Murmidius drakei Heinze

Jałoszyński, Paweł & Ślipiński, Adam, 2022, Revision of the family Murmidiidae (Coleoptera: Coccinelloidea), Zootaxa 5109 (1), pp. 1-102 : 74-80

Murmidius drakei Heinze

( Figs 227–234 )

Murmidius drakei Heinze, 1944: 29 .

Type material examined. Holotype ( Paraguay): sex unknown, “ Paraguay ”, “ Dr. Drake 188”, “ Murmidius / drakei Heinze ” ( SDEI).

Additional material studied. Bolivia: 1 ex., Beni Prov., Chacobo Indian village on Rio Benicito , 66º-12º20’, under bark of old log, 28- 31.07.1960, B. Malkin leg. ( FMNH) . Brazil: 1 ex., Matto Grosso, Fecho do Tapirape , conf. of Rios Tapirape & Aranquaya, 13.12.1960, under bark, B. Malkin leg. ( FMNH) ; 1 ex., 30 km N of Barrado of Tapirape , 08.02.1964, B. Malkin leg. ( FMNH) ; 1 ex., “ Rio Caraguata , M. Grosso / Brazil III:1953 / 21º 48’; 52º

27’; 400M. alt. / Fritz Plaumann leg.” ( MIZ) . Paraguay: 1 ♂ and 2 exx of unknown sex, same data as for holotype ( SDEI) ; 2 exx, Canendiyu, Salto del Guaira, 30.10.1979 ( MHNG) ; 1 ex., San Luis , Reimoser ( NHMW) .

Emended diagnosis. Body moderately elongate oval and moderately convex, light umbra brown; antennal club only slightly elongate; anterior clypeal margin smooth; pronotum lacking lateral and sublateral longitudinal impressions; clypeus with indistinct microreticulation, glossy or only slightly matt, frons, vertex, pronotum and elytra smooth and glossy; elytra with fine and dense but inconspicuous, superficial punctures not arranged in rows; prosternal carinae about as long as 2/3 of prosternum, parallel; mesoventral plate with evenly and relatively weakly rounded anterior margin, with anterior submarginal carina broadly disrupted at middle, lacking lateral carinae; elytral epipleura not strongly narrowed at the level of metaventrite where they are much narrower than width of mesofemur; metaventrite with strong but very small, not alveolate and rather inconspicuous punctures on sides; penis slender, in lateral view strongly curved; in ventral view penis parallel-sided in proximal half and distally gradually narrowing toward subtriangular, blunt apex; tegmen slender, parallel-sided and with truncate apex bearing four pairs of moderately long setae.

Redescription. BL 1.03–1.28 mm; BL/EW 1.42–1.53. Body moderately elongate oval ( Figs 227–229 ) and in lateral view moderately convex ( Fig. 230 ); pigmentation light umbra brown; dorsum covered with extremely short whitish setae (barely discernible under magnification 80 ×); clypeus with poorly visible, very fine, semi-matt microreticulation, reticulation on remaining body parts indistinct, surface glossy.

Head 0.29–0.33 mm wide; frons and vertex weakly convex, with fine, inconspicuous punctures; clypeus semimatt; eyes large, strongly convex, coarsely faceted. Antennal club only slightly elongate ( Fig. 227 ).

Pronotum ( Figs 227–228 ) strongly transverse, widest at base; PL 0.20–0.28 mm, PW 0.53–0.65 mm, PL/PW 0.38–0.46; 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 with indistinct marginal line. Punctures on disc uniform, fine and dense, inconspicuous.

Prosternum ( Fig. 229 ) with barely discernible transverse microreticulation and with fine, inconspicuous setiferous punctures; prosternal carinae about as long as 2/3 of prosternum, parallel; notosternal carinae nerly straight and not reaching anterior prosternal margin, the latter lacking marginal carina.

Elytra ( Figs 227–228 ) together oval, with strongly rounded sides, broadest indistinctly in front of middle, EL 0.73–0.93 mm, EW 0.70–0.90 mm, EL/EW 1.03–1.07. Humerus with distinct callus; elytra densely but very finely punctate, punctures shallow, inconspicuous, not arranged in rows, those on anteromedian region of each elytron separated by spaces subequal to their diameters. Epipleura not narrowed near middle, with convex margin.

Hind wings fully developed.

Mesoventral plate ( Fig. 231 ) lacking lateral longitudinal carinae, with incomplete anterior submarginal carina broadly disrupted at middle; anterior margin evenly, broadly, but not strongly rounded.

Metaventrite ( Fig. 231 ) with deep but small, not alveolate punctures on sides; median region with fine, inconspicuous setiferous punctures. Discrimen externally poorly discernible.

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

Aedeagus ( Figs 232–234 ) 0.60 mm long, very slender; penis in ventral view parallel-sided in about proximal half, then gradually tapering towards subtriangular, blunt apex, in lateral view penis strongly curved; tegmen slen- der, parallel-sided and with truncate apex bearing four pairs of moderately long setae.

Distribution. Neotropical ( Bolivia, Brazil, Paraguay).

Remarks. Murmidius drakei is most similar to M. convexus ; see remarks for the latter species.

Genus Murmidiella gen. n.

Type species: Murmidiella sola sp. n., here designated.

Diagnosis. Body rounded and moderately convex; dorsum with extremely short, barely discernible setae; labrum exposed; clypeus with deep and narrow lateral constriction, with sides divergent anterad; antennal sulci along mesoventral margins of eyes absent; ocular carinae along dorsomesal margins of eyes present; mentum sub-pentagonal with rounded sides; ligula with nearly straight anterior margin, not bilobed; antenna composed of eight antennomeres, with subrectangular scape, antennomeres 2–7 symmetrical, penultimate antennomere subquadrate; club oval and elongate, conspicuously flat; prothoracic antennal cavities not visible in dorsal view, narrow; prosternal plate with anterior margin in lateral view weakly projecting anterad; submedian prosternal carinae present; notosternal carinae curved outwards; prosternal process about twice as wide as width of procoxa, subtrapezoidal; mesoventral plate with anterior margin weakly arcuate and lacking submarginal carina; metaventrite with discrimen externally not visible, developed on entire metaventral length; elytra with lateral margins not flattened above epipleural carinae; elytral epipleural carinae in dorsal view entirely hidden.

Description. Body of adults ( Fig. 254 ) 1.30–1.38 mm long, nearly circular in dorsal view and strongly convex ( Fig. 256 ), dark brown to nearly black, dorsum virtually asetose.

Head ( Figs 235–238 , 257 ) prognathous, strongly declining and in natural position largely retracted into protho- rax. Occiput ( Fig. 235 ; occ) strongly transverse and demarcated from frons by step-wise vertexal ridge ( Figs 235, 238 ; vr) which extends laterad on each side to connect with posterodorsal margin of each eye. Vertex ( Fig. 235 ; vt) strongly transverse and moderately convex, with posterior margin straight at middle, vertex anteriorly confluent with transverse, convex frons ( Fig. 235 ; fr); clypeus ( Figs 235, 237–238 ; cl) longer than frons and subequal in width, transverse and strongly broadening anterad so that adocular frontal region is demarcated from clypeus by deep subtriangular constriction; frontoclypeal impressed line marking site of internal ridge present, anterior margin of clypeus rounded and smooth, entire clypeus steeply declining, subvertical. Gular region demarcated from submentum and genae by fine gular ridge ( Fig. 238 ; gr) laterally extending to above middle of eye, not connecting with vertexal ridge.

Antennal fossae ( Fig. 238 ; anf) small, situated near mesal margin of each eye, not visible in dorsal view, exposed in lateral view. Antenna ( Figs 239–241 ) composed of 8 antennomeres, about as long as head; inserted in such a way that in resting position pedicel is directed ventrad and club is inserted into prothoracic antennal cavity. Scape ( Figs 235, 237, 239 ; sc) strongly enlarged, with small basal articulating ‘stalk’ inserted into antennal foramen, its distal region strongly asymmetrical and subrectangular, matching the shape of constriction at base of clypeus; pedicel ( Fig. 239 ; pd) much shorter and narrower than scape, subcylindrical and indistinctly asymmetrical; antennomeres 3–7 ( Fig. 239 ; an 3–7) each distinctly narrower than pedicel, slightly and gradually increasing in widths, symmetrical; antennomere 7 not inserted into basal cavity of club; antennal club ( Fig. 239 ; cl; Fig. 241 ) strongly flattened, oval, strongly elongate and indistinctly narrower 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 235, 237–238 , 242 ; lbr) visible externally, not covered by clypeus, strongly transverse and short, with anterolateral groups of long, thick setae and sparse, thin dorsal setae. Mandibles ( Figs 244–245 ) symmetrical, subtriangular, each with short basal region bearing massive, darkly sclerotized oval, plate-shaped mola ( Figs 244–245 ; mo) with microtuberculate surface, in resting positions molar grinding surfaces touch at middle; prostheca ( Figs 244–245 ; pst) present, membranous and in anterior half setose; distal mandibular region with three blunt teeth. Maxilla ( Figs 236 , 246 ) with semioval cardo ( Fig. 236 ; cd); basistipes ( Figs 236 , 246 ; bst) short, triangular, with group of several short setae; mediostipes ( Figs 236 , 246 ; mst) subrectangular, elongate; lacinia and galea ( Figs 236 , 246 ; lac, gal) each elongate, flat and with dense mesal and apical fringe of setae; maxillary palp tetramerous, with conspicuously small palpomere 1 ( Figs 236 , 246 ; mxp1) which is minute and inserted on poorly differentiated, elongate palpifer ( Fig. 246 ; ppf), palpomere 2 ( Figs 236 , 246 ; mxp2) large, slightly asymmetrical, weakly elongate and sparsely setose, with external margin long and rounded and mesal margin slightly shorter, also rounded, palpomere 3 ( Figs 236 , 246 ; mxp3) slightly narrower than palpomere 2, almost annulate, transverse, with several setae, palpomere 4 ( Figs 236 , 246 ; mxp4) slightly shorter than mxp2, much longer than mxp3, slightly narrowing distad and truncate at apex. Submentum ( Figs 236 , 246 ; smn) short, transverse with straight anterior margin. Mentum ( Figs 236 , 246 ; mn) at base as broad as submentum, strongly broadening anterad and near middle strongly narrowing toward relatively long and convex anterior margin, general shape subtrapezoidal with rounded sides, ventrally with median subtriangular elevation, ventral surface of mentum sparsely covered with short setae. Ligula ( Figs 236 , 246 ; lig) large subtrapezoidal with anterior margin nearly straight, with dense setae on most of its ventral and anterior surface. Labial palps inserted laterally at base of ligula, trimerous; labial palpomere 1 ( Figs 236 , 246 ; lp1) minute, weakly elongate, subcylindrical; palpomere 2 ( Figs 236 , 246 ; lp2) slightly larger than maxillary palpomere 2 and similarly shaped; palpomere 3 ( Figs 236 , 246 ; lp3) as terminal maxillary palpomere but slightly shorter.

Tentorium lacking corporatentoria, with W-shaped tentorial bridge ( Fig. 236 ; tb) bearing minute anterior median projection; posterior tentorial arms (Fig. 336; pta) fused with ventral wall of head, but posterior tentorial pits not marked; anterior tentorial arms (Fig. 336; ata) long and slender, lacking submedian lateral projections; dorsal tentorial arms ( Fig. 236 ; dta) vestigial.

Prothorax ( Figs 247–248 , 254–255 ), strongly transverse; pronotum anteriorly shallowly emarginate with projecting, obtuse-angled anterior corners; sides weakly rounded with nearly complete lateral carinae ( Fig. 248 ; lc); posterior corners distinct, obtuse-angled; pronotal base strongly projecting towards scutellar shield. Antennal cavities ( Figs 247–248 ; anc) not exposed in dorsal view, narrow and inconspicuous. Prosternum ( Fig. 247 ; pst) slightly longer than half length of prothorax, laterally fused with hypomera anteriorly, and posteriorly demarcated by straight, curved or sinuate notosternal carinae ( Figs 247–248 ; nsc) externally marking sites of reduced notosternal sutures; submedian prosternal carinae ( Fig. 247 ; psc) developed; prosternal process ( Fig. 247 ; psp) subtrapezoidal, narrowing posterad, with concave posterior margin, about as broad as twice width of procoxa. Hypomeron ( Fig. 247 ; hy) broad and weakly impressed, with well-defined postcoxal process. Prosternum with a pair of distinct glandular openings in anterior 2/3 (well-visible in Fig. 255 ) leading to long subcuticular tubular ducts with cluster of elongate reservoirs ( Fig. 247 ). Profurcal arms ( Fig. 247 ; pf) long, profurcal foveae not visible externally.

Fore legs ( Fig. 247 ) with subglobose coxae; elongate and subtriangular trochanters; broad, short and dorsoventrally flattened femora; tibiae about as long as femora, gradually broadening distad and with external subapical elongate flattened expansion; tarsi subcylindrical, much longer than half length of tibia, with tarsomere 4 about as long as 1; tarsal claws long

Mesonotum ( Fig. 249 ) with strongly transverse mesoscutum ( Fig. 249 ; sc2) and mesoscutellum ( Fig. 249 ; scl2) demarcated by weakly marked scutoscutellar suture; mesoscutellum with strongly sclerotized scutellar shield ( Fig. 249 ; scs), its posteromedian triangular portion exposed between elytral bases.

Elytra ( Fig. 252 ) together suboval with truncate bases; epipleura partly visible in lateral view and demarcated from elytral disc by complete, sharp carina not visible in dorsal view; elytral apex with ventral field of cuticular projections arranged in rows, interlocking with crenulation of abdominal ventrite 5. Elytral punctures arranged in irregular, poorly marked rows.

Mesoventrite ( Fig. 251 ; v 2 ) with transverse, approximately hexagonal posteromedian mesoventral plate ( Fig. 251 ; mvp) with its posterior margin in dry-mounted specimens poorly marked or indiscernible, plate without anterior submarginal carina and lateral carinae; 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. 251 artificially ‘unfolded’ laterad).

Middle legs ( Fig. 251 ) with subglobose coxae; elongate, subtriangular trochanters; broad and short, flattened dorso-ventrally femora; tibiae about as long as femora, gradually thickening distad, with subapical external flattening; tarsi subcylindrical, much longer than half length of tibia, tarsomere 4 about as long as 1–2 combined, tarsal claws long.

Metanotum ( Fig. 250 ) with large metascutum ( Fig. 250 ; sc3) divided at middle by median membranous area ( Fig. 250 ; mma); alacristae ( Fig. 250 ; alc) complete; postnotum ( Fig. 250 ; pn3) short, with rounded posterior margin.

Hind wings (not shown) well-developed and functional.

Metaventrite ( Fig. 251 ; v 3 ) strongly transverse, with entire discrimen ( Fig. 251 ; dsc) in dry-mounted specimens not discernible externally; sides with metaventral femoral lines ( Fig. 251 ; mfl) mesally and posteriorly demarcating impressed mesofemoral rests; posteromedian margin of metaventrite nearly straight. Metanepisterna ( Fig. 251 ; aest3) and metepimera (not shown) narrow, in natural position subvertical.

Metendosternite with elongate, divergent metafurcal arms ( Fig. 251 ; mtfa), each with additional submedian lateral projection, each arm ending with small plate for muscle attachment close to posterior margin of metanotum.

Hind legs ( Fig. 251 ) with transverse, weakly convex and suboval coxae; elongate, subtriangular trochanters; broad and short, flattened dorso-ventrally femora; tibiae slightly longer than femora, gradually thickening distad and with subapical external flattening; tarsi subcylindrical, distinctly longer than half length of tibia, tarsomere 4 about as long as 1, tarsal claws long.

Abdomen ( Fig. 253 ) with five visible ventrites, of which first is as about as long as 2–4 combined and bears abdominal femoral lines ( Fig. 253 ; 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 unknown.

Immature stages. Unknown.

Composition and distribution. Monotypic genus known to occur in Ecuador.

Remarks. This genus seems extremely rare, as only four specimens were found in over twenty surveyed collections, including the largest world museums. All four available specimens are females and were collected by insecticidal fogging of trees. Therefore, chances to find a male seem low and for this reason we decided to describe this peculiar taxon based on females. Murmidiella seems important to reconstruct the evolution of Murmidiidae and to understand their relationships with other coccinelloid families.

Figures

FIGURES 227–234. Morphological structures of Murmidius drakei Heinze. Body in dorsal (227–228), ventral (229) and lateral (230) views; pterothorax in ventral view (231); penis (232–233), and apical region of tegmen (234).

FIGURES 254–258. Morphological structures of Murmidiella sola gen. & sp. n. Body in dorsal (254), ventral (255) and lateral (256) views; head in anterior view (257); and pterothorax in ventral view (258).

FIGURES 235–241. Morphological structures of Murmidiella sola gen. & sp. n. Head in dorsal (235), ventral (236), anterior (237) and lateral (238) views; antenna in dorsal (239) and lateral (240) views, and antennal club (241). Abbreviations: an3–7, antennomere 3–7; anf, antennal fossa; ata, anterior tentorial arm; bst, basistipes; cd, cardo; cl, clypeus; clb, antennal club; dta, dorsal tentorial arm; fr, frons; gal, galea; gr, gular ridge; lac, lacinia; lbr, labrum; lig, ligula; lp1–3, labial palpomere 1–3; md, mandible; mn, mentum; mst, mediostipes; mxp1–4, maxillary palpomere 1–4; oc, ocular carina; occ, occiput; pd, pedicellus; pta, posterior tentorial arm; sc, scapus; smn, submentum; tb, tentorial bridge; vr, vertexal ridge; vt, vertex.

FIGURES 242–246. Morphological structures of Murmidiella sola gen. & sp. n. Labrum in dorsal view (242); labial-maxillary complex in ventral view (243); mandible in dorsal (244) and mesal (245) views; maxilla in ventral view (246). Abbreviations: bst, basistipes; eps, epipharyngeal scaffold; gal, galea; lac, lacinia; lp1–3, labial palpomere 1–3; mn, mentum; mo, mola; mst, mediostipes; mxp1–4, maxillary palpomere 1–4; ppf, palpifer; pst, prostheca; smn, submentum; tr, torma.

FIGURES 247–253. Morphological structures of Murmidiella sola gen. & sp. n. Prothorax in ventral (247) and lateral (248) views; mesonotum in dorsal view (249); metanotum in dorsal view (250); pterothorax in ventral view (251); right elytron in dorsal view (252); abdomen in ventral view (253). Abbreviations: aest2–3, meso- and metanepisternum; afl, abdominal femoral line; alc, alacrista; anc, antennal cavity; av1–5, abdominal ventrite 1–5; dsc, discrimen; epm2, mesepimeron; hy, hypomeron; lc, lateral carina; mfl, metaventral femoral line; mma, median membranous area; mtfa, metafurcal arm; mvp, mesoventral plate; nsc, notosternal carina; pf, profurcal arm; pn3, metapostnotum; psc, prosternal carina; psp, prosternal process; pst, prosternum; sc2– 3, meso- and metascutum; scl2, mesoscutellum; scs, scutellar shield; smc, submarginal carina; v2–3, meso- and metaventrite.

FIGURES 1–7. Morphological structures of Botrodus montserratensis sp. n. Head in dorsal (1), ventral (2), anterior (3) and lateral (4) views; antenna in dorsal view (5); mandibles in dorsal (6) and mesal (7) views. Abbreviations: an3–7, antennomere 3–7; anf, antennal fossa; ans, antennal sulcus; ata, anterior tentorial arm; bst, basistipes; cd, cardo; cl, clypeus; clb, antennal club; dta, dorsal tentorial arm; fr, frons; gal, galea; gr, gular ridge; lac, lacinia; lbr, labrum; lig, ligula; lp1–3, labial palpomere 1–3; md, mandible; mn, mentum; mo, mola; mst, mediostipes; mxp1–4, maxillary palpomere 1–4; occ, occiput; pd, pedicellus; pst, prostheca; pta, posterior tentorial arm; sc, scapus; smn, submentum; tb, tentorial bridge; vr, vertexal ridge; vt, vertex.