Aphaenogaster balcanica

On Lesbos observed in open, sunny locations: fields with scattered shrubs and urban areas. Nest in soil, mostly sheltered by stones. Workers are individually foraging on the ground, in herbs and bases of trees and shrubs. Foraging behavior can be described as cautious. Fast moving after disturbance. Evacuation of the nest population is observed after heavy rainfall. (Boer 2013)

Identification
A member of the A. testaceopilosa group. Boer (2013) - Workers. Similar to Aphaenogaster balcanicoides and Aphaenogaster melitensis. Aphaenogaster balcanicoides and A. melitensis are more setose on the petioles and have shorter setae. The SI/CI and the PPPI are significantly lower than in A. karpathica (p < 0.01), the RPH is significantly higher than in A. balcanicoides (p < 0.04), and lower than in A. melitensis (p < 0.01). Gynes. Punctation stronger than in A. melitensis.


 * Key to European Aphaenogaster workers

Distribution based on Regional Taxon Lists
Palaearctic Region: Albania, Bosnia and Herzegovina, Croatia, Greece, Italy , Malta, Slovenia, Turkey.

Nomenclature

 *  balcanica. Stenamma (Aphaenogaster) testaceopilosa var. balcanica Emery, 1898c: 136 (w.) GREECE. Menozzi, 1936d: 271 (q.m.l.). Combination in Aphaenogaster: Forel, 1911d: 346. Subspecies of simonellii: Santschi, 1933c: 390. Raised to species: Agosti & Collingwood, 1987a: 53. Senior synonym of ionia: Boer, 2013: 65.
 * ionia. Aphaenogaster semipolita var. ionia Santschi, 1933c: 390 (w.) ITALY. [First available use of Aphaenogaster testaceopilosa subsp. semipolita var. ionia Emery, 1915a: 257; unavailable name.] Raised to species: Schembri & Collingwood, 1981: 423. Senior synonym of melitensis, ionia Baroni Urbani: Bolton, 1995b: 70. Junior synonym of balcanica: Boer, 2013: 65.

Description
Boer (2013):

Worker
Lateral sides of mesosoma with (not always distinct) longitudinal rugulae. Dorsal side of pronotum more or less scabriculous. Propodeum with or without transverse rugulae. Head in full-face view with distinct longitudinal rugulae with cross-connections. Dorsal side of postpetiole with longitudinal costulae which are continuing in microstriae on dorsal part of gastral base. Head in full-face view, mesosoma, lateral sides of petioles and dorsal side of petiolar node punctate. Terminal side of propodeum, beneath the propodeal spines weakly punctate to smooth. Dorsal side of postpetiole more or less weakly punctate. Head in full-face view and mesosoma matt with some shine from the punctation. Terminal side of the propodeum, lateral sides of gaster, legs and petioles glossy. Dorsal side of postpetiole and gaster satiny to glossy. Antennal club 4-segmented. Petiole equal in height to postpetiole or somewhat higher. Lateral shape of petiole variable, in general anterior side steeper than posterior side.

Measurements (n = 67). CI 72–80 (75); CL 1.14–1.57 (1.43) mm; CW 0.84–1.25 (1.09) mm; PHI 29–35 (31); PI 67–88 (78); PPPI 43–58, 64 (52); PSI 100–200 (156); PSLWI 83–145 (115); PWI 19–27 (22); RPH 117–161 (138); RPSI 18–67 (42); SI 133–161 (149); SI/CI 163–227 (197); SL 1.27–1.77 (1.60) mm; SPD 1–3 (1.4); 1–5.5 (3.3).

Queen
Longitudinal rugulae on: clypeus, head anterior to the occiput, mesoscutum and posterior side of postpetiole. Occiput indistinctly scabriculous. Transverse rugulae on pronotum and propodeum. Scutellum with oblique and transverse rugulae. Head, mesosoma and petioles punctate. Less than ten transverse microstriae present near base of first gastral tergite. Anterior side of the petiole smooth. Head, mesosoma and petioles shiny, dorsum gaster shiny satin. Terminal side of propodeum, beneath the propodeal spines mainly smooth and shiny. Antennal club 4-segmented. Scutellum rises less above mesoscutum and does not bend over metanotum.

Measurements (n = 1). CI 86; CL 1.50 mm; CW 1.30 mm; OCI 32; PHI 42; PI 70; PPPI 63; PSI 209; PSLWI: 110; PWI 28; RPH 150; RPSI 57; SI 119; SI/CI: 138; SL 1.38 mm; SPD 1; SPL 4.

Male
Weakly rugulate on mesosoma, not on mesopleura. Metanotum indistinctly striate. Punctation on head, mesosoma and dorsal sides of petioles. Lateral sides of petioles and gaster smooth. Dorsal side of gaster microreticulated, without or with very short microstriae on dorsal side of base of first gastral tergite. Head, pronotum, mesoscutum and scutellum matt, rest of body, especially some of the lateral parts of the mesosoma and the petioles glossy. Pubescence on scape and hind tibia subdecumbent to suberect, shorter than diameter of scape/tibia. Mandibles with one apical tooth, tooth 2 and or 3 smaller, 4–5 denticles. A transverse groove in middle of propodeal dorsum, so the terminal part of the propodeum is raised. Propodeum with two terminal knobs, triangular projections, slightly dentate or with short spines. Between these a weak longitudinal groove. Antennal club 5-segmented. Head without clear frontal midline. Scutellum slightly erect above mesoscutum, in whole or in part bent over metanotum.

Measurements (n = 10). CI 86–92 (90); CL 0.84–0.94 (0.89) mm; CW 0.75–0.87 (0.80) mm; EYI 38–44 (41); OCI 44–52 (48); SL/CL 42–49 (47); SL 0.37–0.46 (0.42) mm.