Nylanderia pubens (Forel, 1893)

Diagnosis of worker among Antkey species. Worker caste monomorphic. Antenna 12-segmented. Antennal club indistinct. Antennal scape length less than 1.5x head length. Eyes medium to large (greater than 6 facets); do not break outline of head. Dorsum of mesosoma with weakly impressed metanotal groove, but never with a deep and broad concavity; dull with dense overlapping pubescence. Propodeum and petiolar node both lacking a pair of short teeth. Propodeum lacking posteriorly projecting protrusion. Mesopleuron shiny, not dulled by dense pubescence (less than 25 hairs). Metapleuron with a distinct gland orifice. Middle and hind coxae same color as mesosoma, not a strongly contrasting pale white. Waist 1-segmented (may be hidden by gaster). Petiole upright and not appearing flattened. Gaster armed with acidopore. Distinct constriction not visible between abdominal segments 3+4. Gaster (especially first segment) with dense pilosity, giving it a dull appearance. Hairs long thick and produced in pairs. Pubescence uniformly dense across mesosoma. Macrosetae on mesosoma long, flexuous and acuminate, strongly tapering to a fine tip. Body color reddish brown.

Among other introduced and commonly intercepted Nylanderia species, N. fulva can be distinguished from N. flavipes, N. guatemalensis, N. vaga and N. vividula by the dense amount of pubescence on the dorsal surfaces of the promesonotum, mesopleuron and first gastral segment. Of the two remaining species (N. bourbonica and N. steinheili) that have similarly dense pubescence in these regions, N. fulva is distinguished from the former by the more reddish brown color and the macrosetae which are long, flexuous and acuminate (versus moderate, stiff and blunt). Nylanderia fulva is easily distinguished from N. steinheili by the color of the coxae which are uniform with the rest of the legs and body (versus strongly contrasting white), and by the mesosomal pubescence which is uniformly dense across mesosoma (versus uneven, becoming denser on dorsum, more sparse laterally on pronotum and mesopleuron). The worker caste is morphologically indistinguishable from N. fulva. The males can be separated by the following characters: (1) paramere apices rounded and well sclerotized (dark brown coloration )(versus apices are triangular and weakly sclerotized (yellow to slightly darker coloration) in N. fulva); (2) macrosetae originating from the paramere margin fan-like  (versus scattered and not fan-like in N. fulva).