Temnothorax bimbache

Four nests were found under blackish, porous, volcanic, small stones. Nest situation showed a peculiar orientation: the stones were protected by vegetation and placed in the northern face. The ants occupied the first two cm of soil but also the holes and voids of the volcanic stone. Winged females eclosed at the laboratory in April and May 2004. (Espadaler 2007)

Identification
Espadaler (2007) - The closest relative of T. bimbache, which shows the same bicolored pattern, is Temnothorax risii, found in Tenerife and Gran Canaria. This last species is larger and has much shorter spines, a stouter petiole node and less shining head surface sculpture. Another related species is Temnothorax neminan, from the Anti-Atlas mountains in Morocco, that has similarly long spines but is smaller, and a dull surface sculpture and distinctly lower petiole node.

Distribution based on Regional Taxon Lists
Palaearctic Region: Canary Islands.

Nomenclature

 *  bimbache. Temnothorax bimbache Espadaler, 2007: 120, figs. 1  3 (w.q.) SPAIN (Canary Is).

Worker
Holotype: TL 3.7, HL 0.89, HW 0.73, CI 82, SL 0.78, SI 106, PW 0.52, ML 1.14.

Mandibles with fine longitudinal sculpture. Palp formula 5, 3. Clypeal margin convex and with a broad medial band smooth and shining. Median clypeal carina absent. Eyes large, maximum diameter 0.20-0.26, about 0.29-0.33 x HW, with 16-19 ommatidia in the longest row. Micropilosity present. Head in full-face view oval-shaped. Vertex margin slightly convex, with a slightly projecting rim visible in full-face view; posterolateral corners rounded. With mesosoma in profile the promesonotum evenly convex, the metanotal area with a shallowly impressed groove; propodeum with two long spines. Buschinger’s index 3.6. Femora strongly inflated. Petiole in profile with a slender neck and a broadly rounded and big node. An acute and long, directed anteriorly, subpetiolar process. Postpetiole in profile rounded and with a short posterior neck. In dorsal view the petiole node is oval-shaped, longer than wide. Postpetiole wider than long. Head sculpture: widely spaced longitudinal rugulae, with spaces smooth and shining or with vestiges of ground-sculpture. Rugulae reaching the vertex. Seven rugulae between frontal carinae. The area behind the eyes shows some irregular cross-meshes. Dorsum of promesonotum with a few longitudinal rugae, the space between them smooth and shining. Sides of mesosoma with irregular longitudinal rugae and a fine reticulum between them, but otherwise shining. Metanotal and propodeal dorsum without rugae, smooth and shining. Petiole with a pair of short rugae in the declivity to the neck and with a fine superficial shagreening, also present in the postpetiole. Gaster smooth and shining but for the hair pits. All dorsal surfaces of head and body with slightly curved or straight hairs wich are shorter on the head. Appendages without such long hairs. Longest pronotal hair 0.12. Bicolored, with the head and gaster deep brown. Legs brownish, contrasting with the orange-reddish mesosoma. The mesopleurae vary from pure red to brownish. Mandibles, antennae, orange. Petiole orange to brownish. Pospetiole brownish.

Queen
Follow the usual differences from workers. A main variation is the petiole shape, rather triangular in profile. The anterior medial zone of the scutum is infuscated, as are the two zones proximal to the tegulae.

Additional paratype measurements. Workers: TL 3.4-4.1, HL 0.88-0.96, HW 0.70-0.80, CI 78-85, SL 0.70-0.76 , SI 94-103, PW 0.50-0.56, ML 1.09-11.19. Queens: TL 4.9-5.5, HL 0.96-1.02, HW 0.84-0.92, CI 87-90, SL 0.76-0.80, SI 85-90, scutum width 0.92-1.02, ML 1.53-1.69.

Type Material
Holotype: Spain, Canary Islands, El Hierro, Punta de la Dehesa, 50m, N27º46.150’ W 18º7.621’, 17 December 2003, under small volcanic stone (X. Espadaler), presently deposited in my personal collection. Paratypes. 32 workers, 16 queens, all same data as holotype. On sixteen pins, each pin with 2 workers, one female (queens), deposited in, MCNC, , XEPC.

Etymology
The species is named after the “bimbaches”, as were named the former aboriginal people, cave-inhabitants of El Hierro.