Nylanderia umbella

Identification
LaPolla et al. (2011) - Head width less than 0.51 mm; head, mesosoma, and gaster dark brown, contrasting sharply with yellowish-brown antennae, mandibles, mesocoxae, metacoxae, and legs; very short, angular, propodeal dorsal face.

Compare with: Nylanderia boltoni and Nylanderia scintilla

This is among the darkest of the Afrotropical species, with strongly contrasting antennae, coxae, and legs. Based on overall similarities in size and shape, N. umbella appears closely related to N. boltoni and N. scintilla.

Castes
The queen and male castes are currently unknown for this species.

Nomenclature

 *  umbella. Nylanderia umbella LaPolla & Fisher, in LaPolla, Hawkes & Fisher, 2011: 24, figs. 58-60, 85 (w.) CAMEROUN.

Worker
Measurements (n = 3): TL: 2.1–2.4; HW: 0.49–0.51; HL: 0.59–0.61; EL: 0.14–0.16; SL: 0.62–0.64; PW: 0.35–0.38; WL: 0.62–0.69; GL: 0.92–1.2

Indices: CI: 80–84; REL: 23–27; SI: 123–130

Overall dark brown, with lighter brown to yellow mandibles, antennae, and legs; cuticle smooth and shining; procoxae dark brown, with mesocoxae and metacoxae yellow-brown to yellow in color. Head with a dense layer of pubescence; posterior margin with rounded posterolateral corners, slightly emarginate medially; scapes surpass posterior margin by about the length of the first two funicular segments; scapes with scattered erect acrosetae and a dense layer of pubescence (SMC = 13–16). Mesosoma with erect macrosetae of varying lengths concentrated on posterior pronotum and mesonotum (PMC = 3–5; MMC = 2); layer of pubescence covers mesosomal notum; metanotal area compact; dorsal face of propodeum angular and low (lower than mesonotum) with very short dorsal face and longer declivitous face; propodeum dorsum with pubescence; declivity smooth and shining with no pubescence. Gaster with abundant erect macrosetae and a dense layer of pubescence.

Type Material
Holotype worker, CAMEROON: Mbalmayo, xi.1993 (N. Stork) ; 3 paratype workers, same label data as holotype (BMNH)

Etymology
The species epithet umbella (L. = shade or shadow) is in reference to the dark brown coloration of this species.