Americoptilium nigrescens, Darby, 2020

Darby, Michael, 2020, Eight new species of Ptenidiini and Discheramocephalini (Coleoptera: Ptiliidae) from Ecuador, European Journal of Taxonomy 599, pp. 1-19 : 12-13

Americoptilium nigrescens sp. nov.

urn:lsid:zoobank.org:act:447F0DE6-7AF8-4197-ABE2-00CCCF5EC8DE

Fig. 6 A–D

Etymology

Named after the dark colour of the species.

Material examined

Holotype

ECUADOR • ♂; Napo, Cosanga, Camp ; 2100 a.s.l.; 30 May 2018; tray; J. McClarin leg.; QCAZM.

Description

SIZE. Habitus length 0.65 mm ( Fig. 6A ).

COLOUR. Dark brown/black, shining, appearing polished, very finely and sparsely punctured with very short pubescence, legs and antennae yellow/brown, antennal club darker.

HEAD. Partially concealed by pronotum in dorsal view. Pubescence on anterior part of disc longer than on pronotum and elytra; width across eyes 0.19 mm; antennomeres III–XI length 0.24 mm; mentum and prementum chaetotaxy difficult to make out, sides strongly rounded to anterior margin.

PRONOTUM. Length 0.21 mm, width 0.20 mm, globular, tapering strongly to narrow waist before elytra, lateral margins finely bordered.

ELYTRA. Length 0.43 mm, width 0.28 mm, strongly rounded to narrow waist, widest medially, then straightening and tapering posteriorly.

SCUTELLUM. Narrow, elongate.

PROSTERNUM. Wide in front of the adjacent procoxae.

MESOVENTRITE. Glabrous and without reticulation, form of collar unclear, without humeri; mid-keel and keel fused, widest anteriorly and tapering to point between the procoxae; procoxal anterior border wide and right angled; mesocoxae narrowly separated; meso/metaventrite suture obscured.

METAVENTRITE. Length 0.17 mm, width 0.25 mm, sparsely pubescent, distance between metacoxae 0.03 mm, metepisternal sutures not visible.

MALE GENITALIA. Aedeagus ( Figs 5 Ba–Bb).

FEMALE GENITALIA. Not known.

Remarks

Description of this species on the basis of a single specimen is considered to be justified by the rarity of this genus, only one other specimen of which, the holotype of A. convexum Darby, 2018 , a female, also from Ecuador, is known. Americoptilium nigrescens sp. nov. is distinguished from that species by the less rounded and narrower body form, and the darker colour. It is possible, should the species be shown in the future to exhibit sexual dimorphism, that A. nigrescens sp. nov. might be confirmed as a male A. convexum , though it should be noted that in describing the three species of the closely related African genus Africoptilium, Johnson (1967) did not mention sexual dimorphism as being present, and neither did Grebennikov (2009) in his later redescription of that genus.

Figures

Fig. 6. Americoptilium nigrescens sp. nov. A. Habitus. B. Dorsal (Ba) and lateral (Bb) views of the aedeagus. C. Mesoventrite ×675. D. Venter ×240.

Fig. 5. Notoptenidium brunneum sp. nov. A. Habitus. B. Venter ×298. C. Spermatheca. D. Mentum and prementum ×1460. E. Mesoventrite ×595. F. Posterior margin of the metaventrite between the metacoxae ×590. G. Prosternum ×595.