Eurhopalothrix speciosa

Identification
Longino (2013): This species shares the elevated posterior mesonotal keel with Eurhopalothrix hunhau and Eurhopalothrix sepultura. Eurhopalothrix hunhau has a full complement of 18 specialized setae on the face; both E. sepultura and E. speciosa have a reduced number. The head shape of E. speciosa is very similar to E. sepultura. Eurhopalothrix speciosa has a distinctive arrangement of 6 specialized setae on the face: 4 in a tight square on the posteromedian vertex, and 2 on the posterolateral angles of the vertex margin. In contrast, Eurhopalothrix sepultura has the same medial square of 4 setae, but 4–6 additional setae are arranged anteriorly, between the medial square and the compound eyes, and there are no setae on the posterolateral angles of the vertex margin. Also, the compound eye of E. speciosa is relatively large, with 7–8 ommatidia across greatest diameter, versus 5 in E. sepultura.

Key to New World Eurhopalothrix

Distribution
Brazil (Santa Catarina, Sao Paulo)

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Nomenclature

 *  speciosa. Eurhopalothrix speciosa Brown & Kempf, 1960: 203, figs. 31-33 (w.) BRAZIL.

Worker
Holotype: TL 2.8, HL 0.76, H W 0.78 (CI 103), scape L 0.49, maximum diameter of compound eye 0.09, WL 0.72 mm. Form of head and body as shown in the figures.

This is a medium-sized member of the bolaui group notable for the reduction of its pilosity. The appressed and subappressed ground pilosity consists of small to minute, mostly simple hairs, rather dense on mandibles and clypeus, sparse on dorsum of nodes and gaster, and very sparse and inconspicuous on vertex, occiput and alitruncal dorsum. Simple appressed small hairs of the legs give way on the tibiae, especially the flexor surfaces, to appressed and decumbent spatulate hairs. Extensor apical point of each tibia with the short, thick clavate hair usual for the genus. The larger specialized hairs are thick-squamiform, reduced in number on the head, and are set in marginate foveae that tend to be more distinct than in related species. The close rectangular group on the median field of the occiput is especially characteristic. Humeral pair absent on holotype and both paratypes, indicating that they are probably truly lacking and not just rubbed off. The two pairs of mesonotal hairs are exceptionally large and thick, and the posterior pair is set in contiguous foveae separated by a short longitudinal carina. Other hairs of the large type arranged as usual in this group of species; median postpetiolar pair small. Promesonotal suture virtually obsolete; metanotal groove present but indistinct. Body densely punctulate-granulose, opaque; dorsum of head finely rugulose in addition. Clypeus and gaster finely and densely punctulate, subopaque (narrow interspaces mostly individually shining). Mandibles almost smooth, moderately shining, with about 8 or 9 teeth (not dissected). Color medium ferruginous; legs and pleura more yellowish.

The Plaumann collected paratype is larger than the holotype: TL 3.3, HL 0.87, HW 0.89 (CI 102), scape L 0.54, maximum diameter of eye 0.12, WL 0.85 mm. Front of head more irregularly rugulose, the sculpture less longitudinally oriented; dorsum of alitrunk more rugulose. Large hairs on occiput and mesonotum less strongly inflated. Otherwise similar to holotype.

Type Material
Longino (2013) - Holotype worker: Brazil, Santa Catarina: Nova Teutonia, May 1957, sifted from leaf mold (F. Plaumann), WWK No. 2648] (not examined). Paratype workers: same data as holotype ; Serra Geral, Dec 1958, sifted from leaf mold (F. Plaumann) MZSP, WWK No. 3004.