Grouvelleus Guillebeau, 1892

Gimmel, Matthew L., 2013, <strong> Genus-level revision of the family Phalacridae (Coleoptera: Cucujoidea) </ strong>, Zootaxa 3605 (1), pp. 1-147 : 111-112

30. Grouvelleus Guillebeau, 1892

( Figs. 2g ; 33 ; 42a, b )

Grouvelleus Guillebeau 1892 c : cxxxiv. Type species: Grouvelleus prosternalis Guillebeau 1892 , fixed by monotypy.

Ochrolitoides Champion 1924 c: 245 . Type species: Ochrolitoides magister Champion 1924 , fixed by original designation. Syn. nov.

Litotarsus Champion 1925 b: 615 . Type species: Litotarsus dilutus Champion 1925 , fixed by original designation. Syn. nov.

Type material. Grouvelleus prosternalis Guillebeau : holotype, female, “ Saigon [handwritten] // Type // Grouvelleus \ prosternalis \ Guilb. [handwritten] // type ex \ Guillebeau \ Ann. Fr. 1893.378 [handwritten] \ Collection FLEUTIAUX // HOLOTYPE ♀ \ Grouvelleus \ prosternalis Guillebeau \ det. M.L. Gimmel 2009 [red label]” ( MNHN), point mounted.

Ochrolitoides magister Champion : lectotype, here designated, male, “[male symbol] // Kandy , \ Ceylon // G.E. Bryant \ VI.1908 [handwritten] // G. Bryant Coll. \ 1919–147 // Ochrolitoides \ magister, \ Champ. // E.M.M. 1924. \ det. G.C.C. // See slide Coll. \ No. ESL 55 // Ochrolitoides \ magister \ type Ch [handwritten] // SYN- \ TYPE [blue-bordered disc] // LECTOTYPE ♂ \ Ochrolitoides \ magister Champion \ des. M.L. Gimmel 2010 [red label]” ( BMNH), point mounted, genitalia removed from specimen and slide mounted by E.S. Lewis. Paralectotype: same data as lectotype, female, with label affixed “ PARALECTOTYPE ♀ \ Ochrolitoides \ magister Champion \ det. M.L. Gimmel 2010 [yellow label]” ( BMNH).

Litotarsus dilutus Champion : holotype, male, “Type \ H. T. // Specimen figured. // See slide Coll. \ No. ESL 89 // G. Bryant Coll. \ 1919–147 // Quop, \ W. Sarawak. \ III-IV.1914. \ G.E. Bryant. // prost. process \ forming rec. \ in mesost. // Gen. NOT \ Grouvelleus , \ 1892 Guill // Litotarsus \ dilutus, \ type Ch. // Ann. Mag. N.H. \ Ser 9. xvi.1925. \ G.C.C. det. // HOLOTYPE \ Litotarsus \ dilutus Champion \ det. M.L. Gimmel 2010 [red label]” ( BMNH), point mounted, genitalia removed from specimen and slide mounted by E.S. Lewis.

Diagnosis. This genus has a number of bizarre features that readily separate it from the rest of the Phalacridae . The mesocoxae are nearly contiguous, and the meso-metaventral junction lies behind the midpoint of the coxae. From a ventral aspect the prosternal process appears as a spearpoint-shaped posterior projection, and the procoxal rests on the mesoventral plate are large. The maxillary galea is elongate and acuminate, and the terminal maxillary palpomere is long and knife-shaped. Additionally, the distinctly punctate elytral striae are among the most prominent in the family.

Description. Small to very large, total length 1.8–4.5 mm. Dorsal color solid reddish-testaceous ( Figs. 42a, b ) to solid black, some darker forms with bicolored elytra. Tibial spur formula 2-2-2, 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 loosely 3-segmented, club weakly asymmetrical; antennomere XI not or weakly constricted ( Fig. 33b ). Mandible ( Fig. 33a ) with apex bidentate; retinaculum absent; mandible without ventral ridge. Maxillary palpomere IV long, flattened and knife-shaped, inner edge swollen; galea elongate, tapered; lacinia with multiple stout spines. Mentum with sides divergent toward apex; labial palpomere III slightly expanded, triangular, labial palpomere II often with cluster of large stout setae ( Fig. 2g ), palpomere III with one or two stout setae on outer margin before apex. Labrum with apical margin slightly emarginate. Gular sutures short, barely evident.

Thorax. Pronotum without obvious microsetae; with weakly developed scutellar lobe. Prosternum anteriorly with continuous row of marginal setae, setae flattened at base; procoxal cavity with anterolateral notchlike extension; prosternal process angulate in lateral view, long and spearpoint-shaped in ventral view, usually conspicuously setose preapically, without spinelike setae at apex. Protrochanter without setae; protibia with ctenidium on kickface extending almost entire length of tibia, often extending around apex to level of apical spurs ( Fig. 33c ). Scutellar shield small, width at base subequal to length of eye. Elytron with spectral iridescence; with nine distinct, more-or-less complete striae, medialmost striae not convergent apically; without transverse strigae; lateral margin without row of sawtooth-like setae. Mesoventral plate ( Fig. 33f ) notched anteriorly, not extending posteriorly to metaventrite, forming deep procoxal rests; mesoventral disc depressed medially; mesanepisternum with complete transverse carina; mesocoxal cavities nearly contiguous, barely separated by a strip of cuticle. Mesotarsomere III not bilobed. Metaventrite short ( Fig. 33f ); metaventral process not quite reaching halfway point of mesocoxae; metaventral postcoxal lines not separated from mesocoxal cavity margin, or separated only slightly but following cavity borders; discrimen short, not quite extending halfway to anterior margin of metaventral process; metendosternite ( Fig. 33g ) 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; metatibia sometimes greatly expanded ( G. tibialis ); metatibial foreface with apical ctenidium straight, roughly perpendicular overall to long axis of tibia; spurs cylindrical, longest spur shorter than or subequal to width of tibial apex; metatarsomere I much shorter than metatarsomere II, to subequal to metatarsomere II, joint between I and II rigid ( Fig. 33d ); metatarsomere III not bilobed. Hind wing ( Fig. 33e ) with distinct, ovate anal lobe; leading edge with incomplete row of long setae; AA 3+4 present, connected by crossvein to Cu; cubitoanal system branched apically; CuA 2 and MP 3+4 with distal remnants; r4 complete, connecting RP with RA 3+4; large 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 ( Fig. 33h ) with symmetrical anterior margin and parameres hinged to basal piece, parameres without medial longitudinal division; penis ( Fig. 33i ) narrow, with fields of endophallic spicules and sclerites, apex with two truncate processes; spiculum gastrale with arms vshaped, connected by broad lamina or not. Female ovipositor weakly sclerotized, palpiform.

Immature stages. Unknown.

Bionomics. Gut contents reveal unidentified fungal material. Information on labels is quite meager, but a long series of G. dilutus was collected by beating foliage.

Distribution and diversity. Members of this genus occur in the humid tropical belt of the Afrotropical Region (new record for this realm) from Sierra Leone to Uganda, south to Angola. I have seen no specimens from Madagascar. In the Oriental realm they occur from India and Sri Lanka to Vietnam to Borneo. The African fauna is entirely undescribed, and there are new species from southeast Asia.

Included species (7):

Grouvelleus anisotomoides (Champion, 1925) , comb. nov. ( Litotarsus ) (Distribution: Myanmar) (type!) Grouvelleus dilutus (Champion, 1925) , comb. nov. ( Litotarsus ) (Distribution: Malaysia) (type!)

Grouvelleus magister (Champion, 1924) , comb. nov. ( Ochrolitoides ) (Distribution: Sri Lanka) (type!) Grouvelleus magnus (Motschulsky, 1866) , comb. nov. ( Litotarsus ) (Distribution: Sri Lanka)

Grouvelleus prosternalis Guillebeau, 1892 ( Distribution : Vietnam) (type!)

Grouvelleus siamensis (Champion, 1924) , comb. nov. ( Ochrolitoides ) (Distribution: Thailand) (type!) Grouvelleus tibialis ( Švec, 2006) , comb. nov. ( Litotarsus ) (Distribution: Malaysia)

Discussion. The previously described species of Grouvelleus , Litotarsus , and Ochrolitoides share a number of important characters (mentioned in the diagnosis), and I have synonymized them here. Their type species differ principally in body size and length ratios of metatarsomeres I and II, but there are other species in this group that exhibit intermediate character states. The tarsal configuration was the primary criterion Champion (1925 b) used in justifying his new genus Litotarsus , so I believe his comment written on a label attached to the holotype of L. dilutus (see above) carries no weight.

Figures

FIGURE 2. Key characters for Phalacridae. (a) Schematic of dorsal characters showing small scutellar shield and two sutural striae. (b) Schematic of dorsal characters showing large scutellar shield and one sutural stria. Frontal view of head capsule of (c) Stilbus; (d) Phalacrus; (e) Tolyphus. (f) Maxillary palpus of Megistopalpus. Labial palpus of (g) Grouvelleus; (h) Phalacrinus (scale bar = 0.5 mm); (i) Phaenocephalus (scale bar = 0.2 mm). Dorsal view of head capsule of (j) Phaenocephalus; (k) Phalacrinus; (l) Acylomus (scale bars = 0.5 mm). Ventral view of head capsule of (m) Xanthocomus; (n) Nesiotus.

FIGURE 33. Grouvelleus dilutus, male. (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). (h) Tegmen, ventral; (i) penis, ventral (scale bar = 0.5 mm).

FIGURE 42. Photographs. Grouvelleus n.sp., Africa: (a) dorsal; (b) ventral. Litochropus n.sp.: (c) dorsal; (d) ventral. Litochrus sp.: (e) dorsal; (f) ventral. Malagophytus steineri, holotype: (g) dorsal. Neolitochrus pulchellus: (h) dorsal; (i) ventral.