Nannotrigona Cockerell

Rasmussen, Claus & Gonzalez, Victor H., 2017, The neotropical stingless bee genus Nannotrigona Cockerell (Hymenoptera: Apidae: Meliponini): An illustrated key, notes on the types, and designation of lectotypes, Zootaxa 4299 (2), pp. 191-220 : 194-195

Genus Nannotrigona Cockerell

Nannotrigona Cockerell, 1922: 9 . Type species: Melipona testaceicornis Lepeletier de Saint Fargeau, 1836 , by original designation.

Diagnosis. Nannotrigona is easily recognized by the combination of the following features: mesoscutellum distinctly projecting posteriorly over metanotum and propodeum, with a shining V- or U-shaped median depression on anterior margin, notched or deeply emarginated medially on posterior margin, with a distinct white or yellow projection or tooth lateral to emargination; head and mesosoma, or at least on mesoscutellum, with extremely coarse punctation; and anterior margin of pronotal lobe with strong, transverse carina.

Comments. Three informal species groups can be recognized within Nannotrigona based on some distinctive features in the worker ( Table 1). The dutrae species group includes two very distinctive species [ N. dutrae (Friese) and N. schultzei (Friese) ] characterized by the sculpturing of the mesoscutum, which is glossy and sparsely punctate. This group is presumably, depending on the position of N. dutrae , the sister group to the remaining two groups, mellaria and testaceicornis , which are both characterized by the mesoscutum and mesoscutellum densely and coarsely foveate ( Rasmussen & Cameron, 2010). The mellaria and testaceicornis species groups differ in the length of the setae on the antennal scape (much shorter than the maximum width of the scape in the first, and at least as long as the maximum width of the scape in the second). The length of the setae on the scape is measured by rotating the specimen until the setae appear longest, often as seen pointing towards the midline of the face and positioned on the lower third of the scape.