Platyphalacrus Gimmel, 2013

Gimmel, Matthew L., 2013, <strong> Genus-level revision of the family Phalacridae (Coleoptera: Cucujoidea) </ strong>, Zootaxa 3605 (1), pp. 1-147 : 64-65

15. Platyphalacrus Gimmel , gen. nov.

( Figs. 18 ; 39g –i )

Type species: Platyphalacrus lawrencei , here designated.

Type material. See account of Platyphalacrus lawrencei below.

Diagnosis. This genus is characterized by having a medially setose prosternum, metaventral process not produced and lobed anteriad of mesocoxae, metaventral postcoxal lines not separated from coxal cavities, metatarsomere I shorter than II, mandible tridentate, without ventral ridge and with strong retinaculum, and the flattened body form when viewed laterally.

Description. Medium-sized, total length 2.7–2.9 mm. Dorsal color completely reddish-testaceous ( Figs. 39g –i ). Tibial spur formula 2-2-2, tarsal formula 5-5- 5 in both sexes.

Head. Not constricted behind eyes. Eyes small; facets flat; interfacetal setae present; not emarginate medially; without posterior emargination; periocular groove present; with transverse setose groove ventrally behind eye. Frontoclypeus emarginate above antennal insertion; clypeal apex arcuate-truncate. Antennae short, antennal club 3- segmented, club symmetrical, weakly developed, antennomere XI constricted on anterior edge only ( Fig. 18b ). Mandible ( Fig. 18a ) with apex tridentate, with dorsal tooth smallest; with distinct retinaculum; mandible without ventral ridge. Maxillary palpomere IV fusiform, short, slender, nearly symmetrical; galea short, rounded; lacinia with two stout spines. Mentum with sides divergent toward apex; labial palpomere III fusiform. Labrum with apical margin slightly emarginate. Gular sutures short, barely evident .

Thorax. Pronotum without obvious microsetae; with quite 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, not conspicuously setose preapically, without spinelike setae at apex. Protrochanter with setae; protibia without ctenidium on kickface ( Fig. 18c ). Scutellar shield small. Elytron without spectral iridescence; with one sutural stria; disc of elytron with conspicuous rows of punctures; without transverse strigae; lateral margin somewhat explanate, especially posteriorly, with row of tiny, sawtooth-like setae. Mesoventral plate ( Fig. 18f ) notched anteriorly, not extending posteriorly to metaventrite, latero-posterior border obscured medially, forming procoxal rests; mesoventral disc depressed medially, not setose; mesanepisternum with complete transverse carina; mesocoxal cavities widely separate, separated by more than half width of a coxal cavity. Mesotarsomere III bilobed. Metaventral process ( Fig. 18f ) extending nearly to anterior level of mesocoxae, truncate anteriorly; metaventral postcoxal lines not separated from mesocoxal cavity margin; discrimen long, extending about halfway to anterior margin of metaventral process; metendosternite with anterior tendons moderately separated, ventral process intersecting ventral longitudinal flange at anterior margin. Anterior margin of metacoxa with emargination sublaterally; metacoxal plate with transverse line; metatibial foreface with apical ctenidium roughly perpendicular overall to long axis of tibia; spurs cylindrical, longest spur shorter than width of tibial apex; metatarsomere I shorter than metatarsomere II, joint between I and II rigid ( Fig. 18d ); metatarsomere III bilobed. Hind wing ( Fig. 18e ) with distinct, ovate anal lobe; leading edge with complete row of long setae at level of RA +ScP; AA 3+4 present, faint, crossvein to Cu absent; cubitoanal system unbranched apically, fused with faint remnant of CuA 2; CuA 2 and MP 3 with separate and faint distal remnants; r4 developed and connected with RA 3+4; strong flecks present in apical field just distal to rp-mp2, with fainter flecks more distally; long transverse proximal sclerite and additional large, faint triangular sclerite present just distal to end of radial bar.

Abdomen. Abdominal ventrite I without paired lines, with calli; spiracles present and apparently functional on segment VII. Male with aedeagus upright in repose; tegmen ( Fig. 18g ) with symmetrical anterior margin and parameres hinged to basal piece, parameres without medial longitudinal division; penis ( Fig. 18h ) with pairs of endophallic sclerites and spicules, apex truncate. Female ovipositor weakly sclerotized, palpiform.

Immature stages. Unknown.

Bionomics. Associated with male cones of Macrozamia cycads growing naturally in southwestern Australia. The beetles probably feed on the cycad pollen.

Distribution and diversity. Only one species so far known, restricted to the southwestern portion of Western Australia ( Fig. 44e ).

Included species (1):

Platyphalacrus lawrencei Gimmel , sp. nov. (Distribution: Australia)

Etymology. This genus is a combination of the Greek platys (flat) and the genus name Phalacrus , in reference to the flattened form of the type species, indeed the flattest known phalacrid. The gender of the name is masculine.

Figures

FIGURE 18. Platyphalacrus lawrencei, male. (a) Left mandible, dorsal; (b) left antenna (scale bar = 0.5 mm). (c) Left protibia and tarsus, dorsal; (d) right metatibia and tarsus, ventral (scale bar = 0.5 mm). (e) Hind wing (scale bar = 1.0 mm). (f) Meso- and metaventrite, ventral (scale bar = 1.0 mm). (g) Tegmen, ventral; (h) penis, ventral (scale bar = 0.5 mm).

FIGURE 39. Photographs. Megistopalpus simoni, lectotype: (a) dorsal; (b) view of antenna and maxillary palp. Phalacropsis dispar: (c) dorsal. Phalacrus rufoguttatus: (d) dorsal; (e) ventral. Austroporus sp.: (f) dorsal. Platyphalacrus lawrencei: (g) dorsal; (h) lateral; (f) ventral.

FIGURE 44. Collection localities. (a) Malagasmus thalesi distribution in Madagascar; (b) Malagophytus steineri distribution in Madagascar; (c) Antennogasmus cordatus distribution in southern Africa and Madagascar; (d) Paracylomus asiaticus distribution in Sri Lanka; (e) Platyphalacrus lawrencei distribution in Western Australia.