Murmidius lankanus, Jałoszyński & Ślipiński, 2022

Jałoszyński, Paweł & Ślipiński, Adam, 2022, Revision of the family Murmidiidae (Coleoptera: Coccinelloidea), Zootaxa 5109 (1), pp. 1-102 : 66-68

Murmidius lankanus sp. n.

( Figs 198–205 )

Type material examined. Holotype ( Sri Lanka): ♂, “Sri Lanka: Centr. Prov. / Matale District / 5 km S Dambulla, leg. Schuh 26.12.2000 ” ( NHMW) . Paratypes: 2 exx, same data as for holotype ( RSH) .

Diagnosis. Body moderately elongate oval and weakly convex, moderately light brown to dark brown; antennal club only slightly elongate; anterior clypeal margin smooth; pronotum lacking lateral and sublateral longitudinal impressions; clypeus with distinct semi-matt to matt microreticulation, reticulation on frons, vertex and pronotum superficial and fine but distinct, elytra glossy and smooth; elytra with fine but distinct and very dense punctures not arranged in rows; prosternal carinae not exceeding 1/3 of prosternum; mesoventral plate with evenly rounded anterior margin, with distinct anterior submarginal carina but lacking lateral carinae; elytral epipleura not strongly narrowed at the level of metaventrite where they are nearly as wide as width of mesofemur; metaventrite with large but shallow, circular, unevenly distributed punctures on sides; penis stout, in lateral view bent in sub-basal and subapical regions; in ventral view gradually narrowing in distal half toward truncate apex; tegmen stout, with deep median apical notch, apical region bearing 5–6 pairs of long setae distributed apically and subapically, and several minute marginal subapical setae.

Description. BL 1.23–1.30 mm; BL/EW 1.47–1.63. Body elongate oval ( Figs 198–200 ) and in lateral view weakly convex ( Fig. 201 ); pigmentation moderately light to dark brown; dorsum covered with short whitish setae (discernible under magnification 80 ×); cuticle glossy, only clypeus matt or semi-matt, microreticulation on frons, vertex and pronotum weaker and superficial, surface glossy, elytra smooth and glossy.

Head 0.33 mm wide; frons and vertex weakly convex, with fine, inconspicuous punctures; clypeus semi-matt or matt; eyes large, strongly convex, coarsely faceted. Antennal club ( Fig. 200 ) only slightly elongate.

Pronotum ( Figs 198–199 ) strongly transverse, widest at base; PL 0.25–0.28 mm, PW 0.63–0.65 mm, PL/PW 0.40–0.44; 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 uniform and fine, inconspicuous.

Prosternum ( Fig. 200 ) with barely discernible transverse microreticulation and with fine, inconspicuous setiferous punctures; prosternal carinae conspicuously short, about as long as 1/3 of prosternum and nearly straight; notosternal carinae nearly straight and not reaching anterior prosternal margin, the latter lacking marginal carina.

Elytra ( Figs 198–199 ) together oval, with strongly rounded sides, broadest distinctly in front of middle, EL 0.88–0.93 mm, EW 0.80–0.85 mm, EL/EW 1.03–1.16. 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. 202 ) lacking lateral longitudinal carinae, with distinct and complete anterior submarginal carina; anterior margin evenly, broadly rounded.

Metaventrite ( Fig. 202 ) with large, circular and shallow but 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 203–205 ) 0.35 mm long, stout; penis in ventral view broadest slightly before middle and gradually narrowing in distal half toward truncate apex ( Fig. 205 ), in lateral view bent in sub-basal and subapical regions; tegmen stout, nearly as long as penis, with subtriangular apex bearing deep median notch; apical region bearing 5–6 pairs of long setae distributed apically and subapically, and several minute marginal subapical setae.

Distribution. Sri Lanka.

Etymology. Topotypical, after the island of Sri Lanka.

Remarks. Externally, M. lankanus closely resembles M. hebrus and M. merkli . It clearly differs from the latter in extremely short prosternal carinae, a feature shared with M. hebrus . The most reliable characters to distinguish M. lankanus from M. hebrus are those associated with the aedeagus: the shape of penis in lateral view, the apical region of penis in ventral or dorsal view, and the setal pattern on the tegmen clearly differ. In addition, a character that seems to constantly differ is the shape of the metaventral femoral line: evenly rounded in M. lankanus , and shallowly sinuate in M. hebrus . However, more specimens are necessary to assess value of this feature.

Figures

FIGURES 198–205. Morphological structures of Murmidius lankanus sp. n. Body in dorsal (198–199), ventral (200) and lateral (201) views; pterothorax in ventral view (202); aedeagus (203–204), and apical portion of penis (205).