Nylanderia concinna

Trager (1984) notes alates may be produced any time of year, but that likely only applies to Gulf and Carolina populations known at the time.

Identification
Kallal & LaPolla (2012) - Uniformly dark brown with medium brown mandibles, scapes, mesocoxae, and metacoxae; conspicuous band of pubescence across anterior edge of propodeum.

Compare with: Nylanderia faisonensis, Nylanderia wojciki, Nylanderia vividula, and Nylanderia terricola.

Nylanderia concinna workers are morphologically similar to several sympatric species throughout its range in the eastern United States, particularly in Florida. Most similar among these is N. faisonensis, which is also uniform brown with lighter coxae. However, there are several morphological differences that separate the two species: the mesocoxae and metacoxae on N. concinna are medium brown compared to the dark brown body, but those of N. faisonensis are whitish; the scapes of N. concinna are medium brown compared to the yellowish scapes of N. faisonensis; finally, a band of pubescence is found across the anterior edge of the propodeum. Nylanderia wojciki also has whitish mesocoxae and metacoxae, but it is typically bicolored and small (TL: 1.59–2.18). Confusion with N. vividula and N. terricola may also occur, although both those taxa have sparsely pubescence heads, usually are bicolored, and the ocelli are not apparent. In some cases, young workers may have a lighter, yellowish mesosoma, although other features will allow for separation of this species from the bicolored N. wojciki, N. terricola, and N. vividula. Males are similar to N. faisonensis, although those of N. concinna are larger and do not have strongly contrasting mesocoxae and metacoxae.

Distribution
Eastern US.

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

Habitat
marshy areas, in rotten wood, grass tussocks, swamps, and the moist soil of potted plants

Nomenclature

 *  concinna. Paratrechina concinna Trager, 1984b: 88, figs. 11, 14, 41 (w.q.m.) U.S.A. Combination in Nylanderia: LaPolla, Brady & Shattuck, 2010a: 127. See also: Kallal & LaPolla, 2012: 17.

Worker
Kallal & LaPolla (2012) - Measurements (n=15) TL: 1.87–2.77; HW: 0.47–0.64; HL: 0.56–0.72; EL: 0.14–0.21; SL: 0.67–0.86; PW: 0.38–0.48; WL: 0.68–0.93; GL: 0.62–1.23; PH: 0.20–0.31; PFL: 0.50–0.72; PFW: 0.14–0.18. SMC: 7–13; PMC: 2–5; MMC: 2–4. Indices: CI: 85–99; REL: 24–30; SI: 112–129; FI: 87–102.

Overall dark brown in color; mandibles, scapes, mesocoxae, and metacoxae lighter brown; legs often lighter with yellowish joints; cuticle smooth and shiny; cephalic pubescence dense, arising from small depressions; mesosoma pubescence sparse on pronotum, anteriodorsal area of propodeum with band of moderate pubescence; gastral pubescence virtually absent. Head ovate; posterior margin slightly emarginated medially; scapes surpass posterior margin by first 3–4 funicular segments; ocelli apparent. Pronotal anterior face at approximately 45°, with pronotal anterior face shorter than pronotal dorsal face; anterior margin of mesonotum continuous with pronotal margin; propodeum with short dorsal face and long declivitous face.

Queen
Kallal & LaPolla (2012) - Measurements (n=3) TL: 4.14–4.48; HW: 0.81–0.86; HL: 0.82–0.90; EL: 0.28–0.30; SL: 0.88–0.89; PW: 0.88; MW: 0.78–0.84; WL: 1.18–1.61; GL: 1.98–2.09; PH: 0.35–0.49; PFL: 0.81–0.84; PFW: 0.24–0.25. SMC: 3–7; PMC: 3–6; MMC: 8–12; MtMC: 4–6. Indices: CI: 92–104; REL: 33–34; SI: 99–107; FI: 90–102.

Dark brown in color; mandibles and scapes medium brown; leg joints yellowish-brown; cuticle smooth and shiny; densely pubescent, macrosetae brown. Head as broad as it is long; scapes surpass posterior margin by first 3 funicular segments. Propodeum with short, sloped dorsal face and steeply sloped declivitous face.

Male
Kallal & LaPolla (2012) - Measurements (n=6) TL: 2.03–2.35; HW: 0.48–0.62; HL: 0.53–0.66; EL: 0.19–0.26; SL: 0.65–0.72; PW: 0.51–0.53; MW: 0.45–0.51; WL: 0.76–0.96; GL: 0.66–0.85; PH: 0.28–0.34; PFL: 0.53–0.65; PFW: 0.13–0.18; PL: 0.19–0.27. SMC: 2–7; MMC: 5–12; MtMC: 2–4. Indices: CI: 91–98; REL: 36–40; SI: 103–121; FI: 94–101.

Overall dark brown in color; joints of legs and tarsi yellowish; cuticle smooth and shiny; cephalic pubescence dense; mesosoma with pubescence densest on mesonotum, with some patches on katepisternum; gastral pubescence virtually absent anteriorly becoming sparse posteriorly; macrosetae brown. Head as broad as it is long; eyes weakly convex, scarcely extending beyond 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 large apical tooth plus a smaller subapical tooth. Mesosoma enlarged to accommodate flight muscles; in lateral view, pronotal margin short and relatively straight, with raised patches towards mesonotal margin; propodeum with sloped dorsal face, distinctly longer than declivitous face. Genitalia: parameres laterally oriented, triangular; digitus angled ventrally, about as long as aedeagal valves, with cuspides about half as long, both with rounded teeth where they meet; aedeagal valves triangular, teeth absent; ninth sternite triangular with short, rounded, broad lateral apodemes and broad ventral apodeme.

Additional References

 * Kallal, R.J. & LaPolla, J.S. 2012. Monograph of Nylanderia (Hymenoptera: Formicidae) of the World, Part II: Nylanderia in the Nearctic. Zootaxa 3508, 1-64.