Nylanderia hystrix

Nylanderia hystrix nests are commonly found under stones in desert washes. Reproductive flights are not known for this species, although it is suspected they follow the pattern of other Nearctic species (Trager, 1984). it apparently does not occur sympatrically with Nylanderia bruesii in the Sonoran Desert.

Identification
Kallal & LaPolla (2012) - Uniformly yellow with numerous strongly contrasting black macrosetae. This desert species has a very distinctive appearance. Being a large, uniformly yellow species with strikingly contrasting black macrosetae all over its body, it cannot easily be confused with any other Nearctic Nylanderia species.

Distribution
This species is known from the Mojave and Great Basin deserts.

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

Habitat
They can be found at elevations between 500 and 1500 m. Habitats in which they have been collected range from creosote-sagebrush deserts to pine-juniper woodlands (Trager, 1984).

Nomenclature

 *  hystrix. Paratrechina hystrix Trager, 1984b: 134, figs. 28, 30, 40 (w.q.m.) U.S.A. Combination in Nylanderia: LaPolla, Brady & Shattuck, 2010a: 127. See also: Kallal & LaPolla, 2012: 23.

Worker
Kallal & LaPolla (2012) - Measurements (n=10) TL: 2.51–3.10; HW: 0.56–0.66; HL: 0.68–0.82; EL: 0.15–0.19; SL: 0.81–1.05; PW: 0.40–0.49; WL: 0.82–1.13; GL: 0.87–1.21; PH: 0.22–0.31; PFL: 0.68–0.76; PFW: 0.13–0.18. SMC: 10–29; PMC: 8–16; MMC: 4–10. Indices: CI: 80–87; REL: 21–25; SI: 119–132; FI: 91–103.

Overall uniformly yellow to brownish yellow in color; mesocoxae and metacoxae same color as mesosoma; cuticle smooth and shiny; cephalic pubescence sparse; mesosoma and gastral pubescence virtually absent; macrosetae black, contrasting strongly with cuticle color; macrosetae numerous on head, mesosoma, and gaster. Head ovate; posterior margin emarginated medially; scapes surpass posterior margin by first 3–4 funicular segments; ocelli apparent. Pronotal anterior face approximately 45° or less; pronotum inflected with pronotal anterior face shorter than pronotal dorsal face; anterior margin of mesonotum continuous with pronotal margin; propodeum with dome-like dorsal face and long declivitous face.

Queen
Kallal & LaPolla (2012) - Measurements (n=1) TL: 4.37; HW: 0.82; HL: 0.91; EL: 0.23; SL: 1.03; PW: 0.78; MW: 0.72; WL: 1.50; GL: 1.95; PH: 0.39; PFL: 0.88; PFW: 0.19. SMC: 26; PMC: 17; MMC: 12; MtMC: 4. Indices: CI: 90; REL: 25; SI: 112; FI: 97.

Uniform yellow to brownish yellow in color; cuticle smooth and shiny; body with dense pubescence; macrosetae black and numerous. Head nearly as broad as it is long; median ridge on clypeus; posterior margin with shallow medial emargination; scapes surpass posterior margin by first 3 funicular segments. Propodeum with very short dorsal face and long declivitous face.

Male
Kallal & LaPolla (2012) - Measurements (n=4) TL: 2.35–2.58; HW: 0.51–0.55; HL: 0.57–0.60; EL: 0.18–0.19; SL: 0.71–0.83; PW: 0.53–0.58; MW: 0.45–0.52; WL: 0.84–0.94; GL: 0.85–1.04; PH: 0.23–0.33; PFL: 0.62–0.70; PFW: 0.12–0.14; PL: 0.24–0.26. SMC: 15–35; MMC: 8–18; MtMC: 3–6. Indices: CI: 86–91; REL: 31–33; SI: 120–145; FI: 106–117.

Yellowish-brown with dark brown gaster; mandibles, scapes, legs, and parameres brownish yellow; cuticle smooth and shiny; cephalic pubescence sparse; mesosoma and gastral pubescence absent; macrosetae black and numerous. Head longer than it is broad; eyes convex, extending beyond lateral margins of the head in full face view; scapes surpass posterior margin by first 4–5 funicular segments; inner mandibular margin long and straight; basal angle approximately 90°; smooth masticatory margin with large apical tooth. Mesosoma enlarged to accommodate flight muscles; in lateral view, pronotal margin short and relatively straight with slight inflection towards mesonotal margin; propodeum with dorsal and declivitous faces of approximately equal lengths. Genitalia: parameres laterally oriented, triangular; digitus slightly longer than parameres, as long as aedeagal valves, angled ventrally; cuspis about half as long; both structures with rounded teeth where they meet; aedeagal valves with thickened distal tips, teeth absent; ninth sternite very long and broad with very reduced lateral apodemes and very short 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.