Murmidius segregatus Waterhouse

Jałoszyński, Paweł & Ślipiński, Adam, 2022, Revision of the family Murmidiidae (Coleoptera: Coccinelloidea), Zootaxa 5109 (1), pp. 1-102 : 60-62

Murmidius segregatus Waterhouse

( Figs 177–182 )

Murmidius segregatus Waterhouse, 1876: 114 .

Type material examined. Lectotype [here designated by P. Jałoszyński] (Mascarenes): ♂, “Rodriguez / G. Gulliv- er / 76-15”, “ Murmidius / segregatus / (Type) C.Waterh. ”, “Type / HT” ( BMNH).

Emended diagnosis. Body elongate oval and weakly convex, moderately light brown; antennal club only slightly elongate; anterior clypeal margin smooth; pronotum lacking lateral and sublateral longitudinal impressions; clypeus with indistinct and superficial microreticulation, moderately glossy, remaining body parts lacking distinct microreticulation, pronotum and elytra particularly glossy; elytra with very 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 slender, in lateral view weakly curved; in ventral view slightly narrowing up to distal 1/4 and again broadening toward broadly rounded apex; tegmen longer than half of penis, with slightly emarginate apex bearing one pair of long setae.

Redescription. BL 1.28 mm; BL/EW 1.59. Body elongate oval ( Figs 177–178 ) and in lateral view weakly convex ( Fig. 179 ); pigmentation moderately light brown; dorsum covered with extremely short whitish setae (discernible under magnification 80 ×); cuticle conspicuously glossy, on clypeus indistinctly microreticulate and only semi-matt, reticulation on remaining body parts indiscernible.

Head 0.35 mm wide; frons and vertex weakly convex, with fine, inconspicuous punctures; clypeus semi-matt; eyes large, strongly convex, coarsely faceted. Antennal club only slightly elongate.

Pronotum ( Fig. 177 ) strongly transverse, widest at base; PL 0.28 mm, PW 0.61 mm, PL/PW 0.45; lateral mar- gins 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. 178 ) with barely discernible transverse microreticulation and with fine, inconspicuous setiferous punctures; prosternal carinae slightly longer than 3/4 of prosternum and their anterior portions strongly, abruptly bent 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 0.85 mm, EW (calculated as width of the only one preserved elytron × 2) 0.80 mm, EL/EW 1.06. 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. 180 ) with distinct, sharply marked lateral longitudinal carinae bent anteromesad and not connected into anterior submarginal carina; anterior margin evenly, broadly rounded.

Metaventrite ( Fig. 180 ) 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 181–182 ) 0.30 mm long, slender; penis in ventral view slightly narrowing distad up to apical third and then broadening toward broadly rounded apex, in lateral view weakly curved; tegmen slender, much longer than half-length of penis, with slightly emarginate apex bearing one pair of long setae.

Distribution. Mascarene Islands (Rodriguez).

Remarks. The studied lectotype male is incomplete, lacking the right elytron. This specimen has conspicuously glossy cuticle, including the frons and vertex, and the microreticulation on the clypeus is also extremely fine and therefore the surface is not matt, as in the most similar M. hawaiianus . It also seems to have more distinctly marked lateral longitudinal carinae of the mesoventral plate (additionally bent anteriorly mesad; Fig. 180 ) than those in the remaining species of this group. Adventive specimens of Murmidius collected in the Great Britain and preserved at BMNH were initially identified as M. segregatus , but they almost certainly belong to another, undescribed species (see also remarks for M. stoicus ). A larger sample of this British material would be necessary to clarify this problem.

Figures

FIGURES 177–182. Morphological structures of Murmidius segregatus Waterhouse. Body in dorsal (177), ventral (178) and lateral (179) views; pterothorax in ventral view (180); and aedeagus (181–182).

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).