Geniotrigona lacteifasciata (Cameron)

Rasmussen, Claus, Thomas, Jennifer C. & Engel, Michael S., 2017, A New Genus of Eastern Hemisphere Stingless Bees (Hymenoptera: Apidae), with a Key to the Supraspecific Groups of Indomalayan and Australasian Meliponini, American Museum Novitates 2017 (3888), pp. 1-36 : 15-18

Geniotrigona lacteifasciata (Cameron)

Figures 1C , 2B, 2D , 11D

Trigona lacteifasciata Cameron, 1902: 131 .

Trigona borne ë nsis Friese, 1933a: 46. Synonymy vide Schwarz (1939).

Trigona thoracica variety lacteifasciata Cameron ; Schwarz, 1937: 317.

Trigona thoracica variety borne ë nsis Friese; Schwarz, 1937: 328.

Geniotrigona lacteifasciata (Cameron) ; Moure, 1961: 213.

MATERIAL EXAMINED (n = 21⚲⚲): MALAYSIA: Sabah (Borneo): 1⚲, Malaysian Borneo: Sabah, Kampung Bam Bam (20 km SW of Tenom), 06-VIII-2009 [6 August 2009], R.S. Hepburn ( SEMC) ; 2⚲⚲, Malaysia: Sabah (Borneo), Penampang Distr. , Crocker Range , Kipandi Butterfly Park , 720 m, 5°52’20’’N, 116°14’53’’E, 15.x.2011 [15 October 2011], M. Hauser and S. Gaimari ( SEMC, CSCA) ; 10⚲⚲, Malaysia, Sabah, near Sek. Keb. Labang, at the Sapulut River , 20–27.vii.2005 [20–27 July 2005], 300 m, Claus Rasmussen leg. ( CRCD) ; 1⚲, Sabah, Babagon , 7.vii.1968 [7 July 1968], P.J.L. Roche ( SEMC) ; 1⚲, Sabah, Sandakan , 3.viii.1985 [3 August 1985], C.G. Roche ( SEMC) ; 1⚲, Sabah, Sepilok F.R., 14.vii.1968 [14 July 1968], C.G. Roche ( SEMC) ; Sarawak (Borneo): 1⚲, Lundu , Sarawak, April 1913 ( AMNH) ; INDONESIA: West Kalimantan: 4⚲⚲, Borneo, Sanggau [Sanggau Regency], 24.7.32 [24 July 1932] ( AMNH) .

Key to Indomalayan and Australasian Genera and Subgenera of Meliponini (based on worker caste)

Given the introduction of a new genus along with the significant alteration of the generic classification (e.g., Rasmussen, 2008) since Michener’s (2007) recent key to the fauna, we provide here a new dichotomous identification key to the genera and subgenera as conceived herein.

1.Forewing length less than 3 mm, wing venation greatly reduced (fig. 7) and posterior margin of metatibia without plumose setae; hind wing without closed cells, veins closing radial and cubital cells, if visible at all, clear and unpigmented (spectral); forewing with 2Rs and 1rs-m almost always completely absent, thus without indication of submarginal cells (fig. 7); at least distal part of second cubital cell of forewing undefined or defined completely by unpigmented spectral vein traces (i.e., at least 2Cu and 3Cu absent or spectral); vein M of forewing terminating without bend at about position of anterior end of 1m-cu which, however, is absent (i.e., 3M lacking).............................................. 2

–Forewing length typically over 4 mm, wing venation typically not greatly reduced for Meliponini , but if minute and with some wing reduction, then posterior margin of metatibia with plumose setae intermixed with simple setae; hind wing typically with radial and cubital cells closed by at least weakly brownish nebulous veins; forewing with one or two submarginal cells usually weakly indicated by nebulous traces of 2Rs and 1rs-m (fig. 3D), first submarginal cell usually recognizable; second cubital cell of forewing completely indicated by at least faint nebulous veins (i.e., 2Cu present); vein M of forewing usually extending at least slightly beyond position of 1m-cu and angular at apex of tubular portion of vein (i.e., 3M present) (fig. 3D), the stub of which is usually at least faintly visible.............. 3

2.Malar space shorter than flagellar diameter (fig. 7B); inner margins of compound eyes converging below (fig. 7B); worker gonostylus with many minute setae, in addition to setae along outer and distal margins ( India; Vietnam; Laos; Cambodia; Thailand; Malaysia: Sarawak, Sabah; Indonesia: Sumatra)................................. Lisotrigona Moure

–Malar space almost one-fifth as long as compound eye, much longer than flagellar diameter (fig. 7C); inner margins of compound eyes nearly parallel (fig. 7C); worker gonostylus with setae but without minute setae ( Thailand; Malaysia: West Malaysia, Sarawak, Sabah; Brunei; Indonesia: Sumatra)........................................ Pariotrigona Moure

3.Head and mesosoma without distinct maculation; inner surface of metatibia with strong longitudinal keirotrichiate ridge above which is a broad, depressed shining marginal area... 4

–Mesoscutellum and usually face and mesoscutum with well-developed yellow maculation (figs. 8A, 8B); inner surface of metatibia with keirotrichiate area broad, nearly reaching posterior margin of metatibia (figs. 8C, 8D) ( Australia; Papua New Guinea; Indonesia: Irian Jaya [West Papua])............................................ Austroplebeia Moure

4.Setae along posterior margin of worker metatibia and males entirely simple, or some plumose only on apical one-fifth or one-sixth of margin; keirotrichiate median zone of inner surface of metatibia separated from shining posterior marginal zone by gentle slope.......... 5 –Setae along posterior margin of worker metatibia and some males partly plumose; elevated keirotrichiate median zone of inner surface of metatibia separated from shining posterior marginal zone by abrupt slope................................................... 6

5.Mesoscutum margined with whitish, densely plumose (scalelike) setae (fig. 9A); head and mesosoma dull, with minute close punctures (fig. 9A); propodeal dorsum finely reticulate (fig. 9C); posterior margin of worker metatibia without plumose setae (fig. 9E); (Indomalaya [Sundaland])............................................. Lepidotrigona Moure

–Mesoscutum without conspicuous plumose setae (fig. 9B); head and mesosoma shining, although with minute, rather close punctures (fig. 9B); propodeal dorsum smooth, shining; posterior margin of worker metatibia with plumose setae among bristles on apical one-fifth or one-sixth of margin ( Indonesia: Irian Jaya [West Papua]; Papua New Guinea).................................................... Papuatrigona Michener and Sakagami

6.Mesoscutellum short, only slightly projecting over metanotum (best seen in profile, fig. 11A); malar area variable, typically as long as diameter of diameter of third flagellomere or greater but sometimes approximately 0.5–0.75× diameter of third flagellomere; vein M of forewing bent at trace of 1m-cu, sometimes present only as minute stub beyond bend (e.g., fig. 3D)....... 7

–Mesoscutellum well projected posteriorly, extending over propodeum as far as posterior propodeal angle (change in slope between basal area and posterior surface) (best seen in profile, fig. 11B); malar area linear or at least narrower than 0.5× diameter of third flagellomere; vein M of forewing straight and ending at or shortly after 1m-cu (fig. 10) ( Tetragonula Moure , s.l.)....................................................... 10

7.Malar space less than 2× diameter of third flagellomere............................... 8

–Malar space 2× or greater diameter of third flagellomere (figs. 2, 3A, 3B, 6A, 6B)......... 9

8.Mandible unidentate or bidentate, teeth small ( Heterotrigona Schwarz , s.l.)............. 11

–Mandible bidentate, teeth large, deeply incised, i.e., interdental spaces deep (fig. 9D) ( Homotrigona Moure , s.l.).............................................................. 14

9.Vertex with deep depression and elevated ridge rising above level of ocelli (figs. 6A, 6B), posteriorly without deep, concave, medial notch; mesoscutum with dense covering of short, plumose setae amid scattered erect, black setae; apical metasomal terga with dense, long, apically plumose setae amid erect, black setae, with plumose setae at least as long as black setae (fig. 11D); keirotrichiate zone of metatibial inner surface narrower than posterior glabrate zone, and greater than length of apical glabrate zone (figs. 4C, 4D, 5B) ( Myanmar; Cambodia; Thailand; Singapore; Malaysia: West Malaysia, Sarawak, Sabah; Indonesia: Kalimantan, Sumatra)......................................... Geniotrigona Moure

–Vertex without strongly elevated ridge, with faint transverse depression and ridge posterior to ocelli (fig. 3A), posteriorly with deep, concave medial incision (fig. 11E); mesoscutum without dense covering of short, plumose setae amid scattered erect, black setae; apical metasomal terga with short, scattered plumose setae amid longer, erect, black setae; keirotrichiate zone of metatibial inner surface about as broad as or slightly broader than posterior glabrate zone, and subequal to length of apical glabrate zone (figs. 4A, 4B, 5A) ( Indonesia: Sulawesi)........................................ Wallacetrigona , n. gen. 10. Scape shorter than torulocellar distance; about five distal hamuli; posterior contour of metatibia slightly convex, with distal angle subangulate; penicillus usually composed of soft setae ( India to Australia and Solomon Islands)............... Tetragonula Moure , s.str.

–Scape at least as long as torulocellar distance; six distal hamuli; posterior contour of metatibia distinctly convex and distal angle rounded almost without angulation; penicillus composed of stiff setae ( Cambodia; Vietnam; Laos; Myanmar; Thailand; Malaysia: West Malaysia, Sarawak, Sabah; Brunei; Indonesia: Sumatra, Kalimantan)........... Tetragonilla Moure

11. Basal area of propodeum largely or entirely glabrous, at most with wispy apicolateral patches of setae............................................................... 12

–Basal area of propodeum entirely pubescent (fig. 11C), or with a small medial glabrous patch (in H. hobbyi (Schwarz)) ( Indonesia: Irian Jaya [West Papua, Papua], Moluccas; Papua New Guinea)...................................................... Platytrigona Moure

12. Basal vein (1M) of forewing basad 1cu-a........................................ 13

–Basal vein (1M) of forewing distad 1cu-a ( Indonesia [Papua]; Papua New Guinea)...................................................... Sahulotrigona Engel and Rasmussen

13. Posterior glabrate zone of metatibial inner surface apically broader than keirotrichiate zone; forewing length more than 5.5 mm ( Thailand; Singapore; Malaysia: West Malaysia, Sarawak, Sabah; Brunei; Indonesia: Java, Sumatra, Kalimantan)............................................................................ Heterotrigona Schwarz , s.str.

–Posterior glabrate zone of metatibial inner surface apically narrower than or at most as broad as keirotrichiate zone; forewing length less than 6.0 mm ( Singapore; Malaysia: West Malaysia, Sarawak; Indonesia: Sumatra)................... Sundatrigona Inoue and Sakagami

14. Basal sericeous area of metabasitarsus present; clypeus approximately 2× broader than long........................................................................ 15

–Basal sericeous area of metabasitarsus absent; clypeus short, at least 2.5× broader than long ( Thailand; Laos; Singapore; Vietnam; Cambodia; Indonesia: Sumatra, Kalimantan; Brunei; Malaysia: West Malaysia, Sarawak; Myanmar)............... Homotrigona Moure , s.str.

15. Basal area of propodeum smooth and glabrous; vertex not elevated posterior to ocelli..... 16

–Basal area of propodeum pubescent; vertex elevated posterior to ocelli ( Thailand; Malaysia: West Malaysia, Sarawak, Sabah; Singapore; Indonesia: Sumatra, Kalimantan; Myanmar; Sri Lanka; Australia)............................................. Lophotrigona Moure

16. Malar space as long as flagellar diameter; clypeus with a transverse row of erect setae along apical margin; metabasitarsus 2× as long as wide ( Cambodia; Malaysia: Sarawak, Sabah, West Malaysia; Brunei; Myanmar; Indonesia: Sumatra, West Timor, Kalimantan; East Timor; Thailand; Laos; Vietnam)................................... Tetrigona Moure

–Malar space about as long as 1.5× flagellar diameter; clypeus with erect black setae scattered over entire surface; metabasitarsus less than 1.5× as long as wide ( Malaysia: Sarawak, Sabah; Brunei).............................................. Odontotrigona Moure

Figures

FIGURE 1. Lateral habitus of workers. A. Wallacetrigona incisa (Sakagami and Inoue). B. Geniotrigona thoracica (Smith). C. G. lacteifasciata (Cameron).

FIGURE 2. Facial views and mouthparts of workers. A. Facial view of Wallacetrigona incisa (Sakagami and Inoue). B. Facial view of G. lacteifasciata (Cameron). C. Facial view Geniotrigona thoracica (Smith). D. Lateral view of extended mouthparts of G. lacteifasciata, note erect, hooked setae of galea and wavy setae of basal labial palpomeres.

FIGURE 11. Anatomical details of various genera of Indomalayan and Australasian genera of Meliponini. A. Profile of upper mesosoma of Heterotrigona (Heterotrigona) itama (Cockerell). B. Profile of upper mesosoma of Tetragonula (Tetragonilla) collina (Smith). C. Propodeum of Homotrigona (Lophotrigona) canifrons (Smith). D. Metasomal apex of Geniotrigona lacteifasciata (Cameron). E. Ocellar triangle and medial vertex of Wallacetrigona incisa (Sakagami and Inoue), with arrow indicating posterior, medial, U-shaped incision.