Nylanderia microps

Morphology features (small eyes, light pigmentation) and that foragers have not been seen during the day suggests this species is nocturnal.

Identification
LaPolla and Kallal (2019) - Very small eyes (EL less than 0.1 mm); orange-yellow; entire body with abundant macrosetae (SMC: 38–47; PMC: 24–27) giving species a prickly appearance. Compare with: Nylanderia myops, Nylanderia zaminyops.

Along with N. myops and N. zaminyops, N. microps is another West Indian species with reduced eye size (EL less than 0.1 mm). While all species are light in coloration, N. myops and N. zaminyops are much paler and do not possess nearly as many macrosetae on the scapes and mesosomal dorsum. Among West Indian Nylanderia, N. microps is unusually setose. The presence of very short, nearly appressed macrosetae along the anterior portion of the propodeal dorsal face is unusual as well. A similar character state has been observed in Nylanderia mixta, a species endemic to the Seychelles in the southwest Indian Ocean (LaPolla and Fisher, in prep).

Distribution based on Regional Taxon Lists
Neotropical Region: Greater Antilles, Puerto Rico.

Biology
LaPolla and Kallal (2019) - It seems reasonable to assume this species is nocturnal given its small eyes and light coloration. One of us (JSL) collected several colonies of N. microps around El Verde Field Station, and workers were never observed foraging during the day. Colonies were interestingly found in trees, usually about 1–2 meters off the ground. They were found to nest in rotten pieces of wood and under bark where soil and leaves had accumulated in a groove or flat part of a tree branch. Hundreds of workers were found in the colonies, but unfortunately males were never collected. Interestingly, this species occurs in sympatry with Zatania cisipa in the El Yunque National Forest, which also nests in trees and is nocturnal (LaPolla et al. 2012). A molecular phylogeny of Nylanderia placed this species as sister species to the other Puerto Rican species described here, Nylanderia semitincta.

Nomenclature

 *  microps. Prenolepis (Nylanderia) microps Smith, M.R. 1937: 868 (w.) PUERTO RICO. Combination in Nylanderia: Kempf, 1972a: 167; in Paratrechina: Brandão, 1991: 367; in Nylanderia: LaPolla, Brady & Shattuck, 2010a: 127.

Worker
LaPolla and Kallal (2019) - (n=5): TL: 2.40–3.20; HW: 0.55–0.73; HL: 0.67–0.81; EL: 0.05–0.08; SL: 0.77– 0.93; WL: 0.78–1.00; GL: 0.90–1.50. SMC: 38–47; PMC: 24–27; MMC: 5–10. indices: CI: 82–89; REL: 7–10; SI: 128–139; SI2: 6–9.

Head: sides of head in full face view nearly parallel; posterolateral corners rounded; posterior margin straight, slightly emarginate medially; anterior clypeal margin evenly rounded; ocelli absent; eye small. Mesosoma: in lateral view, pronotum convex; anterior margin of mesonotum raised slightly above posterior pronotal margin; metanotal area with a short flat area before spiracle; dorsal face of propodeum slightly convex; dorsal face of propodeum lower than mesonotum in lateral view. Color and pilosity: body orange-yellow; legs and gaster sometimes slightly lighter, especially ventrally on gaster; scape and legs with abundant pubescence, pubescence sparse to absent across remainder of body; macrosetae distinctly abundant across entire body, with dark setal bases, giving specimens prickly appearance; anterior portion of propodeal dorsal face with fringe of nearly appressed, very short macrosetae (more or less in a line across dorsal face, pointing toward head).

Type Material
LaPolla and Kallal (2019) - Syntype worker, PUERTO RICO: 14 kilometers east of Mayagüez (M.R.S.) (examined).

References based on Global Ant Biodiversity Informatics

 * Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * LaPolla J. S., and R. J. Kallal. 2019. Nylanderia of the World Part III: Nylanderia in the West Indies. Zootaxa 4658: 401-451.
 * Smith M. R. 1937. The ants of Puerto Rico. Journal of Agriculture of the University of Puerto Rico 20: 819-875.
 * Torres J.A. 1984. Niches and Coexistence of Ant Communities in Puerto Rico: Repeated Patterns. Biotropica 16(4): 284-295.