Tetragonula ( Tetragonula ) sarawakensis ( Schwarz, 1937 )

Engel, Michael S., Michener, Charles D. & Boontop, Yuvarin, 2017, Notes on Southeast Asian Stingless Bees of the Genus Tetragonula (Hymenoptera: Apidae), with the Description of a New Species from Thailand, American Museum Novitates 2017 (3886), pp. 1-17 : 11-12

Tetragonula ( Tetragonula) sarawakensis ( Schwarz, 1937)

Trigona sarawakensis Schwarz, 1937: 313 . Cotype workers (AMNH, examined by M.S.E. and C.D.M.). Trigona (Tetragona) sarawakensis var. sarawakensis Schwarz ; Schwarz, 1939: 106.

Tetragonula sarawakensis (Schwarz) ; Moure, 1961: 210.

Trigona ( Tetragonula) sarawakensis (Schwarz) ; Sakagami, 1978: 210.

Since this is not a well-known species, we include below notes based on a series of workers in the AMNH, two labeled as cotypes, and include comparative information on T. malaipanae in brackets.

DESCRIPTIVE NOTES: Setae of clypeus and lower face minute, minutely if at all plumose, not at all hiding smooth surface [broadly plumose, partially hiding surface which shows some punctation]; tegula ferruginous [dark testaceous, sometimes grading to dusky especially near inner margin]; mesoscutellum with posterior extremity (overhanging propodeum) with transverse yellow mark (sometimes ferruginous, perhaps artificially darkened in such instances owing to method of collection or changes resulting from long-term preservation) [no such mark or if mark recognizable, testaceous or dusky]; legs ferruginous [usually dull ferruginous or brown with dusky areas at least on meso- and metatibiae]; setae of legs whitish or yellowish, sometimes a few dusky setae on tibiae and basitarsi [some setae on tibiae and basitarsi dusky or blackish, large simple setae arising from corbicular surface black or dusky although marginal setae largely or partly yellowish]; metasoma entirely ferruginous [dusky brown to testaceous].

MATERIAL EXAMINED (7⚲⚲): 1⚲ [cotype], Sarawak, Mt. Dulit , 4000 ft, moss forest, 18.x.1932 [ 18 October 1932], Oxford Univ. Exp. B.M. Hobby & A.W. Moore ( AMNH) ; 1⚲ [cotype], same data as preceding specimen except 19.x.1932 [ 19 October 1932] ( AMNH) ; 5⚲⚲, Mt. Tibang [Mount Tibang, Sarawak, near border with Kalimantan], 1300 m, Borneo, Nov. 1925, Eric Mjöberg ( AMNH) .