Solenopsis bucki

Solenopsis bucki was collected in leaf litter.

Identification
A New World thief ant that is a member of the globularia species complex

Pacheco and Mackay (2013) – Worker - The worker is easily recognized by its greatly dilated postpetiole, which is 0.220 mm in length, 0.220 mm in height and 0.300 mm in width. The eye is moderately large with 20 ommatidia. The mandible has two teeth and unique to this species within the members of the globularia species complex and within the New World Solenopsis.

The greatly dilated postpetiole places S. bucki into the globularia species complex. Solenopsis bucki can be separated from Solenopsis globularia by the narrow, straight mandibles that only have two teeth on the masticatory margin. Solenopsis bucki does not have a medial tooth on the clypeal margin, a feature found in other species of the globularia species complex. Moreover, S. bucki is missing horizontal striae on the mesopleuron, a trait found in S. globularia. Solenopsis bucki is similar to Solenopsis loretana as well and occurs in the same general area, but can be separated as S. bucki has an eye of 20 ommatidia and S. loretana has at the most five ommatidia.

Keys

 * Key to New World Solenopsis Species Complexes
 * Key to workers of the globularia species complex / Clave para las obreras del complejo globularia

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Castes
Known only from the worker caste.

Nomenclature

 *  bucki. Solenopsis bucki Kempf, 1973a: 30, figs. 1-3 (w.) BRAZIL.

Worker
Pacheco and Mackay (2013) - Measurements (n=1) [may not correspond to our definitions]. TL 2.60; HL 0.580; HW 0.460; SL 0.380; CI 80.0; SI 65.0; PL 0.200; PW 0.170; PPL 0.220; PPW 0.300.

Moderately large; chestnut red head, postpetiole and first gastral tergum, with lighter appendages; head quadrate, longer than wide; mandible straight, oblique, masticatory margin bidentate; lateral clypeal teeth well developed, extralateral teeth reduced, angulate, medial tooth absent; clypeal carinae well defined; scape long, does not reach posterior border of head; minor funicular segments moderately long; eyes large, 20 ommatidia; pronotum and mesopleuron smooth and shiny, lacking sculpturing; notopropodeal suture well depressed, notch-like, groove breaks sculpture of mesosoma; metapleuron horizontally striated; thorax 0.650 mm in length, 0.320 mm in width; length of posterior femur 0.320 mm; petiolar node much smaller than postpetiole viewed laterally and dorsally; petiole height, 0.250 mm, lacking tooth or flange ventrally; postpetiolar node globose, dilated, postpetiolar height 0.220 mm, lacking tooth or flange ventrally; gaster length, 0.790 mm, width 0.500 mm.

Moderately pilose; erect hairs of nearly equal length on most body surfaces; short dense hairs on mandibles and antennae, not thicker than maximum diameter of scape.

Type Material
Single holotype worker sifted from leaf litter, Brazil, Erechim, Rio Grande do Sul, vii-1960, F. Plaumann col. (holotype WWK no, 8098, not available).