Discoxenus phourini, 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 : 209-211

Discoxenus phourini n. sp.

( Figs. 5, 6 , 54–72 )

Type materials. Holotype: ♂, Koh Kong, Cambodia, 7 XII 2012, Kanao T. leg. (Colony no. KT428).

Paratypes: 4♂♂, 7♀♀, same data as holotype (1♂, completely dissected, 1♀, abdominal segments VIII–X dissected off).

Diagnosis. This species is easily distinguished from other Discoxenus species by a combination of the following two character states: macrochaetotaxy of tergite III–VIII (6, 6, 6, 6, 6, 6), and sternites IV–VII with two macrosetae at middle of each subapical area. This species is most similar to D. hirsutus , but is distinguishable from it by the elytra with 12–13 macrosetae on disc ( Fig. 63 ), and spermatheca with the longer basal part which is 2 times longer than basal part ( Fig. 72 ).

Description. Head ( Fig. 54 ) more than 1.5 times wider than long, with anterior margin of clypeus produced anteriorly. Antenna ( Figs. 5, 6 , 55 ) with segment I longer than other segments; segment II as long as segment III, with 2 macrosetae; segment III bowl shaped; segment IV transverse, wider than other segments; segments V–XI successively narrowed distally; segments V–VI wider than long; segment VI subquadrate; segments VII–X longer than wide; segment XI approximately 2.4 times longer than wide, narrowed apically. Labrum ( Fig. 56 , left side) with anterior margin deeply concave; median projection of apodeme rounded; 6–7 lateral setae present in ventral view ( Fig. 56 , right side). Mandibles ( Figs. 57, 58 ) covered with approximately 30 pores. Left mandible ( Fig. 57 ) with adoral margin moderately pointed around middle. Right mandible ( Fig. 58 ) with a tooth moderately pointed. Maxillary ( Fig. 59 ) palpal segment III approximately 2.3 times longer than wide. Mentum ( Fig. 60 ) approximately 2.4 times wider than long, covered with around 50 pores. Labium with prementum covered with 6–7 pores.

Pronotum ( Fig. 62 ) sparsely covered with approximately 50 macrosetae, several minute setae present around anterior margin. Elytron ( Fig. 63 ) transverse, sparsely covered with setae at anterolateral outer corner, 12–13 macrosetae present on disc. Metaventrite ( Fig. 64 ) 1.3 times longer than mesoventrite.

Tergites III–V ( Fig. 5 ) covered with few setae laterally. Tergites VI–VIII with 4–6 setae on posterior half. Tergite VIII ( Fig. 65 ) with posterior margin moderately pointed, 3 pairs of macrosetae present at posterior margin, 2 pairs of macrosetae present around middle. Macrochaetotaxy of abdominal tergites III–VIII = 6, 6, 6, 6, 6, 6. Sternite III ( Fig. 6 ) densely covered with setae. Sternites IV–VIII with posterior half covered with several setae. Sternites III–VII with a row of 6–10 macrosetae at posterior margin. Sternites IV–VII with a pair of macrosetae at middle of subapical area.

Male. Sternite VIII ( Fig. 66 ) with posterior half covered with few setae, 3 pairs of macrosetae at posterior margin and middle. Median lobe of aedeagus moderately narrowed to apical lobe in ventral view ( Fig. 69 ); basal capsule ventrally concave at middle in lateral view ( Fig. 70 ); apical lobe half as wide as basal capsule in lateral view ( Fig. 70 ); distal crest produced with rounded apex. Paramere ( Fig. 71 ) with paramerite more than 3 times wider than condylite; velar sac sclerite with 5 setae; apical lobe with 3 minute setae at apex.

Female. Sternite VIII ( Fig. 67 ) with 3 pairs of macrosetae at posterior margin and middle. Spermatheca ( Fig. 72 ) with basal part approximately 2 times longer than apical part.

Measurement. Body length = average 1.85 mm (1.76–1.93 mm, N = 10), pronotal length = average 0.59 mm (0.57–0.62 mm, N = 10), pronotal width = average 0.88 mm (0.83–0.90 mm, N = 10), elytral length = average 0.40 mm (0.38–0.43 mm, N = 10), elytral width = average 0.44 mm (0.42–0.46 mm, N = 10).

Etymology. This specific name is dedicated to Mr. Phourin Chhang of the Forestry Administration of Phnom Penh, Cambodia, for his hearty support during field surveys in Cambodia by TK.

Host species. Hypotermes makhamensis Ahmad, 1965 .

Figures

FIGURES 5 – 12. Habitus. 5 – 6. Discoxenus phourini n. sp.: 5. Dorsal view, 6. Ventral view. 7 – 8. D. kohkongensis n. sp.: 7. Dorsal view, 8. Ventral view. 9 – 10. D. hirsutus n. sp.: 9. Dorsal view, 10. Ventral view. 11 – 12. D. minutus n. sp.: 11. Dorsal view, 12. Ventral view.

FIGURES 54 – 72. Discoxenus phourini n. sp.: 54. Head, 55. Antenna, 56. Labrum (left side = dorsal view, right side = ventral view), 57. Mandible, left, 58. Mandible, right, 59. Maxilla, 60. Mentum, 61. Labium, 62. Pronotum, 63. Elytron, right, 64. Meso- and metaventrites, 65. Tergite VIII, 66. Sternite VIII, male, 67. Sternite VIII, female, 68. Tergites IX and X, 69. Median lobe of aedeagus, ventral view, 70. Median lobe of aedeagus, lateral view, 71. Paramere, 72. Spermatheca.