Nylanderia trageri

Nests are found in leaf litter and in rotten branches. The time of reproductive flight is unknown. Previously, it was noted as a morph of Nylanderia parvula, but the presence of distinct uniformly yellow specimens collected in multiple areas, and preliminary molecular analyses (S.G. Brady, unpublished data) indicate it is a separate species (Kallal & LaPolla, 2012).

Identification
Kallal & LaPolla (2012) - Small (TL: 1.3–2.3), yellow species with no macrosetae on scapes.

Compare with: Nylanderia parvula.

This species is very distinct in its appearance. It lacks scape macrosetae, as does N. parvula, but its uniform yellow coloration contrasts distinctly with the dark brown N. parvula.

Distribution
Collections have been made at elevations between 200 and 750 m in the central U.S., particularly in the Ouachita highlands and surrounding areas (Kallal & LaPolla, 2012).

Distribution based on Regional Taxon Lists
Nearctic Region: United States.

Nomenclature

 *  trageri. Nylanderia trageri Kallal & LaPolla, 2012: 35, figs. 49-51, 73, 157-164, 199 (w.q.m.) U.S.A.

Worker
Measurements (n=9) TL: 1.20–2.27; HW: 0.44–0.52; HL: 0.55–0.61; EL: 0.14–0.17; SL: 0.56–0.67; PW: 0.32–0.39; WL: 0.60–0.76; GL: 0.54–1.05; PH: 0.17–0.32; PFL: 0.43–0.55; PFW: 0.13–0.16. SMC: 0; PMC: 2–4; MMC: 2–3. Indices: CI: 78–85; REL: 25–29; SI: 103–118; FI: 78–91.

Uniform yellow in color, sometimes with lighter mesocoxae, metacoxae, and legs; cuticle smooth and shiny; cephalic pubescence moderate, mesosoma and gastral pubescence absent; pubescence yellow, macrosetae brown. Head relatively quadrate; posterior margin not emarginated medially; scapes surpass posterior margin by first 3–4 funicular segments; ocelli apparent. Pronotal anterior face at approximately 45° or less; pronotum inflected with pronotal anterior face shorter than pronotal dorsal face; anterior margin of mesonotum continuous with pronotal margin; propodeum rounded with longer declivitous face.

Queen
Measurements (n=2) TL: 3.54–4.25; HW: 0.68–0.71; HL: 0.74–0.76; EL: 0.24; SL: 0.78; PW: 0.77–0.83; MW: 0.70–0.84; WL: 1.17–1.27; GL: 1.61–2.24; PH: 0.37–0.38; PFL: 0.67–0.69; PFW: 0.19–0.21. SMC: 0; PMC: 3–5; MMC: 7–8; MtMC: 2–4. Indices: CI: 92–93; REL: 31–33; SI: 102–107; FI: 90–91.

Brown to yellowish-brown, with scapes, mandibles, leg articulations, and tarsi lighter in color; cuticle smooth and shiny; densely pubescent, macrosetae brown. Head less broad than it is long; scapes surpass posterior margins by 3–4 funicular segments. Propodeum with short dorsal face and long declivitous face.

Male
Measurements (n=1) TL: 2.10; HW: 0.48; HL: 0.51; EL: 0.19; SL: 0.56; PW: 0.42; MW: 0.39; WL: 0.73; GL: 0.87; PH: 0.28; PFL: 0.57; PFW: 0.11; PL: 0.20. SMC: 0; MMC: 7; MtMC: 2. Indices: CI: 93; REL: 38; SI: 110; FI: 112.

Brown to brownish yellow with scapes, mandibles, and legs yellowish; cuticle smooth and shiny; cephalic pubescence sparse to moderate; mesonotum with dense pubescence; gastral pubescence virtually absent; macrosetae brown. Head longer than broad; eyes convex, extending beyond the lateral margins of the head in full face view; scapes surpass posterior margin by first 4 funicular segments; inner mandibular margin long and straight; basal angle approximately 90°; masticatory margin with one subapical tooth and large apical tooth. Mesosoma enlarged to accommodate flight muscles; propodeum with longer dorsal face. Genitalia: parameres laterally oriented, triangular, becoming digitiform distally; digiti and cuspides sculptured as N. faisonensis, N. parvula, and others with digiti about as long as aedeagal valves; cuspides about half as long, both with rounded teeth where they meet; aedeagal valves triangular, teeth absent; ninth sternite triangular, posteriorly medially emarginated, becoming broader proximally to nearly flat lateral margins, with short lateral apodemes and long, slender ventral apodeme.

Etymology
Named to honor Dr. James C. Trager, who not only previously treated most of the Nearctic species, but also noted the yellowish morphs of N. parvula which molecular data has indicated are a separate species. His taxonomic work on Nylanderia provides a firm and indispensible foundation to our efforts to monograph the world’s Nylanderia species.

References based on Global Ant Biodiversity Informatics

 * Kallal R. J, and J. S. Lapolla. 2012. Monograph of Nylanderia (Hymenoptera: Formicidae) of the world, part II: Nylanderia in the Nearctic. Zootaxa 3508: 1-64.