Froggattella kirbii

Collections of F. kirbii are from drier sclerophyll woodland areas (including mallee), and it is not known from wet sclerophyll woodlands or rainforests. Specimens are most often encountered as foragers on tree trunks or low vegetation although they commonly forage on the ground. All known nests have been found in rotten wood above the ground, usually in a stump or dead branch on a living tree.

Identification
Sculpturing weakly developed and uniform over the entire upper surface of the head, varying only slightly between the anterior and posterior regions; rugae on the mesopleuron well developed and superimposed on top of the underlying sculpturing, individual rugae are more or less straight and are not influenced by the underlying punctations or reticulations; posterior region of the propodeal spines in dorsal view with their outer surfaces concave.

Distribution
This taxon was described from Australia.

Biogeographically, F. kirbii occurs in four distinct, disjunct regions: (i) south-eastern Australia, (ii) south-western Western Australia, (iii) coastal northern Queensland, and (iv) the Darwin and Kimberley regions. Its absence from the areas between south-eastern Australia and south-western Western Australia (the Nullarbor Plain), and between northern Queensland and the Darwin region (the Gulf Country) is not unexpected. These intermediate areas have significantly different climates and vegetation types than the neighbouring regions and thus may not provide suitable habitat for Froggattella. Additionally, several other ant genera show similar distribution patterns in these areas, including Acropyga, Anochetus, Hypoponera, Podomyrma and Solenopsis.

The remaining disjunction, between northern and southern coastal Queensland, is also shared with numerous other ant taxa, including Carebara, Cryptopone, Discothyrea, Epopostruma, Heteroponera, Lordomyrma, Metapone, Myopias, Myrmecina, Notostigma, Prionopelta and Pristomyrmex. The cause for the absence (or scarcity) of F. kirbii between approximately Townsville and Rockhampton is apparently climatic. This region has a lower annual mean rainfall (< 1200mm) and rainfall is more variable than the area occupied by the northern population of F. kirbii (> 1600mm), and has higher mean temperatures than areas occupied by the south-eastern populations (AUSLIG, 1986). Additionally, grasslands make up a much higher proportion of the habitats in this region when compared to areas further north and south where F. kirbii is more common (AUSLIG, 1990). It seems probable that low, unpredictable rainfall and high temperatures have combined with reduced suitable habitat (woodlands replaced by grasslands) to limit the occurrence of Froggattella in this area. At the same time, it is likely that F. kirbii (and perhaps other taxa showing a similar pattern) do occur in this region but are limited to small patches of suitable habitat. This seems especially likely for species which occur on both sides of this disjunction, but less likely in genera where distinct species occur across this gap.

Nomenclature

 *  kirbii. Acantholepis kirbii Lowne, 1865b: 333 (w.) AUSTRALIA. Wheeler, W.M. 1936a: 6 (q.m.); Wheeler, G.C. & Wheeler, J. 1951: 182 (l.). Combination in Hypoclinea: Mayr, 1870b: 954; in Dolichoderus: Dalla Torre, 1893: 159; Emery, 1894c: 228; in Froggattella: Forel, 1902h: 459. [Unjustified emendation of spelling to kirbyi: Mayr, 1876: 80; Forel, 1902h: 459.] See also: Wheeler, G.C. & Wheeler, J. 1966: 728. Senior synonym of: bispinosa, ianthina, laticeps, lutescens, nigripes: Shattuck, 1996b: 45.
 * bispinosa. Froggattella kirbyi var. bispinosa Forel, 1902h: 460 (w.) AUSTRALIA. Junior synonym of kirbii: Shattuck, 1996b: 45.
 * ianthina. Froggattella kirbyi subsp. ianthina Wheeler, W.M. 1936a: 8 (w.) AUSTRALIA. Junior synonym of kirbii: Shattuck, 1996b: 45.
 * laticeps. Froggattella kirbyi subsp. laticeps Wheeler, W.M. 1936a: 10 (w.) AUSTRALIA. Junior synonym of kirbii: Shattuck, 1996b: 45.
 * lutescens. Froggattella kirbyi subsp. lutescens Wheeler, W.M. 1936a: 9 (w.) AUSTRALIA. Junior synonym of kirbii: Shattuck, 1996b: 45.
 * nigripes. Froggattella kirbyi subsp. nigripes Wheeler, W.M. 1936a: 8 (w.) AUSTRALIA. Junior synonym of kirbii: Shattuck, 1996b: 45.

Description
Froggattella kirbii shows considerable variation in size. Although this variation occurs primarily between nest series (i.e. all members of a given nest series are similar in size), it is continuous between the smallest and largest and occurs throughout the range of the species. Thus while this variation appears to have a genetic component, its variability and presence in all populations of F. kirbii suggests that only a single species is involved. In addition, no evidence could be found to suggest that more than one species is present as all specimens share an overall similarity in most morphological characters, including sculpturing, colour, pilosity and general habitus (including the shape of the head, mesosoma and petiole).

Measurements Worker (n = 11) - CI 0.91-0.96; EL 0.15-0.22; EW 0.09-0.12; HL 0.69-0.95; HTL 0.55-0.75; HW 0.66-0.91; ML 0.26-0.39; PnL 0.41-0.63; PpL 0.30-0.47; SI 0.71-0.76; SL 0.46-0.65.

CI: cephalic index: HW/HL. EL: maximum eye length measured in full face view. EW: maximum eye width measured in full face view. HL: maximum head length in full face view, measured from the anterior-most point of the clypeal margin to the midpoint of a line drawn across the posterior margin of the head. HTL: maximum length of hind tibia, excluding the proximal part of the articulation which is received into the distal end of the hind femur. HW: maximum head width in full face view, excluding eyes. ML: mesonotal length measured from the pronotal-mesonotal suture to the metanotal groove parallel to the measuring axis. PnL: pronotal length measured from the anterior edge of the pronotal collar to the pronotal-mesonotal suture parallel to the measuring axis. PpL: propodeal length measured from the metanotal groove to the posterior-most point of the petiolar insertion parallel to the measuring axis. SI: scape index: SL/HW. SL: length of the scape (first antennal segment) excluding the basal radicle.

Additional References

 * Fraser, A. M., Tregenza, T.,Wedell, N., Elgar, M. A., Pierce, N. E. (2002). Oviposition tests of ant preference in a myrmecophilous butterfly . Journal of Evolutionary Biology. 15: 861–870 [association with Lepidoptera].
 * [[Media:Shattuck 1996b.pdf|Shattuck, S. O. 1996b. The Australian ant genus Froggattella (Hymenoptera: Formicidae) revisited. Aust. J. Entomol. 35: 43-47 PDF]]