Lycocerus rhagonychiformis

Lycocerus rhagonychiformis (Wittmer, 1983)

(Figs 1A–E, 2A–C, 3A–B, 4)

Athemellus rhagonychiformis Wittmer, 1983: 169 (original description).

Lycocerus rhagonychiformis: KAZANTSEV & BRANCUCCI (2007): 253 (new combination).

Type locality. Taiwan, New Taipei City, NE slope of Lalashan.

Type material examined. PARATYPES: 5 spec., ‘TAIWAN / NE slope of Lalashan, 1900m / Taipei Hsien / 7. iv. 1981 / T. Shimomura leg.’ (NHMB); 1 ♀, ‘TAIWAN / Fenchihu / 1400m / 10. vi. 1977 / J & S. Klapperich leg.’ (NHMB). Additional material examined. TAIWAN: 1 ♂, ‘FORMOSA [=TAIWAN] / Lake Yenyanfu / Ilan Hsien / 29. iv. 1982 / N. Ohbayashi leg.’ (KURA); 1 ♂ 1 ♀, ‘TAIWAN / Dakuanshan [=Lalashan] / Taoyuan Hsien / 4. iv. 1991 / Y. Okushima leg.’ (KURA); 1 ♂ 2 ♀♀, ‘TAIWAN / Mt. Lalashan / Taoyuan Hsien / 4. iv. 1991 / T. Kishimoto leg.’ (KURA); 1 ♀, ‘TAIWAN / T’ien-ch’ih / 2610m / Hsiao-hsueh Shan / Ho-p’ing Hsiang / T’aichung Hsien / 24. v. 1991 / A. Saito leg.’ (CMIC); 2 ♂♂ 3 ♀♀, ‘TAIWAN / Chung-hsueh Shan (Erh-san-ling Lin-tao [=230 Forest trail]) / 2450–2500m / Tai-an Hsiang / Miao-li Hsien / 24. v. 1991 / A. Saito leg.’ (CMIC); 3 ♂♂ 2 ♀♀, ‘TAIWAN / Anma Shan / 2160–2300m / Ho-p’ing Hsiang / T’aichung Hsien / 25. v. 1991 / A. Saito leg.’ (CMIC); 1 ♀, ‘TAIWAN / Chia-li Shan / 2600–2650m / Tai-an Hsiang / Miao-li Hsien / 26. v. 1991 / A. Saito leg.’ (CMIC); 2 ♂♂ 3 ♀♀, ‘TAIWAN / Chia-li Shan / 2600–2850m / Tai-an Hsiang / Miao-li Hsien / 27. v. 1991 / A. Saito leg.’ (CMIC); 1 ♂, ‘TAIWAN / Lo Shan / 2100–2150m / Wu-feng Hsiang / Hsin-chu Hsien / 29. v. 1991 / A. Saito leg.’ (CMIC); 1 ♀, ‘TAIWAN / Kuan-wu / 2000m / Wu-feng Hsiang / Hsin-chu Hsien / 29. v. 1991 / A. Saito leg.’ (CMIC); 1 ♂, ‘TAIWAN / Lancanshan / Ilan / 26. iv. 2014 / L. Huang leg.’ (YHC); 3 ♀♀, ‘TAIWAN / Jengchin Historic Trail / Ilan / 26. iv. 2014 / Y. Hsiao leg.’ (YHC); 1 ♂, ‘TAIWAN / Dabaishan / Ilan / 14. iv. 2015 / L. Huang leg.’ (YHC); 1 ♂ 1 ♀, ‘TAIWAN / Chiarouhu / Ilan / 25. iv. 2015 / F.-C. Hsu leg.’ (YHC); 1 ♀, ‘TAIWAN / Taipingshan / Ilan / 9. v. 2015 / C.-F. Hsu leg.’ (YHC).

Redescription. Coloration. Several color forms are presented: (1) nearly black, with basal parts of antennae and femora, and apical parts of tibiae yellowish (Figs 1A, 1D); (2) nearly black (Fig. 1B); (3) eyes and head black; antennae brown, with first two segments yellowish; pronotum completely black or dark yellow, with a black marking in middle; elytra fuscous, with large and thick pale yellow longitudinal stripe on each elytron; legs completely dark yellow or with apical parts of femora blackish; tibiae and tarsi with blackish tinge; prosternum dark yellow, meso-, metaventrites and abdomen black, with the margin of abdominal ventrites pale yellow (Fig. 1C); (4) nearly black, with basal parts of antennae and legs yellowish (Fig. 1E). Body closely covered with fine yellowish pubescence; anterior margin of clypeus fringed with pale bristles; antennae, elytra and legs with some yellowish bristles intermingled with primary pubescence.

Male (Figs 1A–C). Head nearly as long as wide; vertex faintly hollowed, depressed along apical margin of clypeus and in lateral areas before eyes; surface densely and finely punctate and semilustrous; anterior margin of clypeus arcuate and faintly indented in middle; eyes not so large, globular and slightly prominent, ratio of eye diameter to interocular space 1: 4.0–6.0 (mostly 4.5–5.0); terminal labial palpomeres rounded axe-shaped; terminal maxillary palpomeres rounded axe-shaped; antennae filiform, extending to apical third of elytra, antennomere I clavate, II short and a little expanded apicad, III to XI subcylindrical, all antennomeres without groove, ratio of lengths of antennomeres as follows: 200: 100: 170: 200: 225: 225: 225: 215: 200: 170: 180.

Pronotum subquadrate, about 0.80–0.90 (mostly 0.80) times as wide as head, nearly as long as wide; anterior and posterior margins moderately arcuate; lateral margins feebly sinuate, slightly converging posteriorly or subparallel; anterior angles rounded; posterior angles obtuse; dorsum convex in postero-lateral and hollowed in antero-lateral areas; medio-longitudinal groove distinct in posterior half; surface smooth and semilustrous. Scutellum triangular with rounded apex.

Elytra conjointly about 1.6–1.7 (mostly 1.7) times as wide as pronotum, about 3.0 times as long as wide, sides subparallel; surface densely and finely punctate and semilustrous.

Legs moderately slender; femora mostly straight; tibiae mostly straight, with basal part feebly arcuate; claws simple.

Aedeagus (Figs 2A–C). Ventral process expanded apically, apex curved inwards, basal part broad and extending inwards onto ventral side; dorsal plate of each paramere longer than ventral process, subtruncated, apical margin with some hairs on it, concave on inner margin. Laterophyse slender with obtuse apex. Inner sac swollen apically, and somewhat shorter than tegmen.

Length: Body length: 4.50–5.50 mm; width: 0.75–1.00 mm.

Female (Figs 1D–E). Similar to male. Body wider than in male. Eyes somewhat smaller than in male, ratio of eye diameter to interocular space 1: 5.2. Antennae distinctly shorter than in male, extending to elytral midlength, ratio of lengths of antennomeres as follows: 155: 100: 130: 170: 170: 160: 155: 150: 135: 130: 150. Pronotum about 0.90–0.95 (mostly 0.90) times as wide as head, about 0.93 times as long as wide. Elytra conjointly about 1.6–1.9 (mostly 1.7–1.8) times as wide as pronotum, about 2.8 times as long as wide. Claws simple. Abdominal ventrite VII widely emarginate on each side of terminal margin, forming subtriangular lateral lobes, median lobe indistinct (Fig. 3A).

Female genitalia (Fig. 3B). Vagina stout, and abruptly extended apically as long and thick duct; diverticulum and spermathecal duct arising from apex of long duct of vagina; diverticulum moderately thin and spiral; spermathecal duct shorter than diverticulum; spermatheca provided with thin spiral tube, which is longer than diverticulum; accessory gland thin, shorter than spermathecal.

Body length: 4.25–5.25 mm; width: 1.00– 1.25 mm.

Variation. The shape of pronotum is variable, from inverse trapezoid to square.

Differential diagnosis. The nearly black form resembles L. nigripennis (Pic, 1938) and the multi-color form resembles L. wenchuani sp. nov., L. hanatanii (Okushima, 1996), L. ueharaensis (Okushima, 1996) and L. maculiceps (Wittmer, 1983) in appearance. It can be distinguished from L. nigripennis by longer antennae, sparsely pubescent body, and aedeagus: subtruncated apical margin and concave inner margin of dorsal plate and longer laterophyse. From L. wenchuani sp. nov., L. hanatanii, L. ueharaensis and L. maculiceps, it differs in the combination of the following characters: completely black head, dark yellow legs, abdominal ventrite VII of females with median lobe not well developed, aedeagus: ventral process expanded apically, the apex curved inwards; dorsal plate longer than ventral process, with truncated apical margin; slender laterophyse, with an obtuse apex, visible in lateral view.

Distribution (Fig. 4). Taiwan (endemic).

Remarks. Judging by our examination and original description, all of the type series belong to the color form (4).

This species is distributed in the northern to central area of Taiwan at mid to high altitude (1400–2800 m). It appears mainly from late spring to early summer according to the label data.