Phalacrinus Blackburn, 1891

Gimmel, Matthew L., 2013, <strong> Genus-level revision of the family Phalacridae (Coleoptera: Cucujoidea) </ strong>, Zootaxa 3605 (1), pp. 1-147 : 23-26

2. Phalacrinus Blackburn, 1891

( Figs. 2h, k ; 5 ; 37c )

Phalacrinus Blackburn 1891: 99 . Type species: Phalacrinus australis Blackburn 1891 , here designated.

Sphaerostilbus Champion 1924 b: 164 . Type species: Sphaerostilbus dilatatus Champion 1924 , fixed by original designation. Syn. nov.

Type material. Phalacrinus australis Blackburn : holotype, “ T \ 781 [handwritten] // Type \ H. T. [red-bordered disc] // Australia. [underlined with red] \ Blackburn Coll. \ B.M. 1910–236. // Phalacrinus \ australis, Blackb. // LECTOTYPE \ Phalacrinus \ australis Blackburn \ des. M.L. Gimmel 2012 [red label]” ( BMNH), card mounted.

Sphaerostilbus dilatatus Champion : lectotype, here desginated, “W. Almora Divn \ Kumaon U.P. \ Oct. 1917. HGC // E 25 [handwritten] // Type \ H. T. [red-bordered disc] // Sphaerostilbus \ dilatatus, Ch \ type [handwritten] // Specimen \ figured // Sphaerostilbus \ (n. gen.) \ dilatatus, Champ. // Ent. Mo. Mag. 1924. \ G. C. C. det. // G.C. Champion. \ Brit. Mus. \ 1924–63. // SYN- \ TYPE [blue-bordered disc] // LECTOTYPE \ Sphaerostilbus \ dilatatus Champion \ des. M.L. Gimmel 2011 [red label]” ( BMNH), card mounted. Paralectotypes from same locality (1), Nilgiri Hills, India (3), and Mt. Matang, Sarawak, Borneo (2), each with label “ PARALECTOTYPE \ Sphaerostilbus \ dilatatus Champion \ det. M.L. Gimmel 2011 [yellow label]” ( BMNH).

Diagnosis. Perhaps the most distinctive genus of Phalacridae . The explanate pronotal and elytral margins, antennomere I flattened and triangular, terminal labial palpomere widest apically, elevated mesoventral disc, and constriction of the head behind the eyes serve to easily separate Phalacrinus from the rest of the family.

Description. Medium-sized, total length 2.0–3.0 mm. Pronotal and elytral margins distinctly explanate. Dorsal surface from completely testaceous to nearly black, often with nebulously lighter sutural area and elytral margins ( Fig. 37c ). Tibial spur formula 0-1-1, tarsal formula 4-4- 4 in both sexes.

Head. Distinctly constricted behind eyes ( Fig. 2k ); with extremely short median endocarina at occiput. Eyes medium-sized; facets flat; interfacetal setae absent; not emarginate medially; without posterior emargination; periocular groove absent; with transverse setose groove ventrally behind eye. Frontoclypeus emarginate or not above antennal insertion; clypeal apex truncate. Antennomere I flattened, with antero-apical knob, appearing triangular; antennal club loosely 3-segmented, club symmetrical, nearly cylindrical, long, usually about as long as funicle; antennomere XI constricted on posterior face ( Fig. 5b ). Mandible ( Fig. 5a ) stout, with apex simple or sometimes bidentate, tip strongly bent medially and acuminate; without or with weak retinaculum; mandible without ventral ridge. Maxillary palpomere IV fusiform, relatively short, stout; galea securiform; lacinia with multiple spines. Mentum with sides divergent toward apex; labial palpomere III triangular, widest at apex ( Fig. 2h ). Labrum with apical margin slightly emarginate. Gular sutures long, strongly convergent, extending about halfway to ventral mouthparts.

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 in lateral view, not setose preapically, without spinelike setae at apex. Procoxae nearly contiguous; protrochanter with setae; protibia ( Fig. 5c ) without ctenidium on kickface, apical spurs absent. Scutellar shield small, width at base less than length of eye. Elytron without spectral iridescence; usually with nine more or less complete impressed striae, striae with distinct punctures; without transverse strigae; lateral margin without row of sawtooth-like setae. Mesoventral plate deeply notched anteriorly, not extending posteriorly to metaventrite, not forming procoxal rests; mesoventral disc elevated medially, forming a large plate anterior to metaventral process, setose; mesanepisternum with transverse carina present, incomplete; mesocoxae separated by less than half width of a coxal cavity ( Fig. 5f ). Mesotarsomere III not bilobed. Metaventral process ( Fig. 5f ) extending anteriorly just to halfway point of mesocoxae; metaventral postcoxal lines not separated from mesocoxal cavity margin; discrimen long, extending more than halfway to anterior margin of metaventral process; metendosternite ( Fig. 5g ) with anterior tendons moderately separated, ventral process intersecting ventral longitudinal flange at anterior margin. Anterior margin of metacoxa without emargination sublaterally; metacoxal plate without transverse line; metatibial foreface with apical ctenidium straight, perpendicular overall to long axis of tibia; apical spur cylindrical, distinctly shorter than width of tibial apex; metatarsomeres compacted, nearly identical to mesotarsomeres, joint between I and II flexible ( Fig. 5d ); metatarsomere III not bilobed. Hind wing ( Fig. 5e ) with distinct, ovate anal lobe; leading edge with complete row of long setae at level of RA +ScP; AA 3+4 not apparent; cubitoanal system not forked; CuA 2 and MP with distal remnants; r4 absent; apical field with curved fleck present distal to rp-mp2; small transverse sclerite and small round sclerite present just distal to end of radial bar.

3+4

Abdomen. Abdominal ventrite I without paired lines or calli; spiracles absent on segment VII. Male with aedeagus upright in repose; tegmen ( Fig. 5h ) with symmetrical anterior margin, parameres separated by suture from basal piece, parameres with medial longitudinal division; penis ( Fig. 5i ) wider posteriorly, with fields of endophallic spicules and sclerites, bilobed apically; spiculum gastrale V-shaped, arms free. Female ovipositor weakly sclerotized, palpiform.

Immature stages. Unknown.

Bionomics. Most specimens with capture data indicate that they were beaten from dry leaves, often of Eucalyptus . A few have been taken by litter sifting.

Distribution and diversity. Exclusively Indo-Australian, from India eastward to the Philippines and throughout Australia. Surprisingly, I have seen none from New Guinea.

Included species (10):

Phalacrinus australis Blackburn, 1891 ( Distribution : Australia) (type!)

Phalacrinus comis Blackburn, 1895 ( Distribution : Australia) (type!)

Phalacrinus compressus Blackburn, 1902 ( Distribution : Australia) (type!)

Phalacrinus dilatatus (Champion, 1924) , comb. nov. ( Sphaerostilbus ) (Distribution: India, Malaysia) (type!) Phalacrinus navicularis Blackburn, 1902 (Distribution: Australia) (type!)

Phalacrinus nigriclavus Lea, 1932 (Distribution: Australia)

Phalacrinus notabilis Blackburn, 1895 ( Distribution : Australia) (type!)

Phalacrinus obtusus Blackburn, 1891 ( Distribution : Australia) (type!)

Phalacrinus rotundus Blackburn, 1891 ( Distribution : Australia) (type!)

Phalacrinus umbratus Blackburn, 1902 ( Distribution : Australia) (type!)

Discussion. Champion’s genus Sphaerostilbus falls well within the concept of Phalacrinus outlined in the diagnosis above, and therefore I propose synonymy of the two here. Neither Blackburn nor subsequent authors have designated a type species for Phalacrinus . I have selected P. australis Blackburn to typify the genus name since it is the best described of the three available species treated in Blackburn’s (1891) publication.

Only one specimen was discovered from the type series of P. australis in the BMNH. Although Blackburn did not enumerate the specimens he had in making his description, he did mention two localities in this context ( Port Lincoln and Morgan, South Australia) necessitating two or more specimens. Damoiseau (1968: 29), in fact, indicated that an additional specimen from the syntype series was present in Institut Royal des Sciences Naturelles de Belgique, Brussels, Belgium ( IRSNB; not examined). I have therefore designated the BMNH specimen as the lectotype .

Champion’s type series of S. dilatatus consists of seven specimens from multiple localities in India and Borneo. I have designated one specimen the lectotype in order to stabilize the identity of the species .

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 5. Phalacrinus dilatatus, male. (a) Right 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) 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 37. Photographs. Phaenocephalus sp.: (a) dorsal; (b) ventral. Phalacrinus sp.: (c) dorsal. Ranomafanacrinus nigrinus, holotype: (d) dorsal; (e) lateral; (f) ventral. Acylomus aciculatus: (g) dorsal; (h) ventral. Acylomus bicolor: (i) dorsal.