Echinoaesalus timidus ( Krikken, 1975 )

Huang, Hao, Bartolozzi, Luca & Chen, Chang-Chin, 2015, Notes on the genus Echinoaesalus Zelenka, 1993 (Coleoptera: Lucanidae), with the description of a new species from the Malay Peninsula, Zootaxa 4039 (4), pp. 553-565 : 559-562

Echinoaesalus timidus ( Krikken, 1975)

( Figs. 3 , 16–18, 21–30, 33–34, 39–48 , 53–54, 64–67, 70–73 , 80–86, 93–98, 100, 107, 109–110)

Material. INDONESIA: 1 ♂ (L08), South Sumatra, Lampung province, Bukit Barisan Selatan National Park, 5 km SW Liwa, 5°4′S, 104°4′E, 600 m, 7–17.II.2000, J. Bezdek; 1 ♀ (L09), East Sumatra, Riau province, Bukit Tigapuluh N.P., 0°50′S, 102°26′E, 18-25.I.2000, J. Bezdek leg. INDONESIA: 1 ♂ (L02), BORNEO, South Kalimantan province, Kandangan district, Loksado 17 km NE, 900 m, 15.XI.1997 – 15.XI.1998; 1 ♀ (L06), MALAYSIA, Sabah, Mt. Trus Madi, 1200 m, III–IV.2005, local collector. MALAYSIA: 1 ♂ (L21), 1 ♀ (L13), Pahang, Benom Mts., 15 km E Kampong Dong, 3.53ºN, 102.01ºE, 700 m, 1.IV.1998, D. Hauck; 1 ♂ (L22), Pahang, Perak, 40 km SE of Ipoh, Banjaran Titi Wangsa, Ringlet, 900 m, 29.III–15.IV.2004, P. Cechovsky; 1 ♂ (L30), 1 ♀ (L20), Johor, 30 km N of Kota Tinggi, Kangkar Dohol, 35 m, 7–11.IV.2007, P. Cechovsky; 3 ♂♂ (L17, L19, & L23), 3 ♀♀ (L24, L25, & L29), Pahang, 70 km SW of Kuala Rompin, Endau Rompin National Park, G.Beremban (Kg. Tebu Hitam), 600 m, 13.IV–3.V.2009, P. Cechovsky; 1 ♂ (L18), 1 ♀ (L31), Pahang, 30 km SE of Ipoh, Banjaran Titi Wangsa, Tanah Rata, 1500 m, 14–15.III.2002, P. Cechovsky; 1 ♂ (L26), 1 ♀ (L32), Pahang, Cameron Highlands Mts., Tanah Rata, 1000–1500 m, 2–9.IV.1997, P. Cechovsky; 5 ♂♂, 3 ♀♀ (L33– L40), Kelantan, 60 km NE of Tanah Rala, Tanah Kerajaan, 1000 m, 12–30.IV.2007, P. Cechovsky.

Remarks. Species in the subgenus Zelenkaesalus Krikken, 2008 share most of the external characters and differ from one another only by very few external characters that are restricted to the third antennomere, mentum, protibia, and pronotal plate. After an examination of 15 males and 12 female of E. timidus , we found that the color of bristle clumps and the groove on mentum can be highly individually variable in a single species. The original description ( Krikken 1975) and the recent discussion ( Krikken 2008) of E. timidus reveal the characters of mentum, pronotal plate, and protibia in holotype of which the sex has not been examined ( Krikken 1975, 2008). The male specimens from Sumatra (the type locality) and Borneo examined by us are in common with the holotype of E. timidus in all these diagnostic characters. However, the male specimens from Malay Peninsula have the groove(s) of mentum varied from a pair of comma-shaped pits at lateral sides ( Fig. 16) to a single transversal sulcus ( Figs. 17–18), with some intermediate forms ( Figs. 24–25). All these male specimens have been dissected and proved to be the same species. However, all female specimens from Sumatra, Borneo, and the Malay Peninsula have only a single transversal sulcus on mentum. Therefore we suspect that the holotype of E. timidus should be a male. The sexual dimorphism of E. timidus is the same as that of the E. hidakai group, not presented in the outer apex of the protibia and the posterior margin of the last visible abdominal ventrite as in the E. matsuii group.

It should be noted that the holotype of E. timidus ( Fig. 124 ) has dorsal line of elytra in lateral view weakly produced at summit, not evenly convex as shown in the original description ( Krikken 1975: fig. 6). All the specimens of E. timidus examined by us are in common with the holotype for this character.

The following external characters of E. timidus have not been described before. Third antennomere ( Fig. 3 ) stouter than in E. sabahensis and E. gedeensis . Hindwing venation ( Figs. 53–54) as in E. arayai , E. chungi , and E. gedeensis , different from that of the E. hidakai group by having vein 3dA2 almost reaching margin of wing and vein 3dA1 nearly in parallel with vein 2dA3. Posterior margin of pronotal plate of male ( Figs. 64–67 ) gently curved or rounded. Pronotal plate of female ( Figs. 70–73 ) more elongate than in male, usually with more curved posterior margin. 9th abdominal segment of male (Figs. 80–86) shorter than in other species of the subgenus Zelenkaesalus, with a short basal lobe.

Male genitalia ( Figs. 93–98, 100 ). Nine male specimens from Sumatra, Borneo, and the Malay Peninsula have been dissected and show the same genital characters. The size of the aedeagus is constantly smaller and shorter than in other species of the subgenus Zelenkaesalus. Parameres nearly half as long as median lobe. Median lobe with lateral colorless splits, and with a terminal ventral plate clearly defined by the lateral splits, more or less enlarged at terminal end.

Female genitalia ( Figs. 107, 109–110 ). Accessory gland rooted on bursa copulatrix at lateral side near the terminal end of bursa copulatrix. Bursa copulatrix small and short, hardly separable from bursal duct in width. Bursal duct rather short and wide. Spermatheca and its duct rooted on bursa copulatrix at the opposite side to the duct of accessory gland near the terminal end of bursa copulatrix. Spermathecal duct short. Spermathecal gland and its duct very long.

Distribution. Sumatra (type locality), Borneo, the Malay Peninsula, and Thailand.

Figures

FIGURES 1 – 7. Antenna. 1, Echinoaesalus hidakai, L 12, western Malaysia; 2, E. borneoensis, L 11, Borneo; 3, E. timidus, L 19, western Malaysia; 4, E. sabahensis, L 14, Borneo; 5, E. gedeensis, holotype, Java; 6, E. cechovskyi, holotype, western Malaysia; 7, E. cechovskyi, paratype, Singapore. Arrow directed to end of third antennomere.

FIGURES 35 – 52. Protibia (left), mesotibia (middle), and metatibia (right), or just protibia. 35, Echinoaesalus hidakai, L 12; 36, E. hidakai, L 10; 37, E. borneoensis, L 11; 38, E. borneoensis, L 07; 39 – 48, E. timidus; 39, L 17; 40, L 13; 41, L 08; 42, L 02; 43, L 23; 44, L 21; 45, L 22; 46, L 18; 47, L 09; 48, L 06; 49, E. sabahensis, L 14; 50, E. cechovskyi, holotype; 51, E. cechovskyi, paratype; 52, E. gedeensis, holotype.

FIGURES 57 – 76. Prosternal process in ventral view. 57, Echinoaesalus hidakai, L 12; 58, E. hidakai, L 10; 59 – 62, E. borneoensis; 59, L 11; 60, L 01; 61, L 07; 62, L 16; 63, E. gedeensis, holotype; 64 – 67, E. timidus; 64, L 08; 65, L 02; 66, L 17; 67, L 21; 68, E. sabahensis, L 14; 69, E. cechovskyi, L 28; 70 – 73, E. timidus; 70, L 09; 71, L 06; 72, L 20; 73, L 13; 74, E. sabahensis, after Krikken 2008; 75, E. cechovskyi, paratype; 76, E. javanus, after Krikken (2008), holotype.

FIGURES 111 – 124. 111 – 123, Echinoaesalus cechovskyi, habitus and characters; 111 – 117, male holotype; 118 – 123, female paratype; 111, 118, dorsal view; 112, 119, lateral view; 113, 120, head in oblique view; 114, 121, head in dorsal view; 115, part of metasternum to show a small furrow near mesocoxae; 116, 122, scutellum in dorsal view; 117, abdominal ventrites, showing pair of large sulci to receive legs; 123, metasternum and ventrites, showing furrows and sulci; 124, E. timidus, holotype in lateral view (photograph by Jan Krikken).

FIGURES 90 – 102. Aedeagus in dorsal, left lateral, ventral, and right lateral views under same scale (scale bar 1 mm). 90, Echinoaesalus hidakai, L 12, western Malaysia; 91, E. borneoensis, L 11, Borneo; 92, E. borneoensis, L 01, Borneo; 93 – 98, E. timidus; 93, L 08; 94, L 02; 95, L 17; 96, L 23; 97, L 21; 98, L 22; 99, E. sabahensis, L 14, Borneo; 100, E. timidus, L 18; 101, E. cechovskyi, holotype, western Malaysia; 102, E. gedeensis, holotype, Java. Arrows directed to ends of parameres.

FIGURES 107 – 110. Female genitalia under same scale (scale bar 1 mm). 107, Echinoaesalus timidus, L 09; 108, E. cechovskyi, paratype, Singapore; 109, E. timidus, L 25; 110, E. timidus, L 20. Abbreviations: st, stylus; lv, last abdominal ventrite; mo, median oviduct; bd, bursal duct; bc, bursa copulatrix; sd, spermathecal duct; s, spermatheca; sg, spermathecal gland; ag, accessory gland.