Discoxenus katayamai Kanao & Maruyama, 2010

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 : 220

Discoxenus katayamai Kanao & Maruyama, 2010

( Figs. 17, 18 , 149–164 )

Discoxenus katayamai Kanao & Maruyama, 2010: 79 .

Additional materials. Cambodia: 8 sex?, 500 m S of Ankor Wat, Siem Reap, 5 VI 2012, Maruyama M. (Colony no. MMCB-T-2012-1-001). 2♀♀, 1 km S of Angkor Wat, Siem Reap, 18 VIII 2012, Maruyama M. leg. (Colony no. MMCB-T-2012-2-002). 3♂♂, 2♀♀, North Wall of Preah Khan, Siem Reap, 19 VIII 2012, Maruyama M. leg. (Colony no. MMCB-T-2012-2-006) (1♂, completely dissected, 1♀, abdominal segments dissected off). 2♂♂, 6♀♀, Bayon, Ankor Thom, Siem Reap, 20 VIII 2012, Maruyama M. leg. (Colony no. MMCB-T-2012-2-008) (1♂, 1♀, abdominal segments dissected off). 1♀, 1 km W of Banteay Prei, Siem Reap, 21 VIII 2012, Maruyama M. leg. (Colony no. MMCB-T-2012-2-0016). 1♂, 9♀♀, 1 km S of Ankor Wat, Charles De Gaulle, Siem Reap, 22 VIII 2012, Maruyama M. leg. (Colony no. MMCB-T-2012-2-0023) (1♀, completely dissected). 3♂♂, 1♀, 2 km SE of Neak Pean, Siem Reap, 18 VIII 2014, Kakizoe S. & Maruyama M. leg. (Colony no. SK001). 2♂♂, 2♀♀, 0.76 km NE of Preah Kham, Siem Reap, 18 VIII 2014, Kakizoe S. & Maruyama M. leg. (Colony no. SK003). 1♀, 0.65 km N of Preah Kham, Siem Reap, 19 VIII 2014, Kakizoe S. leg. (Colony no. SK004). 3♀♀, 0.76 km NE of Preah Kham, Siem Reap, 19 VIII 2014, Kakizoe S. leg. (Colony no. SK008). 7♂♂, 17♀♀, 0.77 km E of Angkor Wat, Siem Reap, 24 VIII 2014, Kakizoe S. & Maruyama M. leg. (Colony no. SK015). 2♂♂, 2♀♀, same locality data to SK002, 25 VIII 2014, Kakizoe S. leg. (Colony no. SK019). 1♀, 1.8 km W of Neak Pean, Siem Reap, 26 VIII 2014, Kakizoe S. leg. (Colony no. S022).

Diagnosis. This species is distinct, and is easily distinguishable from other Discoxenus species by a combination of the following character states: antennal segment XI thick and approximately 1.4 times longer than wide ( Fig. 150 ), elytra and abdominal tergites sparsely covered with yellow setae ( Fig. 17 ).

Redescription. Head ( Fig. 149 ) approximately 1.6 times wider than long. Antenna ( Figs. 17, 18 , 150 ) with segment I longer than other segments; segment II as long as segment III, with 3 macrosetae; segment III bowl shaped; segment IV transverse; segments V–VII wider than other segments; segments VIII–X gradually narrowed distally; segment VIII slightly wider than long; segments IX–X subquadrate; segment XI approximately 1.4 times longer than wide, widest around middle. Labrum ( Fig. 151 , left side) with anterior margin slightly concave at middle; median projection of apodeme short, with apex rounded; 4–5 lateral setae present in ventral view ( Fig. 151 , right side). Mandibles ( Figs. 152, 153 ) covered with 15–20 pores. Left mandible ( Fig. 152 ) with adoral margin moderately pointed around middle. Right mandible ( Fig. 153 ) with a distinct tooth. Maxillary palpal segment III approximately 2 times longer than wide. Mentum ( Fig. 154 ) approximately 2.8 times wider than long, covered with around 40 pores. Labium with prementum covered with approximately 6 pores.

Pronotum ( Fig. 155 ) covered with approximately 48 macrosetae. Elytron ( Fig. 156 ) transverse, sparsely covered with yellow setae, 14 macrosetae present on disc. Metaventrite approximately 1.6 times longer than mesoventrite.

Tergites ( Fig. 17 ) and sternites ( Fig. 18 ) sparsely covered with yellow setae. Tergite VIII ( Fig. 157 ) with posterior margin rounded, 3 pairs of macrosetae present at posterior margin, with 2 pairs of macrosetae around middle. Macrochaetotaxy of abdominal tergites III–VIII = 6, 6, 6, 6, 6, 6. Sternites III–VII ( Fig. 18 ) with 4–8 macrosetae at posterior margin.

Male. Sternite VIII ( Fig. 158 ) with posterior margin slightly rounded, 3 pairs of macrosetae present at posterior margin, with 2 pairs of macrosetae at middle. Median lobe of aedeagus narrowed apically in ventral view ( Fig. 161 ); basal capsule with distal crest large in lateral view ( Fig. 134 ); apical lobe less than half as wide as basal capsule in lateral view ( Fig. 162 ). Paramere ( Fig. 163 ) with paramerite approximately 3 times wider than condylite; velar sac sclerite with 7–8 setae; apical lobe with 2 minute setae at apex.

Female. Sternite VIII ( Fig. 159 ) with 2 pairs of macrosetae at posterior margin and middle, respectively. Spermatheca ( Fig. 164 ) with basal part more than 3 times longer than apical part.

Measurement. Body length = average 1.52 mm (1.46–1.58 mm, N = 10), pronotal length = average 0.52 mm (0.49–0.56 mm, N = 10), pronotal width = average 0.74 mm (0.71–0.78 mm, N = 10), elytral length = average 0.38 mm (0.36–0.41 mm, N = 10), elytral width = average 0.41 mm (0.39–0.44 mm, N = 10).

Host species. Odontotermes proformosanus Ahmad, 1965 .

Comments. This species was originally described from Thailand ( Kanao & Maruyama 2010). The close morphological comparisons revealed that there are only a few morphological differences between the Thai and the Cambodian specimens: the elytra of the Cambodian specimens are slightly wider than that of the Thai specimens; the Cambodian specimens have a slightly broader distal crest of the median lobe. We, therefore, consider these populations as conspecific. In this paper, we have redescribed this species to include additional morphological details.

Figures

FIGURES 13 – 18. Habitus. 13 – 14. Discoxenus lucidus n. sp.: 13. Dorsal view, 14. Ventral view. 15 – 16. D. kakizoei n. sp.: 15. Dorsal view, 16. Ventral view. 17 – 18. D. katayamai: 17. Dorsal view, 18. Ventral view.

FIGURES 149 – 164. Discoxenus katayamai: 149. Head, 150. Antenna, 151. Labrum (left side = dorsal view, right side = ventral view), 152. Mandible, left, 153. Mandible, right, 154. Mentum, 155. Pronotum, 156. Elytron, right, 157. Tergite VIII, 158. Sternite VIII, male, 159. Sternite VIII, female, 160. Tergites IX and X, 161. Median lobe of aedeagus, ventral view, 162. Median lobe of aedeagus, lateral view, 163. Paramere, 164. Spermatheca.

FIGURES 121 – 136. Discoxenus lucidus n. sp.: 121. Head, 122. Antenna, 123. Labrum (left side = dorsal view, right side = ventral view), 124. Mandible, left, 125. Mandible, right, 126. Mentum, 127. Pronotum, 128. Elytron, right, 129. Tergite VIII, 130. Sternite VIII, male, 131. Sternite VIII, female, 132. Tergites IX and X, 133. Median lobe of aedeagus, ventral view, 134. Median lobe of aedeagus, lateral view, 135. Paramere, 136. Spermatheca.