Morphostenophanes Pic, 1925

Zhou, De-Yao, 2020, A revision of the genus Morphostenophanes Pic, 1925 (Coleoptera, Tenebrionidae, Stenochiinae, Cnodalonini), Zootaxa 4769 (1), pp. 1-81 : 6-9

publication ID	https://doi.org/ 10.11646/zootaxa.4769.1.1
publication LSID	lsid:zoobank.org:pub:A827EDA4-F0AF-4BCE-AF5E-4DF0475E42CD
DOI	https://doi.org/10.5281/zenodo.3815917
persistent identifier	https://treatment.plazi.org/id/7F3D8795-4A1C-FFAE-FF5A-FF5C6D7F92E5
treatment provided by	Plazi
scientific name	Morphostenophanes Pic, 1925
status

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Morphostenophanes Pic, 1925 ẎȐAEƤṚ

Morphostenophanes Pic, 1925: 7 . Type species: Morphostenophanes aenescens Pic, 1925 , by original designation. Promorphostenophanes Kaszab, 1960: 277 . Type species: Promorphostenophanes atavus Kaszab, 1960 , by original designa-

tion. Also misspelled Pseudomorphostenophanes in one figure caption of Kaszab 1980: 218.

Description. Body elongate, gourd-shaped, medium to large sized (ca. 12.0–27.0 mm long).

Head hypognathus, narrower than pronotum, and widest across middle of eyes; without visible membrane between labrum and clypeus; clypeus transverse, nearly hexagonal, with straight to emarginate anterior margin, usually with transverse clypeal impression ( Fig. 1A View FIGURE 1 ; cti) before frontoclypeal suture, frontoclypeal suture well developed, broadly U-shaped; genae strongly raised, depressed before eyes, roundly produced anterolaterally; eyes transversely reniform, strongly protruding; inner ocular sulci weakly depressed to shallowly grooved; frons broad, smooth or faintly wrinkled, sometimes with paired frontal impressions ( Fig. 1A View FIGURE 1 ; fi), paired vertexal lateral impressions ( Fig. 1A View FIGURE 1 ; vli) and vertexal median impression ( Fig. 1A View FIGURE 1 ; vmi). Labrum ( Fig. 1C View FIGURE 1 ) transverse, elongate oval, anterior margin emarginate, bearing serried setae; Mandibles ( Figs. 1D, E View FIGURE 1 ) truncate, apex bidentate in most species, prosthecae ( Fig. 1D, E View FIGURE 1 ; pst) broad, membranous. Maxilla ( Fig. 1G View FIGURE 1 ) with galea ( Fig. 1G View FIGURE 1 ; gal) long and straight, with long and dense bristles; lacinia ( Fig. 1G View FIGURE 1 ; lac) straight, well-developed, clearly separated from mediostipes ( Fig. 1G View FIGURE 1 ; mst), with dense long bristles along inner margin, basistipes ( Fig. 1G View FIGURE 1 ; bst) sometimes depressed in middle. Gula with posterior tentorial pits marked ( Fig. 16F View FIGURE 16 ; ptp). Labium ( Fig. 1F View FIGURE 1 ) with submentum fused with hypostoma, lateral suture of submentum faintly presented; mentum ( Fig. 1F View FIGURE 1 ; mn) with medial surface with several large pores bearing long setae, gradually rising anteriorly, depressed along both sides; prementum ( Fig. 1F View FIGURE 1 ; pmn) strongly emarginate; glossa ( Fig. 1F View FIGURE 1 ; gl) flabellate, emarginate, with a pair of lobes densely pubescent anteriorly; labial palpi short; with palpomere II and palpomere III ( Fig. 1F View FIGURE 1 ; lp2, lp3) each dilated distally. Antennae slender, antennomeres elongate, and gradually thickening distally. Antennomere XI oblong-oval or fusiform, antennomeres V–XI pubescent, last five antennomeres with stellate sensoriae.

Pronotum with marginal borders around entire outline, anterior marginal border occasionally obscured in middle; posterior portions of lateral marginal borders obscured in dorsal view; pronotal disc convex, usually with a pair of impressions in middle. Scutellum ( Fig. 2D View FIGURE 2 ), triangular or semicircular. Metanotum ( Fig. 2F View FIGURE 2 ; mtn) strongly shortened.

Elytra fused, oval to fusiform, convex above; humeri straight, neither angulate nor swelled; disc with nine grooved or furrowed striae ( atavus - and metallicu s-group); or with striae interrupted, adjacent segments of striae oppositely curved, connected, forming rows of encircled areas ( aenescens - and elegantulu s-group); or with irregularly scattered strial punctures (most species of jendeki -group), or with irregularly distributed tubercles ( chongli - and jendeki -group); right elytron overlapping the left one at apex; epipleura oblique inwards, gradually narrowing apically. Hind wings absent.

Prosternum laterally fused with hypomera, pronotosternal sutures fine, prosternal process ( Fig. 2A View FIGURE 2 ; psp) dilated in ventral view, produced posteriorly, more or less declivous terminally. Mesoventrite with anterior ridges weakly and obtusely angulate anteriorly, anterior part with distinct shiny carina, sparsely pubescent. Metaventrite narrow, finely depressed along the midline, forming a suture; anterior metaventral process ( Fig. 2E View FIGURE 2 ; amtp) strongly protruded anteriorly, feebly convex and depressed at base, forming a wide V-shaped suture.

Abdomen more or less depressed in male, flattened or weekly convex in female. Intercoxal process of sternite III broad, quadrate, anterior margin weakly convex, wrinkled along anterior margin; sternites IV–VI convex in middle, and depressed in each side; sternites VI and VII usually sulcate along both sides, sternite VII with a pair of shallow impressions in middle; in some species, male sternites III and IV depressed in posterior middle, whose central part weakly convex; membranes visible between last three sternites. Defensive reservoirs elongate, transverse rings indistinct ( Fig. 2I View FIGURE 2 ).

Legs with femora and tibiae long and slender. Procoxae ( Fig. 2C View FIGURE 2 ) projecting below prosternum. Trochanters glabrous, without long setae. Profemora ventrally possessing one or two small impressions near each base; inner margins of tibiae pubescent along apical portions, in male pubescence denser and longer, forming ‘hair brush’, outer margin of pro- and mesotibiae often depressed near apices. Male pro- and mesotibiae more curved than those in female. Male pro- and mesotarsi slightly widened, all tarsomeres slanted.

Aedeagus, strongly sclerotized, curved in lateral view, parameres constricted before dilated apex, apex ovate to flabellate. Median lobe ( Fig. 2 View FIGURE 2 J–K; ml), strongly sclerotized, hamular, erected when mating. Sternite VIII strongly sclerotized and emarginated in male, with a pair of knife shaped or hooked apical lobes ( Fig. 17 View FIGURE 17 Ld, Ll; al) projecting at both sides of the apical notch.

Female genitalia with internal female reproductive tract consisting of slender vagina, opening into enlarged bursa copulatix ( Fig. 2O View FIGURE 2 , bc), oviduct ( Fig. 2O View FIGURE 2 , od) produced from vagina before bursa, slender spermathecal accessory gland ( Fig. 2O View FIGURE 2 , sag) attached at apex of bursa. Ovipositor ( Fig. 2O View FIGURE 2 , ov) strongly sclerotized, blade-like, coxites fused, curved strongly dorsad, gonostyles strongly reduced, extremely short. Spiculum ventrale ( Fig. 2N View FIGURE 2 ) with short trunk, weakly sclerotized.

Sexual dimorphism. Male: body slender, less markedly constricted between pronotum and elytra, less convex dorsally; abdomen depressed, sometimes with impressions on posterior middle of sternites III and IV; legs more elongate, tibiae more curved, modified in some species, with protrusions on inner margins of pro- and mesotibiae; pro- and mesotarsi more widened. Female: body wider or stouter, more markedly constricted between pronotum and elytra, more convex dorsally; abdomen flat, without impressions on posterior middle of sternites III and IV, legs less elongate in most species, tibiae less curved, without modifications; pro- and mesotarsi less widened.

Distribution ( Map 1 View Map 1 ). China, Myanmar, Thailand, Vietnam.

Comments. Inclusion of Morphostenophanes in the tribe Cnodalonini is supported by the structure of defensive reservoirs and presence of stellate sensoriae on antennomeres VII–XI. According to Bouchard & Yeates (2001, as Coelometopini), ovipositors are especially useful in determining close relationship within Cnodalonini . In the Oriental fauna, Ainu Lewis, 1894 (ovipositor shown in Yuan et al. 2018, Fig. 4L, M View FIGURE 4 ), Lycidioides Ando, 2003 (ovipositor shown in Masumoto & Akita 2007, Fig. 12 View FIGURE 12 ), Pseudonautes Fairmaire, 1893 , Scotaeus Hope, 1836 and Thesilea Haag-Rutenberg, 1878 ( Masumoto, 1981) have similar strongly sclerotized, blade like ovipositors. However, these genera are all winged and with general appearances being very different from Morphostenophanes . The Palaearctic apterous genus Stenophanes Solsky, 1876 shares the similar elongate habitus and unclavate femora with Morphostenophanes , however, it has weakly sclerotized ovipositor with segmented coxites (according to the observation of Stenophanes mesostena Solsky, 1871 specimens in CZDY). In fact, Hegemona Laporte, 1840 and Saziches Champion, 1886 both from Central America seems really closest related to Morphostenophanes , they share similar appearance, fused elytra, absent hindwings, similar internal female reproductive tracts and sclerotized ovipositor with fused gonocoxites (Doyen 1987), but they distinctly differ from Morphostenophanes in having non overlapping elytral apex, and different attachment point of spermathecal accessory gland. However, as the cnodalonine fauna is far from being clearly understood, it is too early to clarify the actual relationship between Morphostenophanes and other members within this tribe.

Morphostenophanes can be readily distinguished from other Oriental cnodalonine genera by the following characters: body medium-sized to large, elongate, gourd-shaped; clypeolabral membrane invisible; antennae slen- der, apical segments unclubbed, with antennomeres III–XI each elongate; pronotum with complete lateral marginal borders, without an indentation at each side before base; elytra fused, with right elytron overlapping the left one at apex. Hind wings absent. Procoxae each well projecting below prosternum. Femora not clavate. Male pro- and mesotarsi slightly widened. Parameres fused, slender, with dilated apex. Sternite VIII strongly sclerotized, with a pair of apical lobes projecting at both sides of the apical notch. Spermathecal accessory gland attached at apex of bursa. Ovipositor with gonocoxites fused, modified as a stout, sclerotized, laterally compressed, blade-like structure.

After cleaning several fresh specimens of Morphostenophanes linglong Zhou , new species and M. furvus Zhou , new species in warm water, a coagulated secretion was found at the apex of antennomere XI ( Fig. 1B View FIGURE 1 ). In a female specimen of Stenophanes mesostena the author also found the similar phenomenon. The antennal apices of these specimens were also observed under a 15x magnification, but no glands could be seen. The author speculates that the secretion could be some kind of pheromone related to mating. Electron microscopy is needed for a further study of their antennal surface, observation of more living individuals are needed to answer the function of the secretion, and further detailed study of all cnodalonine genera is needed to answer whether this phenomenon is common within the tribe.

In the present work, six species groups of the genus Morphostenophanes are proposed according to different morphological characters and geographical distribution.