Pselaphopluteum, Owens & Leschen & Carlton, 2019

Owens, Brittany E., Leschen, Richard A. B. & Carlton, Christopher, 2019, The Pselaphini (Coleoptera: Staphylinidae: Pselaphinae) of the Subantarctic and Chatham Islands of New Zealand; Description of Five Species and One Genus, Insect Systematics and Diversity 3 (2019), No. 2, pp. 1-14 : 8-9

Pselaphopluteum , gen. nov.

(u r n:l s i d:z o o b a n k.o r g:a c t: A A F2 3 8 3 7- 7 4B C - 4 3A0-8 7 7F - 6FB747C74C87)

Type species

Pselaphopluteum motumaha , sp. nov.

Etymology

The genus name is a combination of the prefix ‘pselaph-’ which is common among other genera in the tribe Pselaphini and ‘pluteum’, the Latin word for ‘shelf’, which refers to the shelf-like form of the gular modifications in members of the genus. Gender neutral.

Diagnosis

Head with large vertexal depression between eyes; frontal margin of rostrum rounded; gular mound greatly expanded and shelf-like; maxillary palpomeres short, maxillary palpomere 4 weakly pedunculate, apical sensory patch absent. Pronotum with antebasal sulcus, lateral antebasal fovea, median basal fovea, and inner basolateral fovea present. The form of the shelf-like gular mound in combination with the shortened, pedunculate maxillary palpomere 4 easily distinguish Pselaphoplutuem from all other genera of Pselaphini in New Zealand.

Description. Male

Based on male holotype and male specimens of the paratype series of Pselaphopluteum motumaha . Body length: 2.5–2.7 mm. Integument: Body and appendages light brown, shining. Head: Occiput with median sulcus beginning at base and extending anteriorly, confluent with vertexal depression. Vertexal foveae large, setose, set obliquely into margins of broad vertexal depression parallel to middle of eyes. Vertexal depression occupying expanse of vertex between eyes, confluent with narrower sulcus extending to apex of rostrum. Rostral sulcus bounded by carinate lateral ridges extending to anterior margin of rostrum. Frontal margin of rostrum slightly rounded, with small median notch and patch of erect setae in dorsal view. When viewed laterally, gular mound greatly expanded, flattened and shelf-like. Area of head posterior to gular mound smooth, shining, gular foveae present, paired. Labrum narrowed basally and widened at apex. Mandible slightly falcate. Maxillary palpomere 1 narrow, elongate; palpomere 2 narrow, widened distally; maxillary palpomere 3 short, triangular-rounded; maxillary palpomere 4 shorter than length of head, weakly pedunculate, visible sensory patches absent. Thorax: Pronotum widest at anterior 1/3, narrowed anteriorly and posteriorly. Lateral basal sulcus present, delimited by lateral antebasal foveae, single median antebasal fovea present, inner basolateral fovea present. Prosternum in front of coxae flattened, nude, lateral procoxal foveae present. Profemur modified, flattened ventrally; protibia narrow and curved along length. Mesoventrite with median shield, lateral mesoventral foveae present in large lateral pits filled with dense spongeose setae, lateral mesocoxal foveae absent, median mesoventral foveae present, paired. Mesocoxae approximate, not separated by extension of meso- or metaventrite; mesofemur modified, flattened ventrally; mesotibia narrow and curved along length. Metaventrite afoveate. Metacoxae separated by extension of first ventrite. Elytron with three basal foveae present, discal striae absent, sutural striae present. Abdomen: Tergites of usual form for tribe, otherwise unmodified. First ventrite covered in dense, shining setae. Second ventrite with basal band of shining modified setae, narrow median depression extending from base to apex of ventrite, depression bounded laterally by short setae from 1/2 length of ventrite to apex. Genitalia: Asymmetrical. Basal bulb distinct, dorsal diaphragm present. Parameres paired, lateral. Median lobe expanded and complex distally. Ventral and accessory processes present.

Distribution

This genus is known only from specimens collected from Adams Island, Auckland Island, and nearby Enderby Island.