Nylanderia arenivaga

This nocturnal species is commonly found in open, yellow sand areas in the eastern United States from Massachusetts to Florida, with some collections to the west along the Gulf States (Kallal & LaPolla, 2012).

Identification
Kallal & LaPolla (2012) - Overall coloration yellow; gaster distally becomes brown; macrosetae dense, particularly on gaster. Compare with: Nylanderia phantasma and Nylanderia querna.

This species may be differentiated from N. phantasma based on their darker yellow coloration, dark tip of the gaster, presence of brown macrosetae on the mesosoma and gaster, and brown (not reddish) teeth. In Georgia and Florida, where both species are known to occur sympatrically, N. arenivaga is more common on yellow sands while N. phantasma is found on white (M. Deyrup, pers. comm.). The worker of this species is very similar in color to Nylanderia querna. The presence of a darker posterior region of the gaster and macrosetae pattern noted above distinguish N. arenivaga from N. querna. Nylanderia arenivaga has long, slender digiti and cuspides that are shared only with N. phantasma', whereas N. querna has shorter digiti and cuspides that are more similar to species such as Nylanderia parvula and Nylanderia faisonensis.

Distribution
Eastern US, Massachusetts to Florida, Gulf coast states.

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

Habitat
Open sandy areas.

Biology
Kallal & LaPolla (2012) - Nylanderia arenivaga nests are greater than 20–30 cm deep (Trager, 1984). Numerous flat crater nests 4–7 cm in diameter clustered in one area suggest either polydomy or many neighboring colonies (Wheeler, 1905; Thompson, 1988). Up to 20 entrances may be shared by one nest (Trager, 1984). Alates have been observed in January, July, and August, with flights occurring in January through April, with later flights in the northern portion of their range (Trager, 1984). Workers are observed to forage all winter long in southern portions of their range (Trager, 1984).

Several other arthropods are known to have associations with N. arenivaga. The planthopper Oecleus borealis and Myrmecophila crickets have both been recorded in association N. arenivaga, the former possibly benefiting from ant tunneling to reach roots to feed (Thompson 1984). Recently, the phorid fly Pseudacteon gracilisetus was discovered and described. These flies were seen “dive-bombing” workers presumably to parasitize them (Brown et al., 2011).

Nomenclature

 *  arenivaga. Prenolepis arenivaga Wheeler, W.M. 1905f: 391, fig. 3 (w.m.) U.S.A. Kallal & LaPolla, 2012: 10 (q.). Combination in Pr. (Nylanderia): Forel, 1922: 98; in Paratrechina (Nylanderia): Emery, 1925b: 221; in Nylanderia: LaPolla, Brady & Shattuck, 2010a: 127. Subspecies of melanderi: Creighton, 1950a: 408. Revived status as species: Trager, 1984b: 119.

Worker
Kallal & LaPolla (2012) - Measurements (n=21): TL: 1.84–2.63; HW: 0.43–0.64; HL: 0.54–0.70; EL: 0.13–0.19; SL: 0.55–0.78; PW: 0.33–0.44; WL: 0.63–0.87; GL: 0.63–1.18; PH: 0.17–0.27; PFL: 0.46–0.69; PFW: 0.11-0.19.SMC: 1–12; PMC: 2–7; MMC: 1–4. Indices: CI: 78–99; REL: 23–30; SI: 98–123; FI: 81–126.

Overall yellow; head slightly darker, mandibles with brownish teeth, mesocoxae and metacoxae same color as mesosoma; posterior region of gaster brownish; cuticle smooth and shiny; cephalic pubescence dense; mesosoma and gastral pubescence virtually absent; macrosetae particularly numerous on gaster. Head ovate; posterior margin slightly emarginated medially; scapes surpass posterior margin by about the length of first 3–4 funicular segments; ocelli not apparent. Pronotal anterior face approximately 45°; pronotum inflected weakly with pronotal anterior face shorter than pronotal dorsal face; anterior margin of mesonotum continuous with posterior pronotal margin; propodeum low with a rounded dorsal face descending smoothly into shorter declivitous face.

Queen
Kallal & LaPolla (2012) - Measurements (n=4) TL: 4.20–4.67; HW: 0.64–0.90; HL: 0.85–1.01; EL: 0.27–0.31; SL: 0.86–0.95; PW: 1.00–1.18; MW: 0.93–1.05; WL: 1.45–1.59; GL: 1.88–2.15; PH: 0.47–0.57; PFL: 0.81–0.96; PFW: 0.21–0.28. SMC: 3–7; PMC: 3–10; MMC: 10–25; MtMC: 3–7. Indices: CI: 74–99; REL: 29–33; SI: 94–110; FI: 88–111.

Overall yellow with darker, yellow-brown portions of mesosoma and gaster; generally darker coloration than in worker; cuticle smooth and shiny; dense pubescence covers entire body; pubescence yellow, macrosetae yellowish-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 longer declivitous face.

Male
Kallal & LaPolla (2012) - Measurements (n=8): TL: 1.77–2.26; HW: 0.46–0.53; HL: 0.47–0.56; EL: 0.18–0.22; SL: 0.51–0.64; PW: 0.46–0.58; MW: 0.41–0.56; WL: 0.58–0.79; GL: 0.64–0.89; PH: 0.18–0.37; PFL: 0.47–0.64; PFW: 0.10–0.14; PL: 0.21–0.30. SMC: 0–5; MMC: 3–12; MtMC: 2–5. Indices: CI: 94–104; REL: 38–48; SI: 101–116; FI: 97–120.

Overall brown, with distal segments of legs, mandibles, and antennae yellowish; gaster often darker brown than remainder of body; cuticle smooth and shiny in areas not obscured by pubescence; cephalic pubescence moderate; mesonotum with dense pubescence; gastral pubescence virtually absent. Head as broad as long; eyes convex, extending well beyond lateral margin of head in full face view; scapes surpass posterior margin by first 2–4 funicular segments; mandible with long, straight inner mandibular margin, a basal angle at approximately 90°, and a smooth masticatory margin with a single, large apical tooth. Mesosoma enlarged to accommodate flight muscles; in lateral view, pronotal margin short and straight; propodeum with steep dorsal face slightly longer than the declivitous face. Genitalia: parameres laterally oriented, long, triangular, and curved slightly inward; digiti and cuspides elongate, slightly curved toward each other, with rounded, peg-like teeth present on the surfaces where they meet; cuspides broadly rounded distally; aedeagal valves triangular, tapered slightly distally, teeth absent; ninth sternite broad with short, blunt lateral apodemes and short medial 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.