Discoxenus cambodiensis, Kanao, Taisuke & Maruyama, Munetoshi, 2015

Kanao, Taisuke & Maruyama, Munetoshi, 2015, Eight new species, a new record, and redescription of the genus Discoxenus Wasmann, 1904: The first record of termitophilous rove beetles in Cambodia (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 4044 (2), pp. 201-223 : 208-209

Discoxenus cambodiensis n. sp.

( Figs. 3, 4 , 38–53 )

Type materials. Holotype: ♂, 1 km S of Angkor Wat, Siem Reap, Cambodia, 18 VIII 2012, Maruyama M. leg. (Colony no. MMCB-T-2012-2-001).

Paratypes: Cambodia: 11♂♂, 5♀♀, same data as holotype (1♂, 1♀, completely dissected). 11♂♂, 13♀♀, 1 km SW of Angkor Wat, Siem Reap, 20 VIII 2012, Maruyama M. leg. (Colony no. MMCB-T-2012-2-0011). 1♀, 1 km W of Banteay Prei, Siem Reap, 21 VIII 2012, Maruyama M. leg. (Colony no. MMCB-T-2012-2-0019). 1♂, 1♀, same date and locality data as the former specimens (Colony no. MMCB-T-2012-2-0020). 3♂♂, 7♀♀, 1 km S of Ankor Wat, Charles De Gaulle, Siem Reap, Maruyama M. leg. (Colony no. MMCB-T-2012-2-0022). 2♂♂, 8♀♀, 1.6 km SW of Angkor Wat, Siem Reap, 21 VIII 2014, Kakizoe S. leg. (Colony no. SK010).

Diagnosis. This species is easily distinguished from all other species by the macrochaetotaxy of tergites III– VIII (6, 6, 6, 4, 4, 4). This species is most similar to D. latiabdominalis , but is distinguishable from it by a more slender body ( Figs. 3, 4 ), abdominal sternites V–VII without setae except for posterior margin, paramere with narrower paramerite which is approximately 4 times wider than condylite ( Fig. 52 ), and spermatheca with longer basal part which is approximately 2 times longer than apical part ( Fig. 53 ).

Description. Head ( Fig. 38 ) approximately 1.5 times wider than long, with anterior margin of clypeus rounded. Antenna ( Figs. 3, 4 , 39 ) with segment I longer than other segments; segment II as long as segment IV, with 3 macrosetae; segment III bowl shaped, shorter than other segments; segment IV wider than long, dilated distally; segment V wider than other segments, wider than long; segments VI–X successively narrowed distally; segments VI–VII wider than long; segment VIII subquadrate; segments IX–X longer than wide; segment XI approximately 2.3 times longer than wide, widest at middle. Labrum ( Fig. 40 , left side) with anterior margin concave; median projection of apodeme rounded; 5–6 lateral setae present in ventral view ( Fig. 40 , right side). Mandibles ( Figs. 41, 42 ) covered with more than 80 pores. Left mandible ( Fig. 41 ) moderately produced adorally at middle. Right mandible ( Fig. 42 ) with a small and rounded tooth. Maxillary palpal segment III approximately 2.3 times longer than wide. Mentum ( Fig. 43 ) 2 times wider than long, covered with more than 70 pores. Labium with prementum covered with 15–20 pores.

Pronotum ( Fig. 44 ) sparsely covered with more than 80 macrosetae. Elytron ( Fig. 45 ) transverse, sparsely covered with yellow setae, 21–23 macrosetae present on disc. Metaventrite 1.3 times longer than mesoventrite, without macrosetae.

Tergites III–VIII ( Fig. 3 ) glabrous, almost without setae except for each posterior margin. Tergite VIII ( Fig. 46 ) with posterior margin moderately rounded, 2 pairs of macrosetae present at posterior margin, with 4 short setae at middle of posterior margin. Macrochaetotaxy of abdominal tergites III–VIII = 6, 6, 6, 4, 4, 4. Sternites III–IV ( Fig. 4 ) partially covered with setae. Sternites V–VIII almost nude. Sternites III–VIII densely covered with minute pores anteriorly. Sternites III–VI with a row of 4–8 macrosetae at posterior margin.

Male. Sternite VIII ( Fig. 47 ) with 4 pairs of macrosetae on posterior half, minute setae present at posterior margin. Median lobe of aedeagus ( Figs. 50, 51 ) with basal capsule longer than apical lobe. Paramere ( Fig. 52 ) with paramerite approximately 4 times wider than condylite; velar sac sclerite with 3 setae; apical lobe with 3 minute setae at apex.

Female. Sternite VIII ( Fig. 48 ) with 3 pairs of macrosetae, several minute setae present at posterior margin. Spermatheca ( Fig. 53 ) with basal part more than 2 times longer than apical part.

Measurement. Body length = average 1.91 mm (2.11– 1.75 mm, N = 10), pronotal length = average 0.66 mm (0.65–0.68 mm, N = 10), pronotal width = average 0.96 mm (0.92–1.00 mm, N = 10), elytral length = average 0.46 mm (0.43–0.51 mm, N = 10), elytral width = average 0.63 mm (0.61–0.66 mm, N = 10).

Etymology. The specific Latinized epithet is derived from Cambodia where its type locality was found.

Host species. Odontotermes maesodensis Ahmad, 1965 .

Figures

FIGURES 1 – 4. Habitus. 1 – 2. Discoxenus latiabdominalis n. sp.: 1. Dorsal view, 2. Ventral view. 3 – 4. D. cambodiensis n. sp.: 3. Dorsal view, 4. Ventral view.

FIGURES 38 – 53. Discoxenus cambodiensis n. sp.: 38. Head, 39. Antenna, 40. Labrum (left side = dorsal view, right side = ventral view), 41. Mandible, left, 42. Mandible, right, 43. Mentum, 44. Pronotum, 45. Elytron, right, 46. Tergite VIII, 47. Sternite VIII, male, 48. Sternite VIII, female, 49. Tergites IX and X, 50. Median lobe of aedeagus, ventral view, 51. Median lobe of aedeagus, lateral view, 52. Paramere, 53. Spermatheca.