Bolbochromus malayensis Li & Krikken

Li, Chun-Lin, Yang, Ping-Shih, Krikken, Jan & Wang, Chuan-Chan, 2013, Three new species of Bolbochromus Boucomont (Coleoptera, Geotrupidae, Bolboceratinae) from Southeast Asia, ZooKeys 290, pp. 39-54 : 48-50

Bolbochromus malayensis Li & Krikken sp. n. Figs 3 –49–1217–1821– 22

Holotype

male. The holotype is glued to a paper point and labeled: MALAYSIA: Selangor// Ulu Gombak// 21. V.-3. VI. 2003// Maruyama M. (FIT) (deposited at the National Museum of Nature and Science, Tokyo, Japan).

Paratype.

1 female, with the same collecting data as the holotype.

Type locality.

Western Malaysia: Selangor State, Ulu Gombak, 3°35'N, 101°78'E (Fig. 23).

Description.

Holotype male (Figs 3, 9, 11). Body length 6.8 mm; greatest width 3.8 mm. Form ovate, sides subparallel. Dorsum of head, pronotum, interval 1 (sutural interval), and base of elytron black with elytral striae and remaining intervals brownish black to yellowish brown; round, brownish yellow markings located on lateral third of pronotum, 2 additional minor marking at sides of basal one-third of midline (Fig. 11); elytral markings across base of striae 1-8 and interval 9, shape transversely irregular (Fig. 3). Head: Labrum with anterior margin feebly triangularly concave centrally, sides notched. Clypeal apex trapezoidal with lateral border rounded (Fig. 9), anterior margin beaded, surface rugosely punctate, confluent or separated by less than 1 puncture diameter. Clypeofrontal suture absent. Vertex with an inconspicuous convexity of carina at middle of base, coarse punctures on surface same as those on clypeus, moderately distributed. Thorax: Outline of pronotum transverse, surface coarsely punctate along side of disc, moderately dense; midline moderately indented with well-defined, coarse punctures; area in front of elytral base impunctate with coarse punctures at anterior one-third of sides of midline (Fig. 9); disc gradually declined anteriorly when viewed laterally (Fig. 11). Metasternal process poorly developed, narrowly separating middle coxae with anterior margin beaded. Scutellum slightly longer than wide medially, surface with 5 coarse punctures and scattered secondary punctures,. Elytron: With 7 striae between suture and humeral umbone, stria 2 interrupted by stria 1 not reaching base, stria 5 terminating at basal one-ninth; width of interval 3 and 4 same at basal one-fifth with interval 2, 5 and 6 less convex than others (Figs 3, 11). Legs: Protibia with 10 distinct teeth on outer margin, apical 3 teeth protruding, tip of apical tooth curved outwardly. Male genitalia: Length 1.7 mm. Parameres (Figs 17-18) elongate, dorsal margin slightly declined at basal one-fifth, becoming more declivous at apical one-fourth (Fig. 21), well sclerotized laterally with apical part membranous, surface almost impunctate, glabrous; subequal in length to basal piece. Median lobe (Figs 17-18) trilobate; dorsal sclerite vertically bilobed with apex notched; lateral sclerites elongate, equal in length to dorsal sclerite, overall highly sclerotized, apex tufted with 4 robust setae (Fig. 22); supporting sclerites kidney-shaped, evenly sclerotized. Internal sac embedded in median lobe. Temones membranous, thin and elongate to apex of basal piece (Fig. 17). Basal piece with apical portion asymmetrical.

Paratype female (Fig. 4, 10, 12). Similar to holotype male with minor differences of lighter body color, secondary punctures on pronotum and scutellum, smaller eyes, larger brownish yellow marking of elytra and robust protibial teeth.

Diagnosis.

Bolbochromus malayensis is similar to Bolbochromus masumotoi , but it can be distinguished based on the following combination of characteristics: smaller in body size ( Bolbochromus masumotoi with larger; body length>8.0 mm); clypeal apex trapezoidal (rounded in Bolbochromus masumotoi ); vertex with an inconspicuous carina at middle of base (a tubercle at center of frontal disc in Bolbochromus masumotoi ); pronotal marking rounded (triangular in Bolbochromus masumotoi ); punctures on pronotum coarse and moderately dense (fine and sparse in Bolbochromus masumotoi ); pronotum smoothly declined anteriorly (steeply declined in Bolbochromus masumotoi ); elytral striae coarsely punctate (finely punctate in Bolbochromus masumotoi ); elytral intervals varying in degree of convexity (evenly convex in Bolbochromus masumotoi ); elytral markings across interval 2-9, transversely irregular (markings across intervals 4-8, shape rounded in Bolbochromus masumotoi ); dorsal sclerite of median lobe widened (narrow in Bolbochromus masumotoi ).

Etymology.

Bolbochromus malayensis is the first species of the genus described from the Malay Peninsula, and the species epithet is derived from its locality.

Remarks.

The holotype and paratype of Bolbochromus malayensis were collected by a flight interception trap, which is an effective method for collecting Bolbochromus adults. A series of papers by Hanski and Krikken (1991), Davis (2000), Davis et al. (2001), and Li et al. (2008) demonstrated that flight interception traps are highly effective for collecting forest-dwelling bolboceratine scarabs.