Royidris etiolata

R. etiolata nests under stones in spiny forest.

Identification
A member of the notorthotenes species group. Bolton and Fisher (2014) - Workers of etiolata mostly conform to the description of Royidris notorthotenes. The two are closely related but separated by the comparative dimensions noted below, most striking of which is the extremely elongate scape. In addition, etiolata is a more gracile species. Its head in full-face view has the sides behind the eyes strongly convergent posteriorly, so that the transverse portion of the posterior margin always appears shorter and narrower than in notorthotenes. For comparison of measurements see Table 3, Bolton and Fisher 2014.

Distribution
Endemic to Madagascar.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Castes
Known only from the worker caste.

Nomenclature

 *  etiolata. Royidris etiolata Bolton & Fisher, 2014: 52, figs. 51-53, Map 139 (w.) MADAGASCAR.

Worker
(holotype in parentheses). TL 3.5–4.2 (3.9), HL 0.88–1.00 (0.98), HW 0.66–0.77 (0.75), CI 75–78 (77), SL 1.04–1.20 (1.14), SI 148–158 (152), PW 0.42–0.50 (0.48), WL 1.14–1.36 (1.30) (11 measured). EL 0.21–0.24 (EL/HW 0.31–0.32). MfL 0.98–1.14 (MfL/HW 1.46–1.50, MfL/MfH 4.00–4.38).

Workers of etiolata mostly conform to the description of Royidris notorthotenes. The two are closely related but separated by the comparative dimensions noted below, most striking of which is the extremely elongate scape. In addition, etiolata is a more gracile species. Its head in full-face view has the sides behind the eyes strongly convergent posteriorly, so that the transverse portion of the posterior margin always appears shorter and narrower than in notorthotenes. For comparison of measurements see Table 3, Bolton and Fisher 2014.

Type Material
Holotype worker, Madagascar: Prov. Toliara, Mahafaly Plateau, 6.2 km. 74° ENE Itampolo, 24°39.2’S, 43°59.8’E, 80 m., 21–25.ii.2002, BLF 5796, CASENT0002370, under stone, spiny forest/thicket (Fisher et al.). Paratypes. 9 workers with same data as holotype but 3 workers CASENT0002371, 1 worker CASENT0002372, 1 worker CASENT0002437, 3 workers CASENT0002438, 1 worker CASENT0009799 (CASC, ).

References based on Global Ant Biodiversity Informatics

 * Bolton B., and B. L. Fisher. 2014. The Madagascan endemic myrmicine ants related to Eutetramorium (Hymenoptera: Formicidae): taxonomy of the genera Eutetramorium Emery, Malagidris nom. n., Myrmisaraka gen. n., Royidris gen. n., and Vitsika gen. n. Zootaxa 3791(1): 1-99.