Pseudolibrus Flach, 1889

Gimmel, Matthew L., 2013, <strong> Genus-level revision of the family Phalacridae (Coleoptera: Cucujoidea) </ strong>, Zootaxa 3605 (1), pp. 1-147 : 48-51

10. Pseudolibrus Flach, 1889

( Figs. 13 ; 38f )

Pseudolibrus Flach 1889 a: 270 . Type species: Pseudolibrus gestroi Flach 1889 , fixed by monotypy.

Biophytus Guillebeau 1894 a: 279 . Type species: Biophytus grouvellei Guillebeau 1894 , fixed by original designation. Syn. nov. Polyaloxus Guillebeau 1894 a: 283 . Type species: Lithocrus pallidus Wollaston 1867 , fixed by original designation. Syn. nov.

Type material. Pseudolibrus gestroi Flach : holotype, “Bogos 1870 \ Sciotel [handwritten] \ O. Beccari. // Museo Civ. \ Genova // Olibrus \ pallescens \ m. [handwritten] // Olibrus \ pallescens \ n.sp. in litt. [handwritten] \ det. E.Reitter //? TYPUS of \ Pseudolibrus \ gestroi Flach, 1889 \ R.Poggi [handwritten] [red label] // HOLOTYPE \ Pseudolibrus \ gestroi Flach \ det. M.L. Gimmel 2011 [red label]” ( MSNG), card mounted.

Biophytus grouvellei Guillebeau : holotype, “Grouvelle [handwritten] // Zanzibar \ Raffray [green label] // HOLOTYPE [red label] // [illegible] // Museum Paris \ Coll. \ Générale // Grouvellei \ Guilb. // HOLOTYPE \ Biophytus \ grouvellei Guillebeau \ det. M.L. Gimmel 2009 [red label]” ( MNHN), card mounted.

Lithocrus pallidus Wollaston : lectotype, here designated, “ Type [orange-bordered disc] // pallidus, Woll. [handwritten] // CAPE VERDE IS. \ S. Iago \ T. V. Wollaston Coll. \ B.M. 1867–82. // SYN- \ TYPE [blue-bordered disc] // Lithocrus \ pallidus W. [handwritten] // LECTOTYPE \ Lithocrus \ pallidus Wollaston \ des. M.L. Gimmel 2010 [red label]” ( BMNH), card mounted. Three paralectotypes, with same data, with labels affixed “ PARALECTOTYPE \ Lithocrus \ pallidus Wollaston \ det. M.L. Gimmel 2010 [yellow label]” ( BMNH). The lectotype is here designated to stabilize the identity of the species and of the generic name Polyaloxus Guillebeau.

Diagnosis. Easily recognized by the combination of nine nearly complete elytral striae, large scutellar shield, and unmodified maxillary palps. Additional characters aiding in identification are lack of frontoclypeal emargination above antennal insertion, the presence of a protibial ctenidium, and metatarsomere I longer than II.

Description. Small to medium-sized, total length 1.5–2.7 mm. Color solid testaceous to solid black, darker specimens often with lighter elytral apices ( Fig. 38f ). Tibial spur formula 2-2-2, tarsal formula 5-5- 5 in both sexes.

Head. Not constricted behind eyes. Eyes medium-sized; facets convex; interfacetal setae absent; weakly emarginate medially; without posterior emargination; periocular groove absent; with transverse setose groove ventrally behind eye. Frontoclypeus not emarginate above antennal insertion; clypeal apex arcuate-truncate. Antennal club loosely 3-segmented, club weakly asymmetrical; antennomere XI weakly turbinate ( Fig. 13b ). Mandible ( Fig. 13a ) slender, with apex tridentate; with weak retinaculum; mandible without ventral ridge. Maxillary palpomere IV fusiform, nearly symmetrical; galea rounded; lacinia with two stout spines. Mentum with sides divergent toward apex; labial palpomere III elongate, fusiform. Labrum with apical margin arcuate. Gular sutures short, barely evident .

Thorax. Pronotum with distinct, scattered microsetae; without scutellar lobe. Prosternum anteriorly with continuous row of marginal setae, setae normal; procoxal cavity with anterolateral notchlike extension; prosternal process angulate in lateral view, usually conspicuously setose preapically, without spinelike setae at apex. Protrochanter without setae; protibia with ctenidium on kickface extending about one-third to one-half length of tibia ( Fig. 13c ). Scutellar shield large, about as long as or longer than length of eye. Elytron without spectral iridescence; with nine distinct, more-or-less complete striae, medialmost stria somewhat convergent apically, second stria (first discal) fusing with sutural stria before apex; with distinct transverse strigae, strongest laterally; lateral margin with row of tiny, sawtooth-like setae. Mesoventral plate ( Fig. 13f ) notched anteriorly, not extending posteriorly to metaventrite, forming procoxal rests; mesoventral disc depressed medially, setose; mesanepisternum with complete transverse carina; mesocoxae approximate, separated by less than half width of a coxal cavity. Mesotarsomere III not bilobed. Metaventral process ( Fig. 13f ) extending anteriorly just to halfway point of mesocoxae; metaventral postcoxal lines not separated from mesocoxal cavity margin; discrimen short, not quite extending halfway to anterior margin of metaventral process; metendosternite ( Fig. 13g ) with anterior tendons moderately separated, ventral process intersecting ventral longitudinal flange behind anterior margin. Anterior margin of metacoxa with emargination sublaterally; metacoxal plate with transverse line; metatibial foreface with apical ctenidium straight, perpendicular overall to long axis of tibia; spurs cylindrical, longest spur subequal to width of tibial apex; metatarsomere I longer than metatarsomere II, but shorter than remainder of tarsus, joint between I and II rigid ( Fig. 13d ). Hind wing ( Fig. 13e ) with distinct, ovate anal lobe; leading edge without long setae; AA 3+4 not apparent; cubitoanal system not forked; CuA 2 and MP 3+4 without distal remnants; r4 absent; curved fleck present in apical field distal to rp-mp2; small transverse sclerite and medium-sized nebulous 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 without medial longitudinal division; penis parallel-sided, elongate, with small field of endophallic spicules, apex simple; spiculum gastrale with arms parallel, connected by broad lamina. Female ovipositor weakly sclerotized, palpiform.

Immature stages. Unknown.

Bionomics. Collection methods on labels are meager, but many were collected at lights and others were collected in Malaise traps. The gut of one dissected specimen contained large numbers of tripartite fungal spores.

Distribution and diversity. Exclusively Afrotropical, extending from Cape Verde and Liberia to Eritrea, Tanzania, Madagascar, Seychelles, and South Africa. A few undescribed species exist.

Included species (5):

Pseudolibrus gestroi Flach, 1889 ( Distribution : Eritrea) (type!)

Pseudolibrus grouvellei (Guillebeau, 1894) , comb. nov. ( Biophytus ) (Distribution: Tanzania) (type!) Pseudolibrus pallidus (Wollaston, 1867) , comb. nov. ( Polyaloxus ) (Distribution: Cape Verde) (type!) Pseudolibrus snizeki ( Švec, 2006) , comb. nov. ( Biophytus ) (Distribution: Uganda)

Pseudolibrus striatus (Champion, 1925) , comb. nov. ( Polyaloxus ) ( Distribution : Angola, South Africa) (type!)

Discussion. The respective type species of Pseudolibrus Flach , Biophytus Guillebeau , and Polyaloxus Guillebeau are nearly identical, and the other included species in the latter two genera fit well within the generic concept described above. Unfortunately, the oldest genus-group name in this group of genera is Pseudolibrus , which had not been used since its original publication. Biophytus has been used as valid in the past 50 years, but apparently not by 10 or more authors in 25 works, so a reversal of precedence cannot occur without petition to the ICZN (see ICZN 1999, Article 23.9). This will have unpleasant consequences for any family-group name that may eventually apply to this group, since the two available are based on a synonymized (in the case of Biophytini Guillebeau) or on younger (in the case of Megapalpini Guillebeau) generic names.

Figures

FIGURE 13. Pseudolibrus sp., female. (a) Left mandible, dorsal; (b) left antenna (scale bar = 0.5 mm). (c) Left protibia and tarsus, dorsal; (d) left metatibia and tarsus, ventral (scale bar = 0.5 mm). (e) Hind wing (scale bar = 1.0 mm). (f) Meso- and metaventrite, ventral (scale bar = 0.5 mm). (g) Metendosternite (scale bar = 0.5 mm).

FIGURE 38. Photographs. Nesiotus n.sp.: (a) dorsal. Stilbus nr. apicalis, male: (b) dorsal; (c) ventral. Xanthocomus sp.: (d) dorsal; (e) ventral. Pseudolibrus sp.: (f) dorsal. Litostilbus testaceus: (g) dorsal; (h) ventral. Litostilbus sp., southeast Asia: (i) dorsal.