Discoxenus latiabdominalis, 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 : 206-207

Discoxenus latiabdominalis n. sp.

( Figs. 1, 2 , 19–37 )

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: 2♂♂, 3♀♀, same data as holotype (1♂, completely dissected). 1♂, 3♀♀, 1 km S of Ankor Wat, Charles De Gaulle, Siem Reap, 22 VIII 2012, Maruyama M. leg. (Colony no. MMCB-T-2012-2-0022) (1♂, completely dissected, 1♀, abdominal segments VIII–X dissected off). 1♂, 2 km SE of Neak Pean, Siem Reap, 18 VIII 2014, Kakizoe S. & Maruyama M. leg. (Colony no. SK001).

Diagnosis. This species is distinguished from all other species by the macrochaetotaxy of abdominal tergites III–VIII (6, 6, 6, 6, 6, 4). This species is most similar to D. cambodiensis , but is easily distinguishable from it by a wider body ( Figs. 1, 2 ), hairy abdominal sternites III–IV, paramere with wider paramerite which is more than 5 times wider than condylite ( Fig. 36 ), and spermatheca with short basal part which is as long as apical part ( Fig. 37 ).

Description. Head ( Fig. 19 ) wider than long, with anterior margin of clypeus rounded. Antenna ( Figs. 1, 2 , 20 ) with segment II as long as segment IV, with 3 macrosetae; segment III trapezoidal, shorter than other segments; segment IV wider than long, dilated distally; segment V wider than other segments, slightly wider than long; segments VI–X successively narrowed distally; segment VI subquadrate; segments VII–X longer than wide; segment XI longer than other segments, widest at middle. Labrum ( Fig. 21 , left side) with anterior margin slightly concave; median projection of apodeme triangular, moderately pointed; 5 lateral setae present in ventral view ( Fig. 21 , right side). Mandibles ( Figs. 22, 23 ) covered with approximately 70 pores. Left mandible ( Fig. 22 ) with adoral margin moderately convex at middle. Right mandible ( Fig. 23 ) with a small and rounded tooth. Maxillary ( Fig. 24 ) palpal segment III approximately 2.2 times longer than wide. Mentum ( Fig. 25 ) short, approximately three times wider than long, covered with more than 60 pores. Labium ( Fig. 26 ) with prementum covered with approximately 40 pores.

Pronotum ( Fig. 27 ) sparsely covered with approximately 90 macrosetae. Elytron ( Fig. 28 ) transverse, sparsely covered with yellow setae, 21–23 macrosetae present on disc. Metaventrite ( Fig. 29 ) 1.3 times longer than mesoventrite.

Tergites ( Fig. 1 ) covered with pores, few setae present on lateral area and posterior margin except for tergites VI–VIII covered with much fewer setae. Tergite VIII ( Fig. 30 ) with posterior margin moderately pointed, 2 pairs of macrosetae present at posterior margin. Macrochaetotaxy of abdominal tergites III–VIII = 6, 6, 6, 6, 6, 4. Sternites ( Fig. 2 ) sparsely covered with setae, denser on sternites III and IV. Sternites III–VIII densely covered with minute pores anteriorly. Sternites III–VII with 6–12 macrosetae at posterior margin; sternites IV–VI with a row of 4–10 macrosetae at middle.

Male. Sternite VIII ( Fig. 31 ) with 5 pairs of macrosetae on posterior half. Median lobe of aedeagus ( Figs. 34, 35 ) with basal capsule longer than apical lobe. Paramere ( Fig. 36 ) with paramerite broad, more than 5 times wider than condylite; velar sac sclerite with 3 setae; apical lobe with 5–6 minute setae.

Female. Sternite VIII ( Fig. 32 ) with 5 pairs of macrosetae, several minute setae present at posterior margin. Spermatheca ( Fig. 37 ) with apical part 2 times wider than and as long as basal part.

Measurement. Body length = average 2.70 mm (2.56–2.84 mm, N = 7), pronotal length = average 0.65 mm (0.63–0.68 mm, N = 7), pronotal width = average 1.09 mm (1.04–1.17 mm, N = 7), elytral length = average 0.53 mm (0.49–0.56 mm, N = 7), elytral width = average 0.64 mm (0.63–0.71 mm, N = 7).

Etymology. The specific epithet is a combination of the Latin adjective latus meaning “broad” and the Latin adjective abdominalis, in reference to the diagnostic wide abdomen of the species.

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 19 – 37. Discoxenus latiabdominalis n. sp.: 19. Head, 20. Antenna, 21. Labrum (left side = dorsal view, right side = ventral view), 22. Mandible, left, 23. Mandible, right, 24. Maxilla, 25. Mentum, 26. Labium, 27. Pronotum, 28. Elytron, right, 29. Meso- and metaventrites, 30. Tergite VIII, 31. Sternite VIII, male, 32. Sternite VIII, female, 33. Tergites IX and X, 34. Median lobe of aedeagus, ventral view, 35. Median lobe of aedeagus, lateral view, 36. Paramere, 37. Spermatheca (ap: apical part, bp: basal part).