Syrraphesina agostii Yin & Hlaváč, 2020

Yin, Zi-Wei & Hlaváč, Peter, 2020, A second species of Syrraphesina Raffray found adjacent to Wallace's Line (Coleoptera, Staphylinidae, Pselaphinae), Zootaxa 4852 (2), pp. 203-210 : 204-207

Syrraphesina agostii Yin & Hlaváč , sp. nov.

( Figs 1–4 )

Type material. HOLOTYPE: INDONESIA: ♂, ‘ INDONESIA: Lombok , Pusuk , 15 km N Ampenan, pass Ampenan/ Pemnenang, 550 m, 11.iii.1991, leg. D. Agosti #4 / locality known as Monkey forest, second forest on ridge, sample on top of the ridge #4’ ( MHNG) . PARATYPES: INDONESIA: 1 ♀, same collection data as holotype ( MHNG) ; 1 ♂, 2 ♀♀, ‘INDON: Lombok, Batu Koq (N of G. Rinjani), 500 m, 12.iii.1991, Sec. forest in gorge, along river, leg. D. Agosti F91527 -531 #5’ ( MHNG, PCPH) .

Description. Male ( Fig. 1A ). Body length (combined length of head, pronotum, elytra and abdomen) 1.62–1.81 mm; reddish-brown. Head ( Fig. 2 B–D) much longer than wide, length from anterior margin of clypeus to head base (excluding neck region) 0.43–0.48 mm, width across eyes 0.21–0.25 mm; anterior margin of clypeus broadly arcuate, with two protuberances each bearing tuft of setae; each eye composed of approximately 25 facets. Antennae ( Fig. 2A ) strongly clubbed, length of exposed parts 0.37–0.44 mm; scapes and pedicels short, antennomere 3 much narrower at base than pedicel at apex, basally pedunculate and widening apically, antennomere 4 short, strongly transverse, antennomere 5 barrel-shaped, truncate at apex, which is covered with long, dense setae. Pronotum ( Fig. 2E ) pentagonal, slightly wider than long, length along midline 0.28–0.32 mm, maximum width 0.32–0.36 mm. Prosternum ( Fig. 2F ) with large, suboval setose area at middle, anterior margin of procoxal cavities distinctly carinate. Elytra ( Figs 1A, B ; 3A ) subtriangular, much wider than long, length along suture 0.40–0.46 mm, maximum width 0.72–0.80 mm; lacking tufts of setae at posterolateral margins. Mesoventrite ( Fig. 3B ) with specialized secretory bands along midline and anterior margin; metaventrite ( Fig. 3B ) medially strongly convex, lacking microsculpture. Legs simple, lacking spines or protuberances. Abdomen robust, much wider than long, and slightly wider than elytra, length along midline 0.51–0.55 mm, maximum width 0.73–0.82 mm; composite tergite ( Fig. 3C ) medially broadly and deeply concave, with tufts of trichomes at basolateral regions, with large and deep cavities lateral to trichomes; first pair of paratergites with two groups of linear and triangular trichomes, largely covering trichomes on tergite below. Sternites 1 (III) and mediobasal margin of sternite 2 (IV) (Fig, 3D) with rhombic microsculpture, sternite 6 (VIII) ( Fig. 4A ) transverse, with two pairs of membranous processes on anterior margin. Aedeagus ( Fig. 4 B–D) strongly sclerotized, symmetrical, length 0.35 mm (only that of paratype male is measured); median lobe divided into apical and basal parts, apical part narrowing apically, apex roundly truncate, with two curved preapical setae.

Female ( Fig. 1B, C ). Similar to male in external morphology; body size much larger; tergites 4–5 (VII–VIII) less vertical than male in dorsal view; each eye composed of approximately 22 facets. Measurements (as for male): Body length 1.97–1.99 mm, length/width of head 0.46–0.51/ 0.24–0.25 mm, pronotum 0.32–0.34/ 0.34–0.36 mm, elytra 0.40–0.43/ 0.77–0.83 mm, abdomen 0.54–0.64/ 0.78–0.85 mm, length of antenna 0.36–0.42 mm.

Comparative notes. Syrraphesina agostii can be readily separated from the only congener, S. pliciventris , by the larger body size (1.62–1.99 vs 1.4 mm), and the relatively much shorter head and antennae.

Host ant. Unknown.

Distribution. Indonesia: West Nusa Tenggara (Lombok Island) ( Fig. 4E ).

Etymology. The new species is named after Donat Agosti, a well-known myrmecologist and collector of the type series.

Figures

FIGURE 1. Dorsal (A, B) and lateral (C) habitus of Syrraphesina agostii. A. Male. B, C. Female. Scale bars: 0.5 mm.

FIGURE 2. Morphology of Syrraphesina agostii. A. Right antenna. B–D. Head, in dorsal (B), lateral (C), and ventral (D) view. E. Pronotum. F. Prosternum. Scale bars: 0.2 mm in A, E, F; 0.1 mm in B–D.

FIGURE 3. Morphology of Syrraphesina agostii. A. Right elytron. B. Meso- and metaventrite. C, D. Abdomen, dorsal (C), and ventral (D). Scale bars: 0.2 mm.

FIGURE 4. Morphology of Syrraphesina agostii, and distribution of Syrraphesina. A. Male sternite 6 (VIII). B–D. Aedeagus, dorsal (B), lateral (C), and ventral (D). E. Distribution of Syrraphesina in the Oriental and Australasian regions. Scale bars: 0.1 mm.