Nylanderia terricola

Nylanderia terricola is characteristic of prairies (Trager 1998, Phipps 2006, Nemec et al. 2012), although it has also been collected from a variety of habitats from open disturbed areas to mesquite and woodlands (Trager 1984). It is found in most soil types, except very sandy soils, and nests under stones, logs, or cow dung (Trager 1984). Nests may also be found in open grassy areas. Reproductives fly in spring and early summer. (Kallal & LaPolla, 2012).

Identification
Kallal & LaPolla (2012) - Bicolored with head and gaster darker than mesosoma and legs; sparse pubescence on head; head oval in shape.

Compare with: Nylanderia austroccidua, Nylanderia concinna, Nylanderia flavipes and Nylanderia vividula.

Nylanderia terricola and N. vividula workers are virtually impossible to reliably separate from each other based on morphology. Males are distinctive and can be used to separate these two species. Distinguishing these two taxa, along with other similar species to N. vividula, are discussed in the identification section for N. vividula.

Identification Keys including this Taxon

 * Key to Nearctic Nylanderia workers
 * Key to Nearctic Nylanderia males

Distribution
This species has perhaps the widest range in the Nearctic, ranging across practically the entire United States and much of northern and central Mexico (Kallal & LaPolla, 2012).

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

Biology
Roeder et al. (2018) in an Oklahoma study found the CTmax (critical thermal maximum) for this species was 46.7 ± 0.2 C and the average worker mass was 0.078 ± 0.004 mg.

In New Mexico (Mackay and Mackay 2002) - Occurs in open disturbed areas, grasslands, mesquite shrubland, pinyon woodland, sagebrush (1770m elevation), post-oak woodlands, areas adjacent to forests, or even in dense, mesic woodlands. This species nests under stones, logs or cow dung, or in the soil. Alates overwinter in the nest, and fly early in the spring.

Nomenclature

 *  terricola. Formica (Tapinoma) terricola Buckley, 1866: 168 (w.q.m.) U.S.A. Combination in Prenolepis: Mayr, 1876: 78; in Paratrechina: Emery, 1925b: 223; in Nylanderia: LaPolla, Brady & Shattuck, 2010a: 127. Junior synonym of vividula: Mayr, 1876: 78; Smith, M.R. 1951a: 849. Revived from synonymy and senior synonym of melanderi: Trager, 1984b: 81. See also: Kallal & LaPolla, 2012: 33.
 * melanderi. Prenolepis melanderi Wheeler, W.M. 1903b: 104, fig. 8 (w.q.m.) U.S.A. Wheeler, G.C. & Wheeler, J. 1953c: 144 (l.). Combination in Pr. (Nylanderia): Emery, 1914f: 422; in Paratrechina (Nylanderia): Emery, 1925b: 223. Subspecies of vividula: Smith, M.R. 1951a: 849. Junior synonym of terricola: Trager, 1984b: 81.

Worker
Kallal & LaPolla (2012) - Measurements (n=30) TL: 1.96–2.63; HW: 0.46–0.57; HL: 0.55–0.67; EL: 0.12–0.18; SL: 0.60–0.75; PW: 0.34–0.43; WL: 0.61–0.89; GL: 0.71–1.26; PH: 0.16–0.29; PFL: 0.45–0.61; PFW: 0.11–0.19. SMC: 5–10; PMC: 1–6; MMC: 1–4. Indices: CI: 77–96; REL; 20–28: SI: 102–118; FI: 75–95.

Bicolored yellowish-brown to dark brown, with head and gaster slightly darker in color; scapes, mandibles, and legs as light or slightly lighter than mesosoma; mesocoxae and metacoxae variably colored as mesosoma to contrastingly pale whitish; cuticle smooth and shiny; cephalic pubescence sparse to absent, becoming denser towards the posterior margin; mesosoma and gastral pubescence virtually absent. Head relatively ovate; posterior margin slightly emarginated medially; scapes surpass posterior margins by first 3–4 funicular segments; ocelli not apparent. Pronotal anterior face at approximately 45°; pronotum inflected with pronotal anterior face slightly shorter than pronotal dorsal face; anterior margin of mesonotum continuous with, or slightly higher than, pronotal margin; propodeum rounded with shorter dorsal face and longer declivitous face.

Queen
Kallal & LaPolla (2012) - Measurements (n=3) TL: 3.83–4.58; HW: 0.73–0.81; HL: 0.77–0.81; EL: 0.24–0.26; SL: 0.77–0.86; PW: 0.76–0.99; MW: 0.74–0.82; WL: 1.29–1.31; GL: 1.75–2.49; PH: 0.40–0.45; PFL: 0.74–0.85; PFW: 0.20–0.23. SMC: 3–7; PMC: 7–9; MMC: 11–14; MtMC: 2–6. Indices: CI: 95–105; REL: 32; SI: 100–107; FI: 95–106.

Yellowish-brown to brown in color, with scapes, mandibles, and leg joints lighter in color; mesosoma sometimes lighter brown than head and gaster; cuticle smooth and shiny; body with dense pubescence; macrosetae brown. Head as broad as it is long; scapes surpass posterior margins by first 3–4 segments. Propodeum with short dorsal face and long, convex declivitous face.

Male
Kallal & LaPolla (2012) - Measurements (n=2) TL: 2.07–2.20; HW: 0.48–0.51; HL: 0.53–0.53; EL: 0.18–0.22; SL: 0.57–0.61; PW: 0.50–0.51; MW: 0.45–0.48; WL: 0.67–0.70; GL: 0.84–1.00; PH: 0.21–0.28; PFL: 0.55–0.59; PFW: 0.14–0.17; PL: 0.25–0.30. SMC: 4–6; MMC: 6–8; MtMC: 2. Indices: CI: 91–95; REL: 34–42; SI: 108–115; FI: 103–111.

Overall brown in color, with scapes, mandibles, and leg joints yellowish-brown; mesocoxae and metacoxae sometimes lighter; cuticle smooth and shiny; cephalic pubescence sparse; mesosoma pubescent dorsally, except for pronotum; gastral pubescence virtually absent; macrosetae brown. Head slightly longer than broad; eyes convex, extending beyond the lateral margins of the head in full face view; antennae bent around segment IV; scapes surpass posterior margin by 3–4 segments; inner mandibular margin long and straight; basal angle approximately 90°; masticatory margin with one subapical tooth and large apical tooth, sometimes with additional denticles, appearing scalloped. Mesosoma enlarged to accommodate flight muscles; in lateral view, pronotal margin short and straight, or sometimes angled at around 45° then inflected vertically; propodeum with equally long dorsal and declivitous faces. Genitalia: parameres laterally oriented, triangular, becoming digitiform distally; digiti curved, tapering, then ending in a broadened tip; cuspides short and rounded apically with small teeth; aedeagal valves triangular with similar termini as digiti, teeth absent; ninth sternite with short, pointed lateral apodemes and relatively large, broad ventral apodeme.