Entomocnemus Guillebeau, 1894

Gimmel, Matthew L., 2013, <strong> Genus-level revision of the family Phalacridae (Coleoptera: Cucujoidea) </ strong>, Zootaxa 3605 (1), pp. 1-147 : 104-107

28. Entomocnemus Guillebeau, 1894

( Figs. 31 ; 41i )

Entomocnemus Guillebeau 1894 a: 307 , as subgenus of Eustilbus Sharp. Type species: Eustilbus (Entomocnemus) raffrayi Guillebeau 1894 , fixed by monotypy. [elevated to generic rank by Švec 2003: 125]

Stilbomimus Champion 1924 c: 242 . Type species: Stilbomimus polymorphus Champion 1924 , fixed by original designation. Syn. nov.

Type material. Eustilbus raffrayi Guillebeau : holotype, card mounted, “Abyss. Raffray // Grouvelle // Museum Paris \ Coll. \ Générale // HOLOTYPE // Raffrayi Guilb.” ( MNHN).

Stilbomimus polymorphus Champion : seven syntypes found in BMNH, card-mounted specimen labeled “Type” by George Champion selected as a lectotype to stabilize the species name, “ Ceylon \ G. E. Bryant. // Kandy. VI.1908 [handwritten] // G. Bryant Coll. \ 1919–147 [on underside of label] // Type \ H. T. [red-bordered disc] // Stilbomimus polymorphus type Ch. [handwritten] // Stilbomimus polymorphus, Champ. // E.M.M. 1924 \ det. G.C.C. [on underside of label] // LECTOTYPE \ Stilbomimus \ polymorphus Champion \ des. M.L. Gimmel 2011 [red label]” ( BMNH). Paralectotypes (6, BMNH), from type locality in Sri Lanka and Nilgiri Hills, India, each with label affixed “ PARALECTOTYPE \ Stilbomimus \ polymorphus Champion \ det. M.L. Gimmel 2011 [yellow label]”. Champion’s “varieties” were excluded from the syntype series.

Diagnosis. A difficult genus to recognize, but possessing the following diagnostic characteristics: mesometaventral margin usually emarginate (but sometimes truncate) for reception of prosternal process (which may have apical translucent process), elytra with spectral iridescence, metaventral postcoxal lines not separated from coxal cavities, metatarsomeres I and II about equal, scutellar shield small, elytral striae (when present) more or less parallel to suture.

Description. Small to large, total length 1.6–3.5 mm. Dorsal color ranging from solid testaceous to solid black, some darker forms with red or yellow elytral maculations of various shapes and extent ( Fig. 41i ). Tibial spur formula 2-2-2 or 2-1-2, tarsal formula 5-5- 5 in both sexes.

Head. Not constricted behind eyes. Eyes small to medium-sized; facets flat; interfacetal setae absent; weakly emarginate medially; without posterior emargination; periocular groove present or absent; with transverse setose groove ventrally behind eye. Frontoclypeus emarginate above antennal insertion; clypeal apex arcuate-truncate. Antennal club 3-segmented, club weakly asymmetrical; antennomere XI not constricted ( Fig. 31b ). Mandible ( Fig. 31a ) with apex bidentate; retinaculum absent; mandible without ventral ridge. Maxillary palpomere IV short, fusiform, inner edge slightly swollen medially; galea short, rounded; lacinia with multiple spines. Mentum with sides divergent toward apex; labial palpomere III fusiform. Labrum with apical margin arcuate. Gular sutures short, barely evident .

Thorax. Pronotum without obvious microsetae; with weakly developed scutellar lobe. Prosternum anteriorly with continuous row of marginal setae, setae normal; procoxal cavity with anterolateral notchlike extension; prosternal process rounded to angulate in lateral view, not conspicuously setose preapically, without spinelike setae at apex, often with horizontal translucent process at apex. Protrochanter with setae; protibia usually without ctenidium on kickface ( Fig. 31c ), sometimes with short ctenidium extending about 1/5 length of tibia. Scutellar shield small. Elytron with spectral iridescence; with one or (occasionally) multiple striae, striae punctate; without transverse strigae; lateral margin with row of tiny, sawtooth-like setae. Mesoventral plate ( Fig. 31e ) deeply notched anteriorly, extending posteriorly to metaventrite, dividing mesoventral disc in two, forming procoxal rests; mesanepisternum with complete transverse carina; mesocoxal cavities moderately separate, separated by less than half width of a coxal cavity. Mesotarsomere III not bilobed. Metaventral process ( Fig. 31e ) extending beyond halfway point of mesocoxae, mesoventral lip on anterior edge usually emarginate, sometimes truncate; metaventral postcoxal lines not at all separated from mesocoxal cavity margin; discrimen short, extending less than halfway to anterior margin of metaventral process; metendosternite ( Fig. 31f ) with anterior tendons moderately separated, ventral process intersecting ventral longitudinal flange behind anterior margin. Anterior margin of metacoxa with emargination sublaterally; metacoxal plate without transverse line; metatibial foreface with apical ctenidium roughly perpendicular overall to long axis of tibia; spurs cylindrical, longest spur subequal to or longer than width of tibial apex; metatarsomere I about equal to metatarsomere II, joint between I and II flexible ( Fig. 31d ). Hind wing with distinct, ovate anal lobe; leading edge with complete row of long setae at level of RA +ScP; AA 3+4 absent; cubitoanal system unbranched apically; CuA 2 and MP 3+4 without distal remnants; r4 absent; flecks present in apical field distal to rp-mp2; long transverse proximal sclerite and strong irregular sclerite present just distal to end of radial bar.

Abdomen. Abdominal ventrite I without paired lines or calli; spiracles present and apparently functional on segment VII. Male with aedeagus upright in repose; tegmen with symmetrical anterior margin and parameres hinged to basal piece, parameres with medial longitudinal division; penis with with paired sclerites and fields of endophallic spicules, sometimes with long flagellum, apex trilobed; spiculum gastrale V-shaped, arms free. Female ovipositor weakly sclerotized, palpiform.

Immature stages. Unknown.

Bionomics. A series from Borneo was taken by beating the foliage of a downed Cinnamomum (Lauraceae) tree. Most other specimens from both southeast Asia and southern Africa with collection data have been taken by beating. A few have also been collected from Malaise traps.

Distribution and diversity. This genus occurs in two disjunct areas: subsaharan Africa and the Oriental region. There appear to be many undescribed species in southern Africa, but the actual number of species in southeast Asia, whose colorful species seem to be highly variable in appearance, is unknown at present.

Included species (8):

Entomocnemus borneensis (Champion, 1924) , comb. nov. ( Stilbomimus ) (Distribution: Malaysia) (type!) Entomocnemus diluticollis (Champion, 1924) , comb. nov. ( Stilbomimus ) (Distribution: India) (type!) Entomocnemus nyasanus (Champion, 1925) (Distribution: Malawi) (type!)

Entomocnemus polymorphus (Champion, 1924) , comb. nov. ( Stilbomimus ) ( Distribution : India, Indonesia, Sri Lanka) (type!)

Entomocnemus raffrayi (Guillebeau, 1894) (Distribution: Ethiopia) (type!)

Entomocnemus rhodesianus (Champion, 1925) (Distribution: Malawi, Zambia) (type!)

Entomocnemus triguttatus (Champion, 1925) , comb. nov. ( Heterolitus ) (Distribution: South Africa) (type!) Entomocnemus v-flavum (Champion, 1924) (Distribution: India) (type!)

Discussion. One of the most composite genera of those treated in this monograph, Entomocnemus as presently defined will likely require fracturing upon further study. The description given above is expanded to include a number of apparently undescribed species from both southern Africa and southeast Asia. Species I have examined tend to be represented by very few individuals, and this situation has made in-depth examination especially problematic. However, I believe Švec (2003) was correct in transferring the African species described in Stilbomimus to Entomocnemus . After examining types of all described species in question, I have concluded that the southeast Asian species (including the type species of Stilbomimus ) are also congeneric. The species placed in Entomocnemus (and Stilbomimus prior to this study) form a relatively well-defined group with slender tibiae and no protibial ctenidium, but are variable with regard to the development of the mesoventral emargination.

Figures

FIGURE 31. Entomocnemus sp., female. (a) Left mandible, dorsal; (b) left antenna (scale bar = 0.5 mm). (c) Right protibia and tarsus, dorsal; (d) left metatibia and tarsus, ventral (scale bar = 0.5 mm). (e) Meso- and metaventrite, ventral; (f) metendosternite (scale bar = 0.5 mm).

FIGURE 41. Photographs. Olibrus sp.: (a) dorsal. Antennogasmus cordatus, holotype: (b) dorsal. Malagasmus thalesi, holotype: (c) dorsal; (d) ventral. Olibrosoma testacea: (e) dorsal. Apallodes sp.: (f) dorsal. Augasmus humilis: (g) dorsal; (h) ventral. Entomocnemus sp., southeast Asia: (i) dorsal.