Murmidius hawaiianus, Jałoszyński & Ślipiński, 2022

Jałoszyński, Paweł & Ślipiński, Adam, 2022, Revision of the family Murmidiidae (Coleoptera: Coccinelloidea), Zootaxa 5109 (1), pp. 1-102 : 58-60

Murmidius hawaiianus sp. n.

( Figs 170–176 )

Type material examined. Holotype (Hawaii): ♂, “ Hawaii: Oahu / Diamond Head , / beach & s.slopes / 30 May 1991 / W. E. Steiner ”, “Under dry bark of / fire-killed / Prosopis pallida” ( USNM) . Paratypes (3 exx): 2 exx, same data as for holotype ; 1 ex., same data except for 9 June ( USNM) .

Diagnosis. Body elongate oval and weakly convex, umbra-brown; antennal club only slightly elongate; anterior clypeal margin smooth; pronotum lacking lateral and sublateral longitudinal impressions; clypeus with distinct matt microreticulation, frons and vertex with distinct, but more superficial and less matt microreticulation, pronotum with extremely fine and superficial but distinct microreticulation, elytra glossy; elytra with very fine but distinct and very dense punctures not arranged in rows; prosternal carinae as long as 2/3 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 stout, in lateral view distinctly but weakly curved; in ventral view largely subparallel with broadly rounded apex; tegmen much longer than half of penis, with triangular apex bearing one pair of long setae accompanied with several minute apical and subapical setae.

Description. BL 1.43–1.53 mm; BL/EW 1.58–1.71. Body elongate oval ( Figs 170–172 ) and in lateral view weakly convex ( Fig. 173 ); pigmentation umbra-brown; dorsum covered with short whitish setae (discernible under magnification 40 ×); cuticle feebly glossy, on clypeus distinctly microreticulate and matt, reticulation on frons and vertex, slightly weaker, on pronotum very fine and superficial, on elytra indiscernible.

Head 0.38–0.39 mm wide; frons and vertex weakly convex, with fine, inconspicuous punctures; clypeus matt; eyes large, strongly convex, coarsely faceted. Antennal club ( Figs 170–172 ) only slightly elongate.

Pronotum ( Figs 170–171 ) strongly transverse, widest at base; PL 0.30–0.33 mm, PW 0.65–0.70 mm, PL/PW 0.43–0.48; 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.

Prosternum ( Fig. 172 ) with barely discernible transverse microreticulation and with fine, inconspicuous setiferous punctures; prosternal carinae about as long as 2/3 of prosternum and their anterior portions slightly curved laterad; notosternal carinae nearly straight and not reaching anterior prosternal margin, the latter with distinct narrow marginal carina.

Elytra ( Figs 170–171 ) together oval, with strongly rounded sides, broadest distinctly in front of middle, EL 0.95–1.00 mm, EW 0.88–0.93 mm, EL/EW 1.06–1.14. 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. 174 ) with fine lateral longitudinal carinae curved anteromesad and not connected into anterior submarginal carina; anterior margin evenly, broadly rounded.

Metaventrite ( Fig. 174 ) with large, circular and distinct punctures unevenly distributed on sides; median region with fine, inconspicuous setiferous punctures. Discrimen externally poorly marked.

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

Aedeagus ( Figs 175–176 ) 0.45 mm long, relatively stout; penis in ventral view largely sub-parallel with broadly rounded apex, in lateral view distinctly but weakly curved; tegmen stout, much longer than half-length of penis, with triangular apex bearing one pair of long setae accompanied by several minute setae distributed along distal and lateral margins of triangular region.

Distribution. Hawaiian Islands (Oahu).

Etymology. Topotypical, after Hawaiian Islands.

Remarks. The four studied specimens, all collected on the same spot, show little variability and differ clearly from similar species ( M. irregularis , M. segregatus and M. stoicus ) in elongate body shape, matt or semi-matt microreticulation of the head and pronotum, and the aedeagus.

Figures

FIGURES 170–176. Morphological structures of Murmidius hawaiianus sp. n. Body in dorsal (170–171), ventral (172) and lateral (173) views; pterothorax in ventral view (174); and aedeagus (175–176).