Mychocerinus pilifer (Lewis)

Jałoszyński, Paweł & Ślipiński, Adam, 2022, Revision of the family Murmidiidae (Coleoptera: Coccinelloidea), Zootaxa 5109 (1), pp. 1-102 : 96-98

Mychocerinus pilifer (Lewis)

( Figs 298–304 )

Mychocerus pilifer Lewis, 1888: 244 .

Mychocerinus pilifer: Slipinski, 1990: 85 .

Type material examined. Lectotype [here designated by A. Ślipiński] ( Mexico): sex unknown, “Type” “El Reposo, 800ft / Champion”, “Mychocerus / pilifer / Type / Lewis” [left specimen of two mounted on single card] ( BMNH) . Paralectotypes (3 exx): 3 exx, sex unknown, same data as for lectotype ( BMNH) .

Additional material studied. Mexico: 2 exx, Oaxaca, Matjas Romen , 03.06.1975, D.S. Chandler leg. ( FSCA), 1 ♂ , Veracruz, Tezonapa , 08.08.1941, H.S. Dybas leg. ( FMNH) .

Emended diagnosis. Body elongate oval, uniformly light brown; dorsal pubescence recumbent and relatively dense; pronotum weakly narrowing from base, with distinct punctures distributed only on sides where they reach lateral carinae, median region virtually impunctate; elytral punctures fine on anteromedian adsutural region but distinct and moderately dense on sides, in longitudinal rows separated by spaces 1‒2 × their diameters; posterior regions of lateral longitudinal carinae of mesoventral plate forming an angle of ~20 degree with longitudinal body axis; parameres slender, ~3 times as long as broad, with setae only on their distal halves.

Redescription. BL 1.05 mm; BL/EW 1.45. Body moderately elongate oval ( Figs 298–300 ) and in lateral view weakly convex ( Fig. 301 ), with highest site situated near middle of elytra; pigmentation light brown; dorsum covered with short yellowish recumbent and relatively short setae; clypeus with very fine but distinct microreticulation, semi-matt, reticulation on remaining body parts present but superficial and very fine, indistinct.

Head 0.30 mm wide; frons and vertex weakly convex, distinct punctures distributed mainly on sides of vertex, shallow, separated by spaces subequal to their diameters; clypeus semi-matt; eyes large, strongly convex, coarsely faceted.

Pronotum ( Figs 298‒299 ) strongly transverse, broadest at base; PL 0.25 mm, PW 0.55 mm, PL/PW 0.45; lateral margins weakly rounded in posterior half and more strongly so in anterior half, where they are strongly converging anterad; lateral carinae narrow but distinct; anterior pronotal margin lacking marginal line. A pair of large, very shallow, diffuse and oval submedian impressions is present in posterior half of disc. Punctures on disc unevenly distributed, moderately large, distinct punctures are present on sides and reach lateral pronotal carinae, median area virtually impunctate; punctures on sites where they are most distinct are separated by spaces as wide as 1‒2 their diameters.

Prosternum ( Fig. 300 ) with distinct microreticulation and with fine, inconspicuous setiferous punctures; prosternal carinae about as long as 3/4 of prosternum, indistinctly arcuate, slightly convex mesally; notosternal carinae slightly curved outwards and not reaching anterior prosternal margin, the latter lacking marginal carina and relatively shallowly emarginate.

Elytra ( Figs 298–299 ) together oval, with moderately strongly rounded sides, broadest near anterior third, EL 0.73 mm, EW 0.73 mm, EL/EW 1.00. Humerus with distinct callus; elytral punctures on large anteromedian adsu- tural region very small and shallow and partly arranged in longitudinal rows, those on side of each elytron moderately large but distinct, sharply marked, and partly arranged in irregular, not very distinct longitudinal rows, most punctures relatively dense, separated by spaces as wide as 1‒2 × their diameters.

Hind wings fully developed.

Mesoventral plate ( Fig. 302 ) with posterior portions of lateral longitudinal carinae forming an angle of ~20 degree with longitudinal body axis, and junction with metaventral femoral line is rounded; anterior margin of mesoventral plate straight or nearly so.

Metaventrite ( Fig. 302 ) with distinct, dense and numerous punctures on sides; median region with fine, inconspicuous setiferous punctures. Discrimen externally poorly marked.

Aedeagus ( Figs 291–292 ) 0.28 mm long, moderately slender; penis in lateral view almost evenly, curved; tegmen slender, narrowing from base toward apex, with relatively slender, subtriangular parameres which are about ~2.5‒3 times as long as broad (especially slender in lateral view) and each bears 4 long setae distributed from middle to apex.

Distribution. Southern Mexico.

Remarks. Mychocerinus pilifer is externally most similar to M. depressus ; see remarks for the latter species. Larger material is necessary to clarify the status of M. pilifer ; it may in fact be identical with M. depressus , as the external and genital differences seem rather minor. With a limited material at hand, we were not able to unambiguously clarify this problem.

Figures

FIGURES 298–304. Morphological structures of Mychocerinus pilifer (Lewis). Body in dorsal (298–299), ventral (300) and lateral (301) views; pterothorax in ventral view (302); and aedeagus (303–304).

FIGURES 286–292. Morphological structures of Mychocerinus depressus (LeConte). Body in dorsal (286–287), ventral (288) and lateral (289) views; pterothorax in ventral view (290); and aedeagus (291–292).