Nylanderia parvula

Nests often occur in open areas, especially at forest edges and under stones (Trager, 1984). In the northeastern United States, they are particularly common in sandy substrates where small craters mark their nests, with much of their nest near the surface. Chambers have been found up to 30 cm below the surface (Trager, 1984). Reproductives are reared in mid summer in the north and late summer in the south, which then overwinter and fly the following spring (Trager, 1984) (Kallal & LaPolla, 2012).

Identification
Kallal & LaPolla (2012) - Small (TL: 1.6–2.2); uniformly dark brown to black in color; scape macrosetae absent.

Compare with: Nylanderia trageri and Nylanderia wojciki.

Nylanderia parvula is one of only two species in the Nearctic that lacks scape macrosetae in the worker caste. The other is N. trageri, which is yellow. While some western populations of N. parvula are lighter than eastern populations they are always brown to darker in coloration, never being yellow as is observed in N. trageri.

Distribution
Eastern US.

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

Biology
Nylanderia parvula can be found in nearly every state in the eastern half the United States. They are among the most common ants in the sandy, moist pine barrens of the Northeast, the mixed deciduous forests of the Great Smoky Mountains, and sandy pine-oak dune woodlands of the Southeast. This species is found the furthest north of any Nylanderia species in the Nearctic, occurring into Ontario, Canada. An undescribed socially parasitic Nylanderia species (n. sp. 2) is known to parasitize N. parvula populations in Massachusetts (Cover et al., in prep) (Kallal & LaPolla, 2012).

Nomenclature

 *  parvula. Prenolepis parvula Mayr, 1870b: 948 (w.q.m.) U.S.A. Wheeler, G.C. & Wheeler, J. 1968: 211 (l.). Combination in Pr. (Nylanderia): Forel, 1922: 98; in Paratrechina (Nylanderia): Emery, 1925b: 222; in Nylanderia: LaPolla, Brady & Shattuck, 2010a: 127. Subspecies of vividula: Forel, 1885a: 348; Mayr, 1886d: 431. Revived status as species: Emery, 1893i: 636. See also: Trager, 1984b: 104; Kallal & LaPolla, 2012: 27.

Worker
Kallal & LaPolla (2012) - Measurements (n=15) TL: 1.63–2.31; HW: 0.43–0.56; HL: 0.515–0.64; EL: 0.14–0.17; SL: 0.47–0.67; PW: 0.22–0.41; WL: 0.57–0.76; GL: 0.50–0.92; PH: 0.16–0.30; PFL: 0.45–0.52; PFW: 0.12–0.19. SMC: 0; PMC: 2–5; MMC: 2–3. Indices: CI: 78–90; REL: 24–30; SI: 84–118; FI: 80–95.

Dark brown in color; antennae and mandibles distinctly lighter, often grayish yellow; leg joints yellowish, especially tarsi; mesocoxae and metacoxae infrequently less dark than mesosoma; cuticle smooth and shiny; cephalic pubescence moderate; mesosoma and gastral pubescence virtually absent. Head ovate; posterior margin slightly emarginated medially; scapes surpass posterior margin by first 2–3 funicular segments; ocelli not apparent. Pronotal anterior face at least 45°; pronotum weakly inflected with approximately equally long pronotal anterior and pronotal dorsal faces; anterior margin mesonotum continuous with, or slightly higher than, pronotal margin; propodeum gently rounded with declivitous face slightly longer than the dorsal face.

Queen
Kallal & LaPolla (2012) - Measurements (n=4) TL: 3.31–4.84; HW: 0.68–0.83; HL: 0.73–0.82; EL: 0.24–0.26; SL: 0.77–0.81; PW: 0.80–0.93; MW: 0.76–0.86; WL: 1.15–1.41; GL: 1.31–2.62; PH: 0.41–0.51; PFL: 0.63–0.80; PFW: 0.21–0.22. SMC: 0; PMC: 3–6; MMC: 8–20; MtMC: 3–5. Indices: CI: 92–104; REL: 31–35; SI: 96–111; FI: 83–110.

Dark brown to nearly black in color; scapes and mandibles lighter brown; leg joints and tarsi yellowish-brown; cuticle smooth and shiny; body with dense pubescence; macrosetae brown. Head as broad as it is long; scapes surpass posterior margin by first 3–4 funicular segments. Propodeum with short, sloped dorsal face and steeply sloped declivitous face.

Male
Kallal & LaPolla (2012) - Measurements (n=4) TL: 1.75–2.35; HW: 0.48–0.54; HL: 0.48–0.59; EL: 0.20–0.22; SL: 0.50–0.66; PW: 0.44–0.61; MW: 0.34–0.50; WL: 0.65–0.80; GL: 0.62–0.98; PH: 0.22–0.32; PFL: 0.45–0.56; PFW: 0.13–0.16; PL: 0.19–0.24. SMC: 0; MMC: 3–9; MtMC: 2. Indices: CI: 89–100; REL: 36–42; SI: 100–115; FI: 81–99.

Overall brown with yellowish-brown scapes and legs; gaster often slightly darker brown; cuticle smooth and shiny; cephalic pubescence moderate to dense; mesonotum with dense pubescence; gastral pubescence virtually absent. Head slightly longer than broad; eyes weakly convex, scarcely extending beyond lateral margins of the head in full face view; scapes surpass posterior margin by first 3–4 segments; mandible with long, straight inner mandibular margin; basal angle of approximately 90°; and a smooth masticatory margin large apical tooth and smaller subapical tooth. Mesosoma enlarged to accommodate flight muscles; in lateral view, pronotal margin short and relatively straight; propodeum with long, sloped dorsal face and shorter, nearly vertical declivitous face. Genitalia: parameres laterally oriented, short, triangular; digiti and cuspides as in faisonensis and concinna, but overall shorter, particular the cuspides; aedeagal valves triangular, with small notch toward the base of the ventral edge, teeth absent; ninth sternite with moderately long ventral apodeme and short, blunt lateral apodemes.

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.