Turneria bidentata

Turneria bidentata occurs in the Top End of the Northern Territory and along the east Australian coast from the Cape York Peninsula to extreme north-eastern New South Wales. It is a twig-nesting species that is reasonably common although it is infrequently encountered because of its arboreal nesting habits. It is known to nest in a wide range of tree and shrub species.

Identification
Cephalic index (head length/head width) < 0.88, relative eye length (eye length/head width) > 0.40, frontal lobes without erect hairs, lateral areas of head moderately imbricate and with integument opaque, area between propodeal protuberances concave. In lateral profile, the concave region of the declivitous face of the propodeum is more rounded than in other species.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  bidentata. Turneria bidentata Forel, 1895f: 419 (w.) AUSTRALIA. Shattuck, 1990: 108 (q.m.).

Lectotype worker (lower specimen on pin) from Mackay, Queensland, Australia (M. G. Turner), designated by Shattuck (1990); one paralectotype on same pin as lectotype.

Description
The clypeus possesses 8 to 14 erect hairs. Color varies from uniform dark brown or black to strongly bicolored with the head, alitrunk, legs and petiole yellow and the gaster brown. In lighter colored individuals, the dorsum of the head may be slightly darker than the mesosoma.

Worker measurements (n=25): OOD 0.15-0.21, EL 0.24-0.28, OCD 0.10-0.13, CL 0.13-0.19, HL 0.65-0.75, LES 0.03-0.05, EW 0.11-0.15, ES 0.24-0.28, HW 0.55-0.66, SL 0.41-0.46, PnL 0.30-0.42, ML 0.27-0.37, PpL 0.23-0.30, PnW 0.36-0.43, MW 0.23-0.30, PpW 0.25-0.29, PO -0.01-0.04, FFL 0.41-0.53, FFW 0.16-0.21, MH 0.31-0.39, PpH 0.22-0.29, CI 0.80-0.88, OI 0.43-0.57, REL 0.40-0.48, SI 0.70-0.79, FI 0.34-0.48, PI 0.63-0.71, PpI 0.87-1.10, ROOD 0.28-0.33, POI -0.04-0.17, RPO -0.02-0.07, RMW 0.42-0.47, RLES 0.05-0.09, RES 0.41-0.45, RFFL 0.66-0.94.

Body color in this species is highly variable. Populations from the vicinity of Cairns are uniform dark brown, Mackay-area populations are strongly bicolored, while southern collections from Burleigh Heads are yellowish brown with the gaster slightly darker; in extreme cases some workers are yellow-brown with a black gaster. None of these populations diverge in any of other morphological traits, although the Cairns-vicinity specimens average slightly, but insignificantly, smaller. For most traits all known specimens broadly overlap. The Cairns-vicinity populations diverge slightly from the more southern ones in two metric traits, MW and PpH, as follows: MW 0.23-0.27 vs. 0.25-0.30 and PpH 0.22-0.25 vs. 0.23-0.29. The broad overlap in the ranges of these characters make them of little value in separating these populations.

The convexity of the area between the propodeal spiracles (when viewed dorsally), a character used to separate this species from the Papua New Guinea-based T. arbusta by Shattuck (1990), is now known to vary more than originally thought, being less concave in some specimens, especially those from the Northern Territory (Shattuck 2011). However, this region is still concave and the separation from T. arbusta is supported by this character as well as differences in head shape (more elongate in T. bidentata and broader in T. arbusta) and scape length (averaging shorter in T. bidentata, longer in T. arbusta). Together, these characters suggest that these species are distinct and both are best regarded as valid species.

Definitions of measurements cited above
 * CL: Clypeal Length: measured in full face view.
 * CI: Cephalic index: HL/HW.
 * EL: Eye Length: measured in full face view.
 * ES: Eye Spread: distance between inner-most edges of eyes measured in full face view.
 * EW: Eye width measured in full face view.
 * FFL: Fore Femur Length: maximum length of fore femur measured in lateral view.
 * FFW: Fore Femur Width: maximum width of fore femur measured in lateral view.
 * FI: Femur Index: FFW/FFL.
 * HL: Head Length: maximum length of head in full face view, from the anterior clypeal margin to the midpoint of a line drawn across the occipital margin.
 * HW: Head Width: maximum width of head in full face view, excluding eyes in workers and queens, including eyes in males.
 * LES: Lateral Eye Space: distance from lateral edge of head to lateral edge of eye measured in full face view.
 * MH: Mesothoracic Height: maximum height of the mesothorax measured perpendicular to the measuring axis.
 * ML: Mesonotal Length: distance from the pronotal-mesonotal suture to the metanotal groove measured parallel to the measuring axis.
 * MW: Mesonotal Width: minimum width of mesonotum in dorsal view profile.
 * OCD: Ocular-Clypeal Distance: distance between anterior margin of eye and posterior margin of clypeus measured in full face view.
 * OI: Ocular Index: EW/EL.
 * OOD: Occiput-Ocular Distance: distance between posterior margin of eye and posterior extremity of occipital border measured in full face view.
 * PI: Pronotal Width Index: PnW/HW.
 * PnL: Pronotal Length: distance from the anterior edge of the pronotal collar to the pronotal-mesonotal suture measured parallel to the measuring axis.
 * PnW: Pronotal Width: maximum width of pronotum, measured in dorsal view.
 * PO: Propodeal Overhang: distance from the posterior-most point of the propodeal tubercles to the posterior-most point of the petiolar insertion measured parallel to the measuring axis.
 * POI: Propodeal Overhang Index: PO/PpH.
 * PpH: Propodeal Height: maximum height of the propodeum measured perpendicular to the measuring axis.
 * PpL: Propodeal Length: distance from the metanotal groove to the posterior-most point of the propodeal tubercles measured parallel to the measuring axis.
 * PpI: Propodeal Length Index: PpL/HW.
 * PpW: Propodeal Width: maximum width of the dorsal propodeal surface in dorsal view.
 * REL: Relative Eye Length: EL/HW.
 * RFFL: Relative Fore Femur Length: FFL/HW.
 * RES: Relative Eye Spread: ES/HW.
 * RLES: Relative Lateral Eye Space: LES/HW.
 * RMW: Relative Mesonotal Width: MW/HW.
 * ROOD: Relative Occiput-Ocular Distance: OOD/HW.
 * RPO: Relative Propodeal Overhang: PO/HW.
 * SI: Scape index: SL/HW.
 * SL: Scape Length: length of the first antennal segment (scape) excluding the basal radicle.

Additional References

 * [[Media:Shattuck 1990.pdf|Shattuck, S. O. 1990. Revision of the dolichoderine ant genus Turneria (Hymenoptera: Formicidae). Syst. Entomol. 15: 101-117 PDF]]


 * Shattuck, S.O. (2011) Turneria rosschinga sp.n. (Hymenoptera: Formicidae), a new dolichoderine ant from Australia. Myrmecological News 15, 125-128.