Tetra sorbusis sp. nov.

(Fig. 3)

Description

FEMALE: (n = 4) Body fusiform, 210 (190–215) long, 70 (68–72) wide, 65 (64–67) thick; light yellow. Gnathosoma 20 (18–21), projecting obliquely down. Prodorsal shield 45 (44–46) long, 53 (52–55) wide; subtriangular; frontal lobe acuminate; admedian lines present and connected at base. Scapular tubercles on rear margin, 30 (28–31) apart, scapular setae (sc) 15 (14–15) projecting posterior. Coxal area smooth; anterolateral setae on coxisternum (1b) 5 (5–6), proximal setae on coxisternum (1a) 30 (28–32), proximal setae on coxisternum (2a) 45 (42–48). Prosternal apodeme present. Legs with usual series of setae. Legs 35 (33–37), femur 11 (10–11), basiventral femoral setae (bv) 11 (10–12); genu 6 (5–6), antaxial genual setae (l'') 23 (22–25); tibia 9 (8–9), paraxial tibial setae (l') 3 (3–4), setae located 1/3 from dorsal base; tarsus 6 (5–6); tarsal empodium simple, 4­rayed, tarsal solenidion knobbed. Legs 31 (29–33), femur 10 (9–10), basiventral femoral setae (bv) 9 (8–9); genu 5 (4–5), antaxial genual setae (l'') 10 (9–11); tibia 7 (6–7); tarsus 6 (5–6); tarsal empodium simple, 4­rayed, tarsal solenidion knobbed. Opisthosoma: dorsal opisthosoma with 30 (28–31) annuli, smooth, ventrally with 43 (40–45) microtuberculate annuli. Setae c2 23 (21–24) on ventral annulus 8 (8–9); setae d 42 (40–44) on ventral annulus 15 (14–16); setae e 17 (15–18) on ventral annulus 25 (24–27), setae f 26 (23–29) on 5th ventral annulus from rear. Setae h1 3 (3–4). Female genitalia 19 (18–20), 22 (21–24) wide, coverflap with 8 longitudinal ridges, proximal setae on coxisternum (3a) 15 (13–16).

MALE: (n = 4) 160 (156–163) long, 51 (50–51) wide; genitalia 5 (5–6) long, 18 (18–19) wide, proximal setae on coxisternum III (3a) 12 (10–14).

Types

Holotype, female, China: Shaanxi Province, Mei County, Taibai Mountain, 34°01.51’N, 107°48.36’E. September 1, 2004, from Sorbus sp. (Rosaceae), coll. Xue, Xiao­Feng & Song, Zi­Wei. Paratypes, 3 females and 4 males, with the same data as holotype.

Relation to host

Mites are vagrant on leaf surface, causing no apparent damage.

Etymology

The specific designation sorbusis is from the genetic name of host plant, Sorbus.

Remarks

This species is similar to Tetra toona Huang, 2001, but can be differentiated by prodorsal shield with admedian lines connected at base (admedian lines connected at basal 2/ 3 in T. toona), opisthosoma with 30 dorsal annuli (with 47 annuli in T. toona) and fore tibial setae (l'), hind femoral and patellar setae present (absent in T. toona).