Malagasmus Gimmel, 2013

Gimmel, Matthew L., 2013, <strong> Genus-level revision of the family Phalacridae (Coleoptera: Cucujoidea) </ strong>, Zootaxa 3605 (1), pp. 1-147 : 87-88

22. Malagasmus Gimmel , gen. nov.

( Figs. 25 ; 41c, d )

Type species: Malagasmus thalesi Gimmel , here designated.

Type material. See account of Malagasmus thalesi below.

Diagnosis. Sharing many characters with Augasmus , including the oblique metatibial apical ctenidium and extremely long metatarsomere I, but readily distinguished by characters of the meso-metaventral region, including the truncate metaventral process not exceeding the mesocoxae anteriorly, and mesoventral plate not extending posteriorly and forming procoxal rests.

Description. Medium-sized to large, total length 2.7–3.7 mm. Dorsal color solid reddish-testaceous ( Figs. 41c, d ). Tibial spur formula 2-2-2, tarsal formula 5-5-4, presumably in both sexes (males unknown).

Head. Not constricted behind eyes. Eyes large; facets flat; interfacetal setae absent; deeply emarginate medially; without posterior emargination; periocular groove present; 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 weakly turbinate ( Fig. 25b ). Mandible ( Fig. 25a ) with apex simple; retinaculum absent; mandible without ventral ridge. Maxillary palpomere IV fusiform, elongate, nearly symmetrical; galea short, rounded; lacinia with two stout spines. Mentum parallel-sided; labial palpomere III triangular, expanded apically. Labrum with apical margin arcuate. Gular sutures short, barely evident .

Thorax. Pronotum without obvious microsetae; with distinct scutellar lobe. Prosternum anteriorly with row of marginal setae distributed evenly, setae normal; procoxal cavity without anterolateral notchlike extension; prosternal process angulate in lateral view, not distinctly setose preapically, without spinelike setae at apex. Protrochanter without setae; protibia with ctenidium on kickface extending about three-quarters length of tibia ( Fig. 25c ); apex of tibia with eversible pad (not usually visible in dry-mounted specimens). Scutellar shield small, width at base shorter than length of eye. Elytron with spectral iridescence; with one sutural stria; with transverse strigae; lateral margin with row of tiny, sawtooth-like setae. Mesoventral plate ( Fig. 25f ) notched anteriorly, not extending posteriorly to metaventrite, forming procoxal rests, mesoventral disc sunken medially, with scattered setae; mesanepisternum with complete transverse carina; mesocoxal cavities separated by less than half width of single coxal cavity. Mesotarsomere III not bilobed. Metaventral process ( Fig. 25f ) extending to about level of anterior margin of mesocoxae, truncate apically; metaventral postcoxal lines separated from mesocoxal cavity margin, following cavity borders; discrimen short, extending less than halfway to anterior margin of metaventral process; metendosternite ( Fig. 25g ) 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 markedly oblique, oriented about 45° to long axis of tibia; spurs cylindrical, longest spur longer than width of tibial apex; metatarsus as long as metatibia, metatarsomere I much longer than metatarsomere II, longer than remainder of tarsus, joint between I and II rigid ( Fig. 25d ); metatarsomere III not bilobed. Hind wing ( Fig. 25e ) with distinct, ovate anal lobe; leading edge without row of long setae; AA 3+4 faint, crossvein to Cu absent but two veins nearly anastomosing; cubitoanal system forked; CuA 2 and MP 3+4 with distal remnants; r4 barely indicated, incomplete; complex of flecks present in apical field distal to rp-mp2; long transverse sclerite and large nebulous 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 unknown. Female ovipositor weakly sclerotized, palpiform.

Immature stages. Unknown.

Bionomics. The type series of M. thalesi was collected in a Malaise trap.

Distribution and diversity. Known only from one species, occurring in Toliara Province, Madagascar ( Fig. 44a ).

Included species (1):

Malagasmus thalesi Gimmel , sp. nov. (Distribution: Madagascar)

Discussion. The protarsus of this genus was illustrated ( Fig. 25c ) with a membranous vesicle protruding from the first tarsomere, readily visible in the disarticulation but difficult to observe in dry-mounted specimens. It is unknown whether this morphological feature, which may function as an adhesive organ, is more widespread in Phalacridae . This issue deserves further investigation.

Etymology. From malago - (Malagasy) and - gasmus, in allusion to its similarity to the genus Augasmus . The gender of the name is masculine.

Figures

FIGURE 25. Malagasmus thalesi, 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 = 1.0 mm). (g) Metendosternite (scale bar = 0.5 mm). (h) Spermatheca (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.

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.