Meliponini

Engel, Michael S. & Rasmussen, Claus, 2017, A new subgenus of Heterotrigona from New Guinea (Hymenoptera: Apidae), Journal of Melittology 2017 (73), pp. 1-16 : 14

Key to Genera and Subgenera of Papuasian Meliponini

1. Head and mesosoma without distinct maculation; inner surface of metatibia with strong longitudinal keirotrichiate ridge above which is a broad, depressed shining marginal area ............................................................................. 2

—. Mesoscutellum and usually face and mesoscutum with well-developed yellow maculation; inner surface of metatibia with keirotrichiate area broad, nearly reaching upper margin of metatibia ....................... Austroplebeia Moure

2(1). Setae along posterior margin of worker metatibia and some males partly plumose; clivulus bordering elevated keirotrichiate median zone of inner surface of metatibia forming abrupt slope ................................................................ 3

—. Setae along posterior margin of worker metatibia and males at most plumose on apical one-fifth or one-sixth of margin; clivulus bordering keirotrichiate median zone of inner surface of metatibia forming gentle slope to shining posterior glabrate zone ......................... Papuatrigona Michener & Sakagami

3(2). Mesoscutellum short, not or only slightly projecting over metanotum; 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 (genus Heterotrigona Schwarz ) ...... 4

—. Mesoscutellum well projected posteriorly, extending over propodeum as far as posterior propodeal angle (change in slope between basal area and posterior surface); 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 .......................................................................................... Tetragonula Moure

4(3). Basal area of propodeum glabrous, at most with apicolateral patches of setae; basal vein distad 1cu-a ............... Heterotrigona (Sahulotrigona) , n. subgen.

—. Basal area of propodeum pubescent; basal vein either confluent with or distad 1cu-a .......................................................... Heterotrigona (Platytrigona) Moure