Murmidius stoicus Hinton

Jałoszyński, Paweł & Ślipiński, Adam, 2022, Revision of the family Murmidiidae (Coleoptera: Coccinelloidea), Zootaxa 5109 (1), pp. 1-102 : 62-64

Murmidius stoicus Hinton

( Figs 183–190 )

Murmidius stoicus Hinton, 1942: 41 .

Type material examined. Holotype ( Singapore): ♂, “Singapore / J.C. Saunders / 17.iii.23”, “ BM1929-369 ”, “ Murmidius stoicus / Hinton / Type” ( BMNH).

Additional material studied. Myanmar: 1 ex., SE Myanmar, Dawna , 1- 20.01.1991 ( RSH) ; India: 1 ex., Tamil Nadu, Nilgiri Hills, 15 km SE Kotagiri, Kunchapannai , 900 m, 17- 28.11.1993, leg. Boukal & Kejval ( NHMB) ; Thailand: 1 ex., Mae Hong Son, Tom Lok , 8 km N. Mae Lang, 700 m, 11- 13.11.1985, Burckhardt & Löbl ( MHNG) ; China: 2 exx “in cane goods ex China intercepted Hobart, Tasmania , 30 - XI - 1979 ” ( ANIC) .

Emended diagnosis. Body short to moderately elongate oval and weakly convex, variously dark brown; antennal club only slightly elongate; anterior clypeal margin smooth; pronotum lacking lateral and sublateral longitudinal impressions; clypeus with distinct but only semi-matt microreticulation, reticulation on frons and vertex superficial and indistinct, remaining body parts glossy and smooth; elytra with fine but distinct and very dense punctures not arranged in rows; prosternal carinae slightly longer than 3/4 of prosternum; mesoventral plate with evenly rounded anterior margin, lacking anterior submarginal carina but with distinct lateral carinae curving anteromesad and nearly reaching anterior mesoventral margin; elytral epipleura not strongly narrowed at the level of metaventrite where they are nearly as wide as width of mesofemur; metaventrite with large, circular, unevenly distributed punctures on sides; penis conspicuously stout, in lateral view strongly curved with the very apex additionally strongly curved, hook-like; in ventral view penis strongly narrowing in distal half toward subtriangular and additionally weakly notched apex; tegmen conspicuously broad and stout, with distinct subtriangular apical notch, apex bearing 6–7 pairs of very long setae.

Redescription. BL 1.15–1.43 mm; BL/EW 1.49–1.68. Body short or weakly elongate oval ( Figs 183–185 ) and in lateral view weakly convex ( Fig. 186 ); pigmentation variously dark; dorsum covered with short whitish setae (discernible under magnification 40 ×); cuticle glossy, on clypeus weakly microreticulate and semi-matt, reticulation on frons and vertex weaker, indistinct, on pronotum and elytra indiscernible.

Head 0.28–0.38 mm wide; frons and vertex weakly convex, with fine, inconspicuous punctures; clypeus semimatt; eyes large, strongly convex, coarsely faceted. Antennal club ( Fig. 184 ) only slightly elongate.

Pronotum ( Figs 183–184 ) strongly transverse, widest at base; PL 0.25–0.28 mm, PW 0.53–0.70 mm, PL/PW 0.39–0.48; lateral margins weakly rounded and moderately strongly convergent anterad, with narrow but distinct lateral carinae; mesal corners of antennal cavities weakly projecting anterad; lateral and sublateral longitudinal impressions lacking; anterior pronotal margin lacking marginal line. Punctures on disc fine and barely discernible, except for anterolateral groups of large but shallow punctures that extend mesad along anterior pronotal margin, but this irregular transverse anterior row is composed of diffuse and shallow punctures and in some specimens incomplete, interrupted at middle.

Prosternum ( Fig. 185 ) with barely discernible transverse microreticulation and with fine, inconspicuous setiferous punctures; prosternal carinae slightly longer than 3/4 of prosternum and their anterior portions abruptly bent laterad; notosternal carinae nearly straight and not reaching anterior prosternal margin, the latter with distinct narrow marginal carina.

Elytra ( Figs 183–184 ) together oval, with strongly rounded sides, broadest distinctly in front of middle, EL 0.78–0.98 mm, EW 0.70–0.93 mm, EL/EW 1.03–1.15. Humerus with distinct callus; elytra very densely punctate, punctures small but distinct, not arranged in rows, those on anteromedian region of each elytron separated by spaces subequal to their diameters, punctures slightly reducing in depth toward sides and apices. Epipleura not narrowed near middle, with convex margins.

Hind wings fully developed.

Mesoventral plate ( Fig. 187 ) with fine lateral longitudinal carinae curved anteromesad and not connected into anterior submarginal carina; anterior margin evenly, broadly rounded.

Metaventrite ( Fig. 187 ) with large, circular and distinct punctures unevenly distributed on sides; median region with fine, inconspicuous setiferous punctures. Discrimen externally poorly marked or indiscernible.

Tarsi with short, inconspicuous setae on tarsomeres 1–3.

Aedeagus ( Figs 188–190 ) 0.35 mm long, conspicuously stout; penis in ventral view parallel-sided in proximal half and strongly narrowing in distal half toward subtriangular and distinctly notched apex, in lateral view strongly curved, with hook-like apical portion; tegmen stout, much longer than half-length of penis, with triangular apex bearing deep median notch and 6–7 pairs of very long setae.

Distribution. Presumably Oriental ( Singapore, Thailand, India, Myanmar, presumably tropical China).

Remarks. The status of this species is somewhat problematic and larger material is necessary to clarify whether it is one variable taxon or a complex of several species. The studied specimens show a remarkable variability in the body shape and length, and the number of well-preserved males is not sufficient to assess the possible variability of genital structures. The illustrated aedeagus is that of a male from Myanmar. Presumably adventive specimens of Murmidius collected in the Great Britain, preserved at BMNH and identified as M. segregatus (labels by Hinton and Booth) may in fact belong to M. stoicus , or to a yet undescribed, closely related species.

Figures

FIGURES 183–190. Morphological structures of Murmidius stoicus Hinton. Body in dorsal (183–184), ventral (185) and lat- eral (186) views; pterothorax in ventral view (187); aedeagus (188), isolated tegmen (189), and aedeagus (190).