofing metanotum ( Figs 25 View FIGURE 25 a–d). Scutellum and face usually with cream to yellow maculations ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 , 5 View FIGURE 5 , 22–25 View FIGURE 22 View FIGURE 23 View FIGURE 24 View FIGURE 25 ). Tibia III inner surface with broad keirotrichiate area, nearly reaching upper margin of tibia ( Figs 19 View FIGURE 19 a, e). Basitarsus III inner surface uniformly covered with bristles, sericeous area absent ( Figs 19 View FIGURE 19 a, e). Distribution: Australia and New Guinea ( Fig. 28 View FIGURE 28 ).

General description of the Australian and New Guinean Austroplebeia .

Worker. Structure. Head wider than thorax. Head width 1.2–1.3x head length. Face shape almost quadrate, inner orbits weakly converging below ( Fig. 22 View FIGURE 22 ). Gena rounded, narrower than the eye, viewed laterally. Occipital edge not carinate. Frons slightly convex with medial depression. Interantennal area and supra-antennal area with a triangular medial elevation. Clypeus short, slightly convex. Labrum short and simple in shape, apical margin smooth and rounded. Malar area short, length usually 0.2–0.3x basal mandible width. Mandible with two acutely pointed preapical teeth ( Figs 17 View FIGURE 17 d–h). Giant hairs on labial palpus curved or hooked, occasionally weakly sinuous ( Figs 17 View FIGURE 17 o–q). Flagellar segments shorter than wide. F1 trapezoid, dorsal margin longer than ventral margin, similar in length to F2 and F3 ( Fig. 17 View FIGURE 17 a). Scape not reaching level of lateral ocellus.

Scutellum short and rounded, slightly over-roofing metanotum. Propodeum large and bowed ( Figs 25 View FIGURE 25 a–b). Wing venation shown in Fig. 18 View FIGURE 18 . Submarginal angle (measured between Rs and Rs+M) slightly acute to 90o. Abdomen slightly broader than thorax.

Mesotibial spur ( Oliveira 2002) straight and ca. 0.33x basitarsus II length ( Fig. 19 View FIGURE 19 d). Tibia III approximately triangular with posterior margin curved. Corbicula shallow. Inner surface of tibia III with broad keirotrichiate area on median elevation, posterior margin shiny and only slightly depressed ( Figs 19 View FIGURE 19 a, c).

Sting rudiments. Gonostyli close together at base, parallel or diverging slightly, with bands of long coarse bristles laterally and abundant dense fine hair medially. Sting stylet (or bulb) usually with apex broadly rounded, occasionally with a short, narrowly rounded or acute medial protusion. Sting lancet (first valvula or first ramus) long and free, apex attaining at least base of gonostylus ( Fig. 16 View FIGURE 16 ).

Colour. Variable extents of cream or yellow maculations on supraclypeal area, clypeus, paraocular area, labrum, scape, pronotal collar, pronotal lobe, tegula, lateral scutum, scutellum, metepisternum ( A. cincta ), terga, sterna and legs.

Frons, paraocular area and gena black or dark brown, sometimes red-brown. Unmarked areas of clypeus usually dark brown or red-brown ( Fig. 9 View FIGURE 9 ). Mandible usually black or dark brown basally, orange-brown or redbrown medially ( Fig 9 View FIGURE 9 ), red-brown or dark brown apically. Flagellum usually brown or yellow-brown, dark brown in QLD A. cincta . Scutum usually black in mature specimens, but occasionally dark brown even in foragers caught on flowers. Mesosomal sides, propodeum and metanotum usually black to red-brown. Pronotal lobe usually cream, yellow in A. cincta . Wings hyaline, slightly brownish in A. cincta . Veins and stigma dark brown to yellow-brown. Unmarked areas of tibia III black to orange-brown. Distitarsus orange-brown to yellow-brown.

Pilosity. Face with numerous short simple and plumose hairs ( Fig. 22 View FIGURE 22 ). Vertex with long erect bristles. Malar space evenly covered with short fine appressed hair.

Scutum with an even layer of fine short hair, admixed (except in A. cincta ) with longer erect simple hairs, sparse long hairs on lateral margins. Scutellum with a fringe of longer bristles. Mesepisternum with semi-erect simple hair, longer ventrally, admixed (except in A. cincta ) with plumose hair ( Figs 25 View FIGURE 25 a–b). Pronotal lobe, hypoepimeral area, dorsal metepisternum and propodeal sides with dense simple or plumose hair. Propodeal triangle hairless, or nearly so. T1 to T6 apically with simple hairs, becoming denser and longer on posterior terga. Sterna with fine erect simple hair, very dense and often with curved tips.

Leg hair almost entirely simple. Tibia III with fringes of bristles on anterior and posterior edges. Corbicula on outer tibia III hairless except for 4–10 long (up to 275 Μm) simple hairs. Tibia III inner surface with keirotrichiate area of short blunt bristles. Rastellum bristles slender and pointed. Basitarsus III outer surface with pale simple bristles, inner surface covered in coarse bristles without sericeous area ( Figs 19 View FIGURE 19 a–c).

Surface sculpture. Face and scutum shiny with numerous fine punctures, spacing 1– 2 x puncture diameter. Terga shiny. Propodeal triangle, apical margins of terga and corbicular surface with fine reticulate sculpturing.

Male. As described for the worker, except for the usual secondary sexual characters and as follows: Structure. Face wedge-shaped. Eyes large, inner orbits very slightly concave, strongly converging below ( Fig. 23 View FIGURE 23 ). Gena rounded, much narrower than the eye, viewed laterally. Frons convex with a marked medial depression. Interantennal area and supra-antennal area with a prominent triangular medial elevation. Malar area very short anteriorly, widening posteriorly. Mandible short, narrowed apicad, with one preapical tooth on upper margin ( Figs 17 View FIGURE 17 i–m). Flagellum longer than in workers (1.5–1.7x). F1 trapezoid and very short ( Fig. 17 View FIGURE 17 b). Scape shorter than in workers (0.8x).

Scutellum length 0.4–0.5x width. Propodeum large and bowed ( Figs 25 View FIGURE 25 c–d).

Tibia III simple, outer surface uniformly convex, distal corner moderately angled, inner surface with broad keirotrichiate area, posterior slope of inner surface almost uniformly level ( Figs 19 View FIGURE 19 e–f).

Terminalia and genitalia. T7 gently rounded with long curved hairs. S6 with a median apical process (or median body). S7 reduced to a small plate ( Fig. 20 View FIGURE 20 ). Spatha absent. Penis valve heavily sclerotised, tapering, curved, clawlike. Gonostylus long, slender and simple ( Fig. 21 View FIGURE 21 ).

Colour. Cream or yellow maculations usually more extensive than in workers, but metepisternum and dorsal scutellum of A. cincta without maculations ( Figs 25 View FIGURE 25 c–d).

Frons, paraocular area and gena black or dark brown. Unmarked areas of clypeus usually dark brown or redbrown ( Fig. 9 View FIGURE 9 ). Labrum cream or yellow-brown. Mandible usually cream or yellow-brown ( Fig. 9 View FIGURE 9 ), sometimes brown to red-brown apically. Unmarked areas of scutum black. Mesosomal sides and propodeum black to redbrown. Pronotal lobe usually cream, yellow in A. cincta . Wings hyaline. Veins and stigma dark brown to yellowbrown. Unmarked areas of tibia III usually red-brown. Mediotarsus and distitarsus brown to cream.

Pilosity. Generally as in workers, except: distal terga with simple hairs not as dense as in workers. Sterna with erect pale simple hairs, denser on apical margins, S5 with a row of stiff bristles on the border which are progressively longer laterad ( Figs 20 View FIGURE 20 a–j).

Leg hair appears entirely simple. Tibia III outer surface evenly distributed with sparse short simple hairs, inner surface with keirotrichiate area of short blunt bristles ( Figs 19 View FIGURE 19 e–f).

Surface sculpture. Similar to worker.

Queen. As in worker, except for the following differences:

Structure. Face shape slightly more quadrate. Eyes shorter than in workers ( Fig. 24 View FIGURE 24 ): 0.90–0.95x in A. cincta and A. essingtoni , 0.8x in other species. Gena and eye approximately the same width, viewed laterally. Frontal outline of vertex more rounded than in workers. Malar area 3– 4 x longer. Mandible more slender than in workers ( Fig. 17 View FIGURE 17 n). Flagellum longer than in workers (1.3–1.4x), but shorter than in males (0.8–0.9x). F1–F3 similar in length ( Fig. 17 View FIGURE 17 c). Scape reaching level of lateral ocellus, or slightly longer.

Scutum 0.8–0.9x shorter than in workers, scutellum flattened on dorsal surface, not over-roofing metanotum.

Tibia III simple, corbicula absent, outer surface uniformly convex except for apical margin, inner surface with broad keiotrichiate area. Basitarsus III narrower and slightly longer than in workers ( Fig. 19 View FIGURE 19 g).

Colour. Difficult to score as many specimens were callow. Based on the darkest specimens in both castes, cream or yellow maculations usually in same range or slightly more extensive than in conspecific workers

Pilosity. Face in A. cincta and A. essingtoni with plumose hair absent, or nearly so. Scutellum bristles 1.4–2.4x longer than in workers. Mesepisternum dorsal area with fine dense hair, medial area with very short simple hairs (appearing shiny and almost hairless), ventral area with longer (up to 250 Μm) simple hairs. Propodeal sides with fine simple or weakly plumose hair.

T1–T5 with very sparse short simple hairs (T1–T 3 in A. cassiae ). T6 with an even layer of dense short fine hair (T4–T 6 in A. cassiae ) ( Fig. 27 View FIGURE 27 ). Broad band of coarse bristles between T2 and T3 which are covered by the apical margin of T 2 in virgin queens but exposed in fresh specimens of gravid queens (not able to be verified in A. essingtoni ). Sterna with one or two rows of coarse short (175–275 Μm) straight bristles on apical margin.

Tibia III with numerous coarse bristles covering entire outer surface ( Fig. 19 View FIGURE 19 g), admixed (except in A. cincta and A. essingtoni ) with some fine plumose hair. Rastellum represented by irregular widely spaced bristles.

Surface sculpture. Similar to worker.