Murmidiella sola, Jałoszyński & Ślipiński, 2022
treatment provided by
Murmidiella sola sp. n.
Type material examined. Holotype ( Ecuador): ♀, “ Ecuador: Napo, Res. Ethnica / Waorani, 1 km S. Onkone Gare / Camp , Trans. Ent. 20 June 1996 / 220m. 00º39’10’’S, 076º26’W / T. L. Erwin, et al. collectors”, “Insecticidal fog- ging of mostly bare / green leaves, some with covering / of lichenous or bryophytic plants in / terre firme forest. At Trans. 1, / Sta. 3 Project MAXUS Lot 1523” ( USNM) GoogleMaps . Paratypes: 3 ♀♀ (2 disarticulated), same data as for holotype ( USNM) GoogleMaps .
Diagnosis. As for genus; vide supra.
Description. BL 1.30–1.38 mm; BL/EW 1.26–1.27. Body nearly circular ( Figs 254–255 View FIGURES 254–258 ) and in lateral view strongly convex ( Fig. 256 View FIGURES 254–258 ); pigmentation dark brown, legs slightly lighter; dorsum with extremely short, barely discernible setae; microreticulation on clypeus distinct and matt, on frons and vertex much finer and superficial, semi-matt, pronotum and elytra smooth and glossy.
Head 0.38–0.39 mm wide; frons and vertex weakly convex, with small but sharply marked punctures ( Fig. 257 View FIGURES 254–258 ) separated by spaces subequal to their diameters; clypeus matt; eyes large, strongly convex, coarsely faceted. Antennal club about twice as long as broad.
Pronotum ( Fig. 254 View FIGURES 254–258 ) strongly transverse, widest at base; PL 0.28 mm, PW 0.78–0.89 mm, PL/PW 0.31–0.35; lateral margins weakly rounded and very strongly convergent anterad, with very fine lateral carinae; anterior pronotal margin with very fine, barely discernible marginal line. Punctures on disc ( Fig. 257 View FIGURES 254–258 ) as small and distinct as those on frons and vertex but much sparser and slightly unevenly distributed, those on median area separated by spaces 1.5‒2 × their diameters.
Prosternum ( Fig. 255 View FIGURES 254–258 ) with distinct, mostly transverse microreticulation and with fine, inconspicuous setiferous punctures; near anterior 2/3 with a pair of small glandular openings; prosternal carinae about as long as half-length of prosternum and each accompanied by a longitudinal row of densely distributed, large circular and shallow alveolate punctures; notosternal carinae curved outwards, not reaching anterior prosternal margin, the latter with narrow but distinct marginal carina.
Elytra ( Figs 254, 256 View FIGURES 254–258 ) together oval, with strongly rounded sides, broadest near anterior 1/3, EL 0.90–0.98 mm, EW 1.03–1.09 mm, EL/EW 0.88–0.90. Humerus with distinct callus; elytra with shallow but well-discernible punc- tures arranged into partly irregular, not very distinct longitudinal rows, more distinct on sides, punctures reducing in diameters and depth toward elytral apices. Epipleura ( Fig. 255 View FIGURES 254–258 ) broad and unmodified, at the level of middle of metaventrite slightly narrower than width of mesofemur.
Hind wings fully developed.
Mesoventral plate ( Fig. 258 View FIGURES 254–258 ) lacking lateral longitudinal carinae and anterior submarginal carina; anterior margin evenly rounded; surface with sparse and shallow circular or oval alveolate punctures distributed along anterior margin and on sides.
Metaventrite ( Figs 255, 258 View FIGURES 254–258 ) with similar alveolate punctures as those on mesoventral plate distributed on sides, median region smooth with a pair of slightly elevated strips of cuticle covered with fine longitudinal microsculpture and forming an inversed V-shaped structure ( Fig. 258 View FIGURES 254–258 ). Discrimen externally not visible.
Tarsi with moderately long setae on tarsomeres 1–3 ( Fig. 255 View FIGURES 254–258 ).
Distribution. Neotropical ( Ecuador).
Genus Mychocerinus Ślipiński
Mychocerus LeConte, 1869: 255. Type species: Murmidius depressus LeConte, 1866 (by monotypy); preoccupied, not Mycho- cerus Erichson, 1845: 293.
Emended diagnosis. Body elongate oval; distinctly flattened; dorsum with dense setae; labrum exposed; clypeus subrectangular, not broadening anterad or indistinctly broadening; antennal sulci along mesoventral margins of eyes present; ocular carinae along dorsomesal margins of eyes lacking; mentum subhexagonal with distinctly angulate sides; ligula distinctly cordiform but not bilobed; antenna composed of nine antennomeres, with unmodified, subconical scape and not elongate penultimate antennomere; antennomeres 4–6 slightly asymmetrical, with mesal margins expanded; prothoracic antennal cavities not visible in dorsal view; prosternal plate with anterior margin in lateral view not projecting beyond level of anterior margin of pronotum; submedian prosternal carinae present; notosternal carinae curved outwards or sinuate; prosternal process about three times as broad as procoxa, subtrapezoidal or subrectangular, strongly transverse; mesoventral plate with anterior margin straight or indistinctly convex and lacking submarginal carina; metaventrite with discrimen externally not discernible but complete, extending from posterior margin of mesoventrite nearly to posterior margin of metaventrite; elytra with lateral margins strongly flattened above epipleural carinae; elytral epipleural carinae entirely exposed in dorsal view; elytral punctures at least partly arranged in longitudinal rows; tegmen with well developed, articulated and elongate parameres, ~ times as long as broad at base, in all species with not only apical, but also subapical and often also basal setae along external margins.
Redescription. Body of adults 0.93–1.3 mm long, stout, flattened and strongly rounded laterally, light to dark brown, cuticle not very glossy and covered with short but dense setae well-visible under stereomicroscope.
Head ( Figs 259–262 View FIGURES 259–265 ) prognathous, not declining or indistinctly declining in natural position. Occiput ( Fig. 259 View FIGURES 259–265 ; occ) strongly transverse and demarcated from frons by step-wise vertexal ridge ( Figs 259, 262 View FIGURES 259–265 ; vr) which extends laterad on each side where it becomes weaker and disappears near 1/3 of head height ( Fig. 262 View FIGURES 259–265 ). Vertex ( Fig. 259 View FIGURES 259–265 ; vt) strongly transverse and moderately convex, with posterior margin anteriorly indistinctly concave, vertex anteriorly confluent with strongly transverse, convex frons ( Fig. 259 View FIGURES 259–265 ; fr); clypeus ( Figs 259, 261–262 View FIGURES 259–265 ; cl) nearly as long as but much narrower than frons, subrectangular and transverse, demarcated by distinct impressed frontoclypeal line marking site of internal ridge, sides of clypeus not constricted or only indistinctly divergent anterad, anterior margin weakly convex or straight, entire clypeus weakly declining. Gular region demarcated from submentum and genae by fine gular ridge ( Figs 260, 262 View FIGURES 259–265 ; gr) laterally extending to nearly middle of head height and posteriorly demarcating broad antennal sulcus ( Figs 260, 262 View FIGURES 259–265 ; ans).
Antennal fossae ( Figs 261–262 View FIGURES 259–265 ; anf) small, situated near mesal margin of each eye, not visible in dorsal view, exposed in lateral view. Antenna ( Fig. 263 View FIGURES 259–265 ) composed of 9 antennomeres, only slightly longer than head; inserted in such a way that in resting position pedicel is directed ventrad and distal portion of recurved antenna rests in antennal sulcus, with club inserted into prothoracic antennal cavity. Scape ( Fig. 263 View FIGURES 259–265 ; sc) strongly enlarged, with small subbasal and sublateral ‘stalk’ inserted into antennal foramen, subconical and indistinctly asymmetrical; pedicel ( Fig. 263 View FIGURES 259–265 ; pd) shorter and much narrower than scape, subcylindrical with slightly asymmetrical base; antennomeres 3–8 ( Fig. 263 View FIGURES 259–265 ; an 3–8) each much narrower than pedicel, of unequal width, and slightly asymmetrical, especially antennomere 6 slightly enlarged and with mesal margin expanding; antennomere 8 ( Fig. 263 View FIGURES 259–265 ; an8) subquadrate, never elongate; antennal club ( Fig. 263 View FIGURES 259–265 ; clb) oval, elongate and as broad as or indistinctly broader than scape, with slightly more than basal half showing transverse annulate microsculpture and distal portion lacking microsculpture but with uneven, slightly granulate surface and bearing several strongly elongate basiconic sensilla in addition to setae.
Labrum ( Figs 259, 261–262 View FIGURES 259–265 ; lbr) exposed, strongly transverse and much shorter than clypeus, with dense and irregularly distributed dorsal setae. Mandibles ( Figs 264–265 View FIGURES 259–265 ) symmetrical, subtriangular, each with short basal region bearing massive, darkly sclerotized oval, plate-shaped mola ( Figs 264–265 View FIGURES 259–265 ; mo) with microtuberculate surface, in resting positions molar grinding surfaces touch at middle ( Fig. 261 View FIGURES 259–265 ); prostheca ( Figs 264–265 View FIGURES 259–265 ; pst) present, membranous and in anterior half setose; distal mandibular region with three blunt teeth; external mandibular margin with several short erect setae. Maxilla ( Fig. 260 View FIGURES 259–265 ) with semioval cardo ( Fig. 260 View FIGURES 259–265 ; cd); basistipes ( Fig. 260 View FIGURES 259–265 ; bst) short, triangular; mediostipes ( Fig. 260 View FIGURES 259–265 ; mst) subrectangular; lacinia and galea (not shown) each elongate, flat and with dense mesal and apical fringe of setae; maxillary palp tetramerous, with conspicuously small palpomere 1 ( Fig. 260 View FIGURES 259–265 ; mxp1) which is minute and inserted on poorly differentiated palpifer, palpomere 2 ( Figs 260 View FIGURES 259–265 , 214 View FIGURES 213–219 ; mxp2) large, asymmetrical, with external margin convex, angulate and long and mesal margin concave or straight and short, weakly elongate and sparsely setose, palpomere 3 ( Figs 260, 262 View FIGURES 259–265 ; mxp3) much smaller than palpomere 2, subcylindrical and transverse, with several setae, palpomere 4 ( Figs 260, 262 View FIGURES 259–265 ; mxp4) only slightly shorter than mxp2 and much longer than mxp3, slightly narrowing distad and truncate at apex, with one seta. Submentum ( Fig. 260 View FIGURES 259–265 ; smn) short, transverse with straight anterior margin. Mentum ( Fig. 260 View FIGURES 259–265 ; mn) at base as broad as submentum, strongly broadening anterad and near middle rapidly, strongly narrowing toward short and concave anterior margin, general shape hexagonal with lateral margins in posterior half convex, and in anterior half concave, ventral surface sparsely covered with short setae. Ligula ( Fig. 260 View FIGURES 259–265 ; lig) large and cordiform but not bilobed, with dense setae on anterior half. Labial palps inserted laterally at base of ligula, trimerous; labial palpomere 1 ( Fig. 260 View FIGURES 259–265 ; lp1) minute, indistinctly elongate, subcylindrical; palpomere 2 ( Fig. 260 View FIGURES 259–265 ; lp2) nearly as large as maxillary palpomere 2 and similarly shaped; palpomere 3 ( Fig. 260 View FIGURES 259–265 ; lp3) as terminal maxillary palpomere but distinctly smaller.
Tentorium lacking corporatentoria, with W-shaped tentorial bridge ( Fig. 260 View FIGURES 259–265 ; tb) bearing anterior median projection; posterior tentorial arms ( Fig. 260 View FIGURES 259–265 ; pta) fused with ventral wall of head, and posterior tentorial pits ( Fig. 260 View FIGURES 259–265 ; ptp) visible at least in some specimens; anterior tentorial arms ( Fig. 260 View FIGURES 259–265 ; ata) long and slender, each with small angulate lateral expansion near middle.
Prothorax ( Figs 266‒267 View FIGURES 266–271 ) strongly transverse; pronotum anteriorly shallowly emarginate with relatively strong- ly projecting, subtriangular and obtuse-angled anterior corners; sides rounded with complete lateral carinae ( Fig. 267 View FIGURES 266–271 ; lc); posterior corners distinct, slightly obtuse-angled or nearly right; pronotal base strongly projecting towards scutellar shield. Antennal cavities ( Figs 266–267 View FIGURES 266–271 ; anc) large but not visible in dorsal view. Prosternum ( Fig. 266 View FIGURES 266–271 ; pst) much longer than half length of prothorax, laterally fused with hypomera anteriorly, and posteriorly demarcated by sinuate notosternal carinae ( Figs 266–267 View FIGURES 266–271 ; nsc) externally marking sites of reduced notosternal sutures; submedian prosternal carinae ( Fig. 266 View FIGURES 266–271 ; psc) present in all species; prosternal process ( Fig. 266 View FIGURES 266–271 ; psp) subtrapezoidal or subrectangular, strongly transverse, with weakly concave posterior margin, as broad as three widths of procoxa. Hypomeron ( Fig. 266 View FIGURES 266–271 ; hy) broad and weakly impressed, with well-defined postcoxal process. Profurcal arms (not shown) long, profurcal foveae not visible externally.
Fore legs ( Fig. 266 View FIGURES 266–271 ) with subglobose coxae; elongate and subtriangular trochanters; broad, short and dorsoventrally flattened femora; tibiae only slightly longer than femora, gradually broadening distad; tarsi subcylindrical, distinctly longer than half length of tibia, with tarsomere 4 longer than 1–3 combined; tarsal claws long
Mesonotum ( Fig. 268 View FIGURES 266–271 ) with strongly transverse mesoscutum ( Fig. 268 View FIGURES 266–271 ; sc2) and mesoscutellum ( Fig. 268 View FIGURES 266–271 ; scl2) demarcated by weakly marked scutoscutellar suture; mesoscutellum with strongly sclerotized scutellar shield ( Fig. 268 View FIGURES 266–271 ; scs), its posteromedian triangular portion exposed between elytral bases.
Elytra ( Fig. 270 View FIGURES 266–271 ) together suboval with truncate bases; epipleura visible in lateral view and demarcated from elytral disc by complete, sharp epipleural carina which is entirely or almost entirely visible in dorsal view, narrow supra-epipleural region of each elytron strongly flattened; elytral apex with ventral field of cuticular projections arranged in rows, interlocking with crenulation of abdominal ventrite 5. Elytral punctures at least partly arranged in distinct rows.
Mesoventrite ( Fig. 269 View FIGURES 266–271 ; v 2 View FIGURES 1–7 ) with transverse, hexagonal posteromedian mesoventral plate ( Fig. 269 View FIGURES 266–271 ; mvp) with its posterior margin in most dry-mounted specimens poorly marked, plate lacking anterior submarginal carina; mesoventrite in front of plate situated more dorsally, interlocking with prothorax in such a way that in natural position prosternal process and procoxae overlap anterior portion of mesoventrite and medially tightly fit to anterior margin of mesoventral plate. Mesanepisterna and mesepimera large, in natural position subvertical (in Fig. 269 View FIGURES 266–271 artificially ‘unfolded’ laterad).
Middle legs ( Fig. 269 View FIGURES 266–271 ) with subglobose coxae; elongate, subtriangular trochanters; broad and short, flattened dorso-ventrally femora; tibiae relatively slender, slightly longer than femora, gradually and weakly thickening distad; tarsi subcylindrical, distinctly longer than half length of tibia, tarsomere 4 longer than 1–3 combined, tarsal claws long.
Metanotum ( Fig. 268 View FIGURES 266–271 ) with large metascutum ( Fig. 268 View FIGURES 266–271 ; sc3) divided at middle by median membranous area ( Fig. 268 View FIGURES 266–271 ; mma); alacristae ( Fig. 268 View FIGURES 266–271 ; alc) complete; postnotum ( Fig. 268 View FIGURES 266–271 ; pn3) transverse, with rounded posterior margin.
Hind wings (not shown) well-developed and functional in all nominal species.
Metaventrite ( Fig. 269 View FIGURES 266–271 ; v 3 View FIGURES 1–7 ) strongly transverse, with entire discrimen ( Fig. 269 View FIGURES 266–271 ; dsc) which is not marked externally in most studied specimens; sides with metaventral femoral lines ( Fig. 269 View FIGURES 266–271 ; mfl) mesally and posteriorly demarcating impressed mesofemoral rests; posteromedian margin of metaventrite straight or nearly so. Metanepisterna ( Fig. 269 View FIGURES 266–271 ; aest3) and metepimera (not shown) narrow, in natural position subvertical.
Metendosternite with elongate, divergent metafurcal arms ( Fig. 269 View FIGURES 266–271 ; mtfa), each with additional submedian lateral projection, each arm ending with small plate for muscle attachment close to middle of metaventrite.
Hind legs ( Fig. 269 View FIGURES 266–271 ) with transverse, weakly convex and drop-shaped coxae; elongate, subtriangular trochan- ters; broad and short, flattened dorso-ventrally femora; tibiae relatively slender, slightly longer than femora, gradually and weakly thickening distad; tarsi subcylindrical, distinctly longer than half length of tibia, tarsomere 4 about as long as 1–3 combined, tarsal claws long.
Abdomen ( Fig. 271 View FIGURES 266–271 ) with five visible ventrites, of which first is as long (or nearly so) as 2–4 combined and bears abdominal femoral lines ( Fig. 271 View FIGURES 266–271 ; afl) bordering slightly impressed metafemoral rests; ventrite 5 with posterior margin crenulate, bearing transverse row of peg-like cuticular projections interlocking with ventral apical trichial fields of each elytron.
Aedeagus (e.g., Figs 284–285 View FIGURES 279–285 ) with tubular penis, sheath-like tegmen with elongate median strut and a pair of elongate articulated parameres (articulation in one species poorly marked) with apical and subapical setae, in some species also basal setae.
Immature stages. Unknown.
Composition and distribution. Six nominal species are distributed in New Caledonia, Hawaiian Islands, USA (Arizona, Eastern North America from southern Ontario south to Florida and west to eastern Texas), Mexico, Guatemala, Argentina (see also remarks).
Remarks. Very rare genus in surveyed collections. Adults have been collected under bark of various trees, often infested by fungi. There are two further species (found in Paraguay and Samoa) which are left undescribed due to the lack of sufficient material and distinctive external features.
1 - 2
- 4 - 5
- Dorsum with suberect pubescence ( Figs 282 View FIGURES 279–285 , 308 View FIGURES 305–311 )........................................................... 2 Dorsum with recumbent pubescence ( Figs 275 View FIGURES 272–278 , 289 View FIGURES 286–292 , 294 View FIGURES 293–297 , 301 View FIGURES 298–304 )................................................. 3 Body nearly circular ( Fig. 305 View FIGURES 305–311 ) and in lateral view with the highest site situated near middle of elytra ( Fig. 308 View FIGURES 305–311 ); elytra darker than pronotum ( Fig. 305 View FIGURES 305–311 ); flattened sides of pronotum lacking large punctures ( Fig. 306 View FIGURES 305–311 ); rows of punctures on elytra indistinct, even on outer half composed of small and sparse punctures separated by spaces over 3‒4 times wider than their diameters ( Fig. 306 View FIGURES 305–311 ); sides of metaventrite with about a dozen sparse punctures ( Fig. 309 View FIGURES 305–311 )......... M. oahuanus sp. n. [Hawaiian Islands] Body shortly elongate ( Fig. 279 View FIGURES 279–285 ) and in lateral view with the highest site situated clearly behind middle of elytra ( Fig. 282 View FIGURES 279–285 ); elytra not darker than pronotum ( Fig. 279 View FIGURES 279–285 ); flattened sides of pronotum covered with large punctures ( Fig. 280 View FIGURES 279–285 ); rows of punctures on elytra distinct at least in outer half, where large punctures are separated by spaces equal to or narrower than their diameters ( Fig. 280 View FIGURES 279–285 ); sides of metaventrite with about three dozens densely distributed punctures ( Fig. 283 View FIGURES 279–285 ).......................
.................................................................... M. caledonicus sp. n. [ New Caledonia] Lateral pronotal margins parallel in posterior half or slightly more ( Fig. 271 View FIGURES 266–271 ).......................................
.......................................... M. arizonensis Lawrence & Stephan [ USA: Arizona; Mexico: Sonora] Lateral pronotal margins narrowing anterad from base ( Figs 292 View FIGURES 286–292 , 297 View FIGURES 293–297 , 285 View FIGURES 279–285 )....................................... 4 Body dark brown............................................................... M. piceus sp. n. [ Argentina] Body light brown...................................................................................... 5 Parameres in lateral view slender, about 3 times as long as broad, with setae on distal half ( Fig. 303 View FIGURES 298–304 ).....................
................................................................... M. pilifer (Lewis) [ Guatemala, Mexico] Parameres in lateral view stout, about 1.5 times as long as broad, with setae distributed from near base ( Fig. 291 View FIGURES 286–292 ). ..........
.................................................................... M. depressus (LeConte) [eastern USA]
Tavera, Department of Geology and Geophysics
Smithsonian Institution, National Museum of Natural History
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