Nossidium schuelkei sp. n. (Figs. 4 A –F, 5 A–E) Length 0.84 mm. Body dark brown covered with grey/yellow overlapping pubescence, legs and antennae dusky yellow, lateral and posterior borders with a sharply defined yellow margin in transmitted light. Antennomeres 3–8 length 0.33 mm, 4–8 elongate, 10,11 globular, Fig. 4D. Width across eyes 0.31 mm. Mentum broadest at anterior margin tapering towards base, two longest setae situated medially on lateral margins, Fig. 5C. Pronotum length 0.24 mm, width 0.50 mm, posterior margin sinuate before the angles. Elytra length 0.56 mm, width 0.53 mm, widest just behind humeri, wings of usual Nossidium type, Fig. 4E. Mesoventral collar reaching onto the humeri with a raised anterior border and a vertically oriented medial ridge, Fig. 5B; mesoventral keel wide, reaching below the mesocoxae in dorsal view and with a flattened cap rounded anteriorly and with a raised border, closely fitting posteriorly with the metaventrum so as to appear an anterior metaventral process, Fig. 5A. Metaventrum with line of metepisternal suture reaching mesocoxae but not directed posteriad at lateral margins; lateral points on the posterior intercoxal process broadened and flattened towards the base with convex lateral margins, Fig. 5 F. Pygidium with +/– 15 teeth Fig. 5 G. Male: not known. Female: spermatheca Fig. 4 F. Etymology. Named after the collector Michael Schülke of the Museum für Naturkunde, Berlin. Diagnosis. The new species is similar to N. katyae but may be distinguished by its less shining, broader and more rounded form with less posteriorly tapering elytra; by the form of the mesoventral keel which is more rounded anteriorly and with a raised border (Figs. 5A /B, katyae Fig. 5 F) and by the form of the lateral points on the posterior intercoxal process of the metaventrum which are broader basally and much less sharply pointed (Fig. 5D, katyae Fig. 5 G) For differences of N. schuelkei and N. katyae with N. pilosellum, see Darby (2015). Type data. Holotype: ♀, Costa Rica, Osa Peninsula, Road, Bahia Drake to Rincon de Osa, forest and plantations, car net devart, 8.41–42 N 83.29 –40W, 0–400m, 9.x.2012, 1500–1700 hrs, Schülke & Grünberg (INBio). Paratype: ♀, same data as holotype (INBio).

Published as part of Darby, Michael, 2016, New Species and Records of Costa Rican Featherwing Beetles (Coleoptera: Ptiliidae), pp. 41-51 in Zootaxa 4184 (1) on pages 44-45, DOI: 10.11646/zootaxa.4184.1.2, http://zenodo.org/record/164467