Synchroa melanotoides Lewis, 1895

Hsiao, Yun, Ondřej Konvička & Chiun-Cheng Ko, 2018, The world fauna of Synchroidae Lacordaire, 1859 (Coleoptera, Tenebrionoidea, Synchroidae), European Journal of Taxonomy 407, pp. 1-33 : 17-19

Synchroa melanotoides Lewis, 1895

Figs 3C–D , 4B, H , 5C–D, N , 6F–I

Synchroa melanotoides Lewis, 1895: 263 .

Diagnosis

This species resembles Synchroa elongatula Nikitsky, 1999 in pronotal configuration with lateral sides of the pronotum margined in posterior one-third to one-fourth, but it can be also separated by its reddishbrown antennae and legs; stout elytra; prosternal process with long oval apex; aedeagus: paramere more slender, with lateral sides gradually narrowed apically. It resembles S. punctata in the shape of the aedeagus, but can be separated in the body being closely covered with yellowish simple setae; eyes larger; pronotum margined in posterior one-third to one-fourth of lateral sides; prosternal process thinner; dorsal groove of aedeagus narrower basally.

Material examined

JAPAN: 1 ex., Matsum, date and collector unknown ( HUM); 1 ♂, Kuzukawa, Hiraka-cho , Aomori Pref., 10 Aug. 1957, K. Shimoyama leg. ( NMNS); 2 ♀♀, 1 ex., Kuzukawa, Hiraka-cho , Aomori Pref., 18 Aug. 1957, K. Shimoyama leg. ( NMNS); 1 ♀, Kuzukawa, Hiraka-cho , Aomori Pref., 20 Aug. 1957, K. Shimoyama leg. ( NMNS); 1 ♂, Kuzukawa, Hiraka-cho , Aomori Pref., 21 Aug. 1957, K. Shimoyama leg. ( NMNS); 1 ♀, Mennoki-toge, Tsugu , Aichi Pref., 27–28 Jul. 1974, H. Yamada leg. ( NMNS); 1 ♂, Kamitakara-mura , Gifu Pref., 11 Aug. 1979, M. Satô leg. ( NMNS); 1 ♀, Ohboshi-yama , Tsushima , 30 Jun. 1980, N. Ohbayashi leg. ( NMNS); 1 ex., Taniyama, Ohno-shi , Fukui Pref., 5–6 Aug. 1984, M. Saitȏ leg. ( OKCZ); 1 ex., Kobiyaku Imaichi , Tochigi Pref., 20 Jul. 1986, K. Emoto leg. ( OKCZ); 1 ex., Mt. Gomadan-zan, Ryûjin-mura, Hidaka-gun , Wakayama Pref., 10 Jul. 1988, H. Miyazaki leg. ( OKCZ); 2 ex., Uchinokaya, Ina-shi , Nagano Pref., collected on host ( Juglans mandshurica var. sachalinensis ) 1 May 1990, emerged 11–13 Jun. 1990, R. Toyoshima leg. ( OKCZ); 2 ex., Mt. Asuwa, Fukui-shi , Fukui Pref., 18 Jun. 1994, M. Saitȏ leg. ( OKCZ); 1 ex., Jyȏzan-kei, Minami-ku, Sapporoshi , Hokkaido, 7 Aug. 2008, R. Toyoshima leg. ( OKCZ); 1 ♀, Fushimiinari, Fushimi , Kyoto Pref., 10 Jul. 2013, S. Makita leg. ( YHC); 2 ♂♂, 1 ♀, Kanayama [timber-yard], 43.510 N, 143.149 E, Mianmifurano-chô, Sorachi-gun , Hokkaido, 4 Aug. 2016, N. Kikuchi leg. ( YHC).

Redescription

COLOUR. Body completely blackish-brown. Antennae and legs somewhat reddish-brown.

Male ( Fig. 3C )

MEASUREMENTS. Length: 8.25–10.50 mm; width: 2.00– 2.5 mm.

BODY. Elongate, slightly flattened, elytra rather strongly narrowed posteriorly, covered with yellowish, elongate and decumbent setae.

HEAD. Eyes lateral, large, emarginate in front of antennal insertions, ratio of eye diameter to interocular space 1.0: 1.2–1.3. Antennae filiform, when directed backwards exceeding the humeri of elytra. Scape cylindrical, wider than other antennomeres, pedicel short, antennomere III–XI somewhat clavate, XI longest, length ca 3.1–4.1 times maximum width. Length ratio of antennomeres as follows: 1.60: 1.00: 2.60:2.50: 2.10: 2.10: 2.05: 2.05: 1.85:1.75: 2.85. Apical maxillary palpomere securiform, apical margin moderately rounded, terminal angle somewhat obtuse. Surface lustrous, densely and coarsely punctate; interspaces slightly narrower than puncture diameter.

PRONOTUM. Truncate anteriorly, anterior edge slightly concave, bisinuate posteriorly, with obtuse median lobe, width ca 1.4–1.5 times length, ca 1.5–1.6 times as wide as head. Lateral sides rounded and strongly narrowed in anterior two-thirds toward head, subparallel in posterior one-third, margined in posterior one-third to one-fourth. Anterior angle rounded; posterior angle rectangular and obtuse. Disc slightly flattened medially, surface lustrous, densely and coarsely punctate; spaces between punctures smaller than puncture diameter. Scutellum width ca 1.4–1.6 times length.

ELYTRA. Elongate, narrowed posteriorly, apex rounded, as wide as pronotal width at humeri, length ca 2.4–2.6 times width, surface lustrous. Disc covered with oval punctures, denser in lateral and basal part; interspaces wider than puncture diameter. Nine faint traces of striae in each elytron from dorsal view, stria I fused with II ( Fig. 4B ), gradually shortened outwards, elytral striae indistinct in some specimens. Prosternum before procoxae about as long as shortest diameter of procoxae. Prosternal process long, margined laterally, long oval; length behind procoxae shorter than or as long as width between procoxae. Width between procoxae ca 0.2 times transverse coxa diameter. Mesoventrite with shallow, oval mesoventral cavity, moderately punctate. Abdominal ventrite V subtruncate, with lateral sides nearly straight to slightly rounded ( Fig. 4H ); sternite VIII concave in middle of apical edge, forming two roundly angular lobes on both sides, moderately pubescent apically ( Fig. 5D ); sternite IX without spiculum gastrale on apical edge ( Fig. 5N ); tergite VIII without median strut on apical edge, rounded apically or emarginate in middle, moderately pubescent apically ( Fig. 5C ); tergite IX and X completely fused, rounded apically, densely pubescent on apical edge ( Fig. 5N ).

LEGS. Slender. Tarsomeres simple, tarsal formula 5-5-4. The longest spur of hind tibiae ca 0.2 times as long as first tarsal segment; length ratio of tarsomeres as follows: 2.10: 1.00: 0.50: 0.70 (measured without claws). Claws simple.

AEDEAGUS ( Fig. 6F–I ). Lanceloate, basal piece curved dorsally, lateral sides roundly arcuate, narrowed basically. Parameres narrowly separated apically and with a groove in dorsal median part, lateral sides straight, slightly narrowed apically, abruptly strongly narrowed at apex, length ca 3.0–3.9 times maximum width. Median lobe elongate, tapered, strongly narrowed apically in apical half.

Female ( Fig. 3D )

MEASUREMENTS. Length: 10.25–12.00 mm; width: 2.5–3.25 mm.

BODY. Similar to males.

HEAD. Eyes smaller than in male, ratio of eye diameter to interocular space 1.0:1.4–1.5. Antennae shorter in male, when directed backwards extending the posterior edge of pronotum, antennomere XI ca 2.8 times as long as maximum width. Length ratio of antennomeres as follows: 1.90: 1.00: 2.10:2.30:2.25: 2.10:2.10: 2.05: 2.00: 1.90: 2.60.

PRONOTUM. Ca 1.5 times wider than length, ca 1.5–1.6 times as wide as head.

ELYTRA. Slightly wider than in male, as wide as pronotal width at humeri, length ca 2.5 times width.

OVIPOSITOR. Paraproct elongate, ca 3.0 times length of coxite, sides straight and subparallel; proctiger subtruncate.

Notes

This is a common species in Japan, which can be captured at light (S. Makita, personal communication). Larvae can be collected under the bark of decaying oak wood ( Hayashi 1975) and walnut trees, Juglans mandshurica var. sachalinensis . Nikitsky (1999) mentioned that antennomere XI of this species is ca 2.5–2.8 times as long as the width, whose data were followed by Hsiao (2015) and Hsiao et al. (2016). However, our examination shows that this species has a wider variation in the length of antennomere XI than previously documented.

Distribution

Russia (Far East); Japan; Korea; China (Jilin) ( Löbl 2008).

Notes

Nikitsky (1999) and Löbl (2008) indicated this species as present in Korea; these data were neglected by Hsiao (2015) and Hsiao et al. (2016). Thus, we herein list Korea in the distribution. Additionally, Löbl (2008) referred to China (Jilin prov.); however, we cannot find any further literature or specimen to confirm this assumption.

Figures

Fig. 3. Habitus, dorsal view. A–B. Synchroa punctata Newman, 1838. C–D. S. melanotoides Lewis, 1895. E–F. S. chinensis Nikitsky, 1999. G–H. S. formosana Hsiao, 2015. I. S. elongatula Nikitsky, 1999. J–K. Synchroina tenuipennis Fairmaire, 1898. L. Thescelosynchroa pangu (Hsiao, Li, Liu & Pang, 2016) gen. et comb.nov.A, C, E, G, I, J, L = ♂. B, D, F, H, K = ♀. Scale bars: 5.0 mm.

Fig. 4. Elytron and abdominal ventrite V. A–F. Elytron. G–L. Abdominal ventrite V of ♂♂. — A, G. Synchroa punctata Newman, 1838. B, H. S. melanotoides Lewis, 1895. C, I. S. chinensis Nikitsky, 1999. D, J. S. formosana Hsiao, 2015.E, K. S. elongatula Nikitsky, 1999. F, L. Synchroinatenuipennis Fairmaire, 1898. Scale bars: 0.5 mm.

Fig. 5. Abdominal sternite VIII–IX and tergite VIII–X of ♂♂. A, C, E, G, I, K. Abdominal tergite VIII. B, D, F, H, J, L. Abdominal sternite VIII. M–R. Abdominal sternite IX, and fused tergite IX and X. — A–B, M. Synchroa punctata Newman, 1838. C–D, N. S. melanotoides Lewis, 1895. E–F, O.S.chinensisNikitsky, 1999.G–H,P.S.formosana Hsiao,2015.I–J,Q. S.elongatulaNikitsky,1999. K–L, R. Synchroinatenuipennis Fairmaire, 1898. Scale bars: 0.5 mm.

Fig. 6. Aedeagus. A–E. Synchroa punctata Newman, 1838. F–I. S. melanotoides Lewis, 1895. J–K. S. chinensis Nikitsky, 1999. L. S. formosana Hsiao, 2015. M–N. S. elongatula Nikitsky, 1999. O–P. Synchroina tenuipennis Fairmaire, 1898. Q–R. Thescelosynchroa pangu (Hsiao, Li, Liu & Pang, 2016) gen. et comb. nov. — A–C, F–G, J, L–M, O, Q. Dorsal view. D–E, H–I, K, N, P, R. Lateral view. Scale bars: 0.5 mm.