Gamepenthes ornatus (Lewis, 1894)

Arimoto, Koichi & Arimoto, Hisayuki, 2020, The genus Nipponodrasterius Kishii (Coleoptera, Elateridae, Agrypninae), a junior synonym of the genus Gamepenthes Fleutiaux (Coleoptera, Elateridae, Elaterinae), with review of the Japanese Gamepenthes species, ZooKeys 1004, pp. 109-127 : 109

Gamepenthes ornatus (Lewis, 1894) Figures 1A , 3A, B , 4A, B , 7A

Megapenthes ornatus Lewis, 1894: 47 (original description; type locality: Yuyama, Kumamoto Prefecture, Kyushu, Japan).

Gamepenthes ornatus (Lewis, 1894); Kishii 1959: 58 (changed generic status).

Megapenthes ornatus aberrant form basalis Nakane, 1958: 87 (original description; type locality: Mt. Osore-zan, Aomori Prefecture, Honshu, Japan).

Material examined.

2 females, Japan, Honshu, Nara Prefecture, Yoshino District, Kamikitayama Village, Amagase, 11 VII 2004, Hisayuki Arimoto leg. [females: GO001, GO002]; 1 male, Japan, Honshu, Nara Prefecture, Yoshino District, Totsukawa Village, Asahi, Mt. Syakaga-take, 1450 m, 4 VIII 2019, Hisayuki Arimoto leg., from flowers of Tilia japonica [male:GO003]; 3 males, 1 female, Japan, Honshu, Wakayama Prefecture, Tanabe City, Mt. Gomadan-zan, 18 VII 2019, Hisayuki Arimoto leg. [males: GO004-GO006; female: GO007]; 2 females, Japan, Honshu, Nara Prefecture, Tenkawa Village, near Gyôjagaeshi Tunnel, 900 m, 16 VII 2017, Hisayuki Arimoto leg. [GO008, GO009]; 1 male, Japan, Honshu, Wakayama Prefecture, Tanabe City, Mt. Jyôgamori-yama, 18 VII 2019, Hisayuki Arimoto leg. [GO010]; 1 female, Japan, Honshu, Okayama Prefecture, Tomada District, Kagamino Town, Neji, 8-15 VII 2016, Akihiko Watanabe leg., by light FIT [GO011]; 1 male, Japan, Kyushu, Kumamoto Prefecture, Uki City, Mt. Shiraiwa-yama, 16-17 VII 2016, Ryô Noda leg. [GO012]; 2 females, Japan, Kyushu, Miyazaki Prefecture, Nishiusuki District, Gokase Town, Mt. Shiraiwa-yama, 1347 m, 32°34'13.7"N, 131°06'51.6"E, 30 VII 2011, Kôichi Arimoto leg. [GO013, GO014].

Diagnosis.

Body robust (EI: 238-254, BI: 220-236). Prothorax black in male, brown in female. Each elytron with pale orange U-shaped marking basally. Antennomere II shorter than wide in male, almost as long as wide in female; III shorter than wide in male, longer than wide in female; IV robust (1.36-1.53 times longer than wide in male, 1.69-1.79 times longer than wide in female), longer than II-III combined (1.53-1.99 times as long as II-III combined in male, 1.02-1.10 times as long as in female). Prosternal process weakly inclined dorsad (24-38°). Metacoxal plates not narrowed outwards on lateral half; outer edge wide. Apical edge of elytra serrate. Apex of parameres beyond pre-apical expansions equilateral triangular (apex length 0.8-0.9 times width of parameres at expansion).

Measurements.

Male (6 spec.). BL: 5.29-6.18; BW: 1.41-1.72; MAE: 0.893-1.07; MBE: 0.599-0.719; OI: 148-154; PL: 1.47-1.82; PML: 1.24-1.51; PAW: 0.925-1.08; PW: 1.41-1.70; PI: 105-107; PWI: 150-156; EL: 3.47-4.12; EW: 1.41-1.72; EI: 238-246; BI: 226-236. Female (8 spec.). BL: 5.86-7.03; BW: 1.57-1.93; MAE: 0.929-1.12; MBE: 0.620-0.764; OI: 141-150; PL: 1.71-2.12; PML: 1.42-1.81; PAW: 0.956-1.14; PW: 1.57-1.93; PI: 106-111; PWI: 161-174; EL: 3.90-4.67; EW: 1.57-1.93; EI: 242-254; BI: 220-230.

Distribution.

Japan: Honshu, Shikoku, Kyushu.

Comparative notes.

Gamepenthes ornatus and G. versipellis (Lewis, 1894) are often found sympatrically and are remarkably similar. They are distinguished by apical expansion of parameres beyond apical-lateral hooks ( G. ornatus , apex length 0.8-0.9 times width of parameres at expansion; G. versipellis , 0.5-0.6 times width of parameres at expansion) (Fig. 7A, D ).

Ôhira (1995a) distinguished G. ornatus from G. versipellis in the key by the antennomere II ( G. ornatus , longer than wide; G. versipellis , shorter than wide) and color of the basal outer edge of the elytra ( G. ornatus , pale orange, Fig. 1A ; G. versipellis , black, Fig. 1D ). However, in both species, the males’ antennomere II is shorter than wide (Fig. 3A ), and in females, it is almost as long as or slightly longer than wide (Fig. 3B ). Moreover, their elytral base is variable in color, and we found specimens [GO001, GO016] of G. versipellis with a pale orange basal outer edge of the elytra. The two species are difficult to distinguish using antennomere II and elytral color. In females, pronotum coloration is a good diagnostic character ( G. ornatus , brown, Fig. 4B ; G. versipellis , red, Fig. 4D ) because no pronotum color variation has been found in either species. Considering the possibility that females with non-red pronota have been found, pronotum shape is the best diagnostic character for both sexes of the two species except for aedeagus ( G. ornatus , PWI 150-156 in male and 161-174 in female; G. versipellis , PWI 172-184 in male and 176-191 in female) (Fig. 4A-D ).

Figures

Figure 1. Gamepenthes spp., male, habitus, dorsal view A G. ornatus [GO 003] B G. pictipennis [GP 010] C G. similis [GS 003] D G. versipellis [GV 006] E G. yoshidai [GY 001].

Figure 3. Gamepenthes spp. A-F right basal antennomeres G, H left metacoxal plate I, J apices of elytra A G. ornatus, male [GO 003] B G. ornatus, female [GO 009] C G. pictipennis, male [GP 010] D G. pictipennis, female [GP 011] E G. similis, male [GS 003] F G. similis, female [GS 006] G, I G. versipellis [GV 011] H G. pictipennis [GP 010] J G. pictipennis [GP 003].

Figure 4. Gamepenthes spp., head and prothorax A G. ornatus, male [GO 003] B G. ornatus, female [GO 002] C G. versipellis, male [GV 006] D G. versipellis, female [GV 007] E G. pictipennis, male [GP 010] F G. yoshidai, male [GY 001] A-D dorsal view E, F lateral view.

Figure 7. Gamepenthes spp., male, aedeagus, ventral side A G. ornatus [GO 006] B G. pictipennis [GP 006] C G. similis [GS 008] D G. versipellis [GV 003] E G. yoshidai [GY 002].