Schizotetranychus gilvus Ehara & Ohashi 2005, sp. nov.

Schizotetranychus gilvus sp. nov.

(Japanese name: Koto­matahadani)

(Figs. 1–16)

Diagnosis — This species is distinct from any other known members of the genus in having tibiae I and II with 9 and 8 tactile setae, respectively, and the aedeagus with somewhat triangular shaft and conspicuous pick­shaped terminal knob. It resembles S. zhangi Wang & Cui, 1992 which is known only from females collected in Yunnan, China, on Quercus gilliana Rehder & E.H. Wilson. However, the female of S. gilvus sp. nov. differs from that of S. zhangi in the following points:

1) Tibia II with 8 tactile setae (7 tactile setae in zhangi).

2) Each empodium with 2 dorsal appendant hairs on each of claw­like parts (1 dorsal appendant hair in zhangi).

3) Area immediately anterior to genital flap with longitudinal to curved striae (transverse striae in zhan g i).

Female — Body greenish yellow in color, with 2 dark lateral spots on each side. Rostrum reaching middle to distal end of genu I (Fig. 1). Palpus with spinneret about twice as long as broad; dorsal sensillum (solenidion) rod­like, with subparallel sides (Fig. 2).

Peritreme L­ or U­shaped distally (Fig. 5). Dorsolateral opisthosomal setae (c2 to f2) much longer than dorsocentral opisthosomals (c1 to h1); humeral seta (c3) very long, approximately 3 times the length of c1; each of c1 to f1 shorter than distance to base of seta next behind (Fig. 1).

Opisthosomal striae on dorsocentral region transverse, with lobes approximately semicircular. Genital flap with transverse striae; area immediately anterior to flap with longitudinal to curved striae.

Numbers of setae and solenidia (in parentheses) on leg segments: coxae 2–2–1–1, trochanters 1–1–1–1, femora 9–7–4–4, genua 5–5–3–3, tibiae 9(1)–8–6–7, tarsi 14(1)+ 2 dupl.–12(1)+ 1 dupl.–9(1)–9(1). Tarsus I with 5 tactile setae proximal to proximal set of duplex setae, and 1 solenidion near level of proximal duplex set (Fig. 9); tarsus II with 2 tactile setae and 1 solenidion proximal to duplex setae (Fig. 10). Empodia with 2 dorsal appendant hairs on each claw­like part; the upper dorsal appendant much shorter than the lower (Figs. 13–14).

Measurements (mean, n=10): length of body (including rostrum) 526, width of body 284; lengths of setae (mean±SE): v2 53.6±0.7, sc1 52.0±0.5, sc2 67.4±1.0, c1 40.5±0.3, c2 55.7±0.7, c3 97.3±1.4, d1 39.3±0.3, d2 55.1±0.6, e1 39.6 ±0.5, e2 62.2±0.9, f1 40.4±1.1, f2 57.6±0.8, h1 53.8±1.2.

Male — Color similar to female. Palpus with spinneret subconical, variable in shape; doral sensillum very slender, subparallel­sided (Figs. 3–4).

Aedeagus with shaft somewhat triangular, the dorsal and ventral margins nearly straight; terminal knob pick­shaped, about 4.0 long; anterior projection of knob very small, acute; the posterior projection elongate, gently tapering; axis of knob forming slight angle with dorsal margin of shaft (Figs. 6–8).

Numbers of setae and solenidia (in parentheses) on leg podomeres: coxae 2–2–1–1, trochanters 1–1–1–1, femora 9–7–4–4, genua 5–5–3–3, tibiae 9(3)–8[rarely 7]–6–7, tarsi 13(3)+2 dupl.–12(1)+1 dupl.–9(1)–9(1). Tarsus I with 4 tactile setae and 2 solenidia proximal to proximal set of duplex setae, and 1 solenidion near level of proximal duplex set (Fig. 11); tarsus II with 2 tactile setae and 1 solenidion proximal to duplex setae (Fig. 12). Empodium I with 1 or 2 dorsal and 1 ventral appendant hairs on each claw­like part (Figs. 15–16). Empodia II–IV similar to those of female.

Measurements (mean, n=10): length of body (including rostrum) 437 (425); lengths of setae (mean±SE): v2 40.1±0.6 (37.9), sc1 38.7±0.8 (37.3), sc2 49.2±0.7 (48.0), c1 31.3±0.6 (28.0), c2 44.5±1.5 (38.7), c3 73.2±1.2 (74.3), d1 32.1±0.7 (30.6), d2 43.9±1.1 (38.7), e1 30.7 ±0.6 (27.7), e2 39.7 ±1.3 (33.8), f1 30.0±0.7 (28.4), f2 32.8±0.7 (31.6), h1 27.8±0.7 (26.5).

Type series — Holotype: male (NSMT­Ac 11888), Botanical Garden of Kyoto University, Sakyo­ku, Kyoto, Honshu, Japan, 7­X­2004 (K. Ohashi leg.), on Quercus gilva Blume (Fagaceae). Paratypes: 4 males (NSMT­Ac 11889–11892), data same as for holotype; 1 male (NSMT­Ac 11893) and 3 females (NSMT­Ac 11894), 14­IX­2004, other data same as for holotype; 4 females (NSMT­Ac 11895–11896), Kitauoyanishi­machi, Nara, Honshu, 18­IX­2004, other data same as for holotype; 2 males and 2 females (KUM), Takabatake­cho, Nara, 18­IX­2004, other data same as for holotype.

Other specimens — Six males and 6 females (Ehara’s private collection), Matsugasaki­hashikami­cho, Sakyo­ku, Kyoto, 27­III­2004 (K. Ohashi leg.), on Q. gilva.

Etymology — The specific name is taken from the Latin adjective gilvus meaning “pale yellow” or “yellowish”, referring to the body color.