Multivesicula zhengi sp. nov.

Figures 1–19, Tables 1, 2

Material examined. Holotype: female, (slide No. XJ-2016081-3), Northwest China, Xinjiang Province, Urumuchi City, Baiyanggou, 43°25’ N 87°09’E, elev. 2000 m, soil samples from coniferous forest, 4-IX-2016, C.W. Huang coll. Paratypes: 5 females (slides Nos. XJ-2016068, XJ-2016077-2, XJ-2016077-3, XJ-2016077-4, XJ-2016077- 5), same data as holotype. All type specimens are deposited in Shanghai Natural History Museum (SNHM) .

Diagnosis. Postantennal organ composed of 48–52 vesicles arranged in 4 irregular rows; pseudocelli formula of 11/122/11111: with one pair on Th. I and two pairs on each of Th. II and III; seta px on Abd. IV present, setae a2 and a4 on Abd. V as macrosetae; sensillum p3 on Abd. V weakly differentiated.

Description. Adult body 0.59 mm long on average (0.56–0.66 mm, n = 6), holotype 0.56 mm. Dorsal setae well differentiated into micro- and macrosetae (Figs 1, 7–10). Granulations on body coarse. Pso formula as 11/122/11111 from head to abdomen, 7–8 μm in diameter, type I (Figs 4, 18). On Th. I pso set behind seta m2, close to hind margin (Fig. 6). Th. II and III each with two pairs of pso, subdorsal one between setae p3/p4, close to p3, lateral one posterior to seta m5 (Figs 6–7); pso on Abd. I–IV posterior to seta p3 (Figs 8–11), on Abd. V between the borders of Abd. V and VI (Fig. 12).

Cephalic seta a0 and sd5 as mesosetae, 10–11 μm, c1 absent, oc2 as macroseta, 14–15 μm long (Fig. 2). Postantennal organ ellipse shaped, 15–16 μm long and 6–7 μm wide, composed of 48–52 round vesicles irregularly arranged in four rows, 48 on holotype (Figs 4, 18). Labrum with 4/5/4 setae. Labium with 5 papilla, 6 apical guard setae, 6 proximal setae, 4 basomedian setae, and 5 basolateral setae (Fig. 3).

Antenna (70–80 μm) shorter than head (90–100 μm), 70 μm in holotype. Antennal segment IV with five thickened sensilla a–e, without basal heel; sensilla a, c, e long and curved toward inner side, b straight and short, d small and short, curved toward inner side (Fig. 16). Small microsensillum, subapical organite and one apical vesicle present (Fig. 16). Antennal organ III (Fig. 16) consists of two small sensory rods concealed behind one large papilla and two thick sensory clubs bent toward each other, with four guard setae; one large ventral sensory club present (Fig. 17).

Legs short, without clavate tibiotarsal hairs (Fig. 19). Coxa, trochanter, femur and tibiotarsus with 3/7/7; 6/6/5; 10/10/10; 15/15/14 setae on leg I, II and III respectively. Claw 10 μm long (Fig. 19), with short empodial appendage (3–4 μm). Anal lobes with seta 12' and l3' (Fig. 15). Anal spines short, 10 μm long (Fig. 12).

Adult chaetotaxy given in Figs 6–15 and Table 1. Microsensilla present on Th. II–III, lateral sensilla thick, 17–19 μm long (Figs 6–7). Thorax with 0, 2, 2 ventral setae. Abd. I–III with 2+2 axial setae each segment, with setae m3 and m4 present (Figs 8–10). Abd. IV with setae m4 and px present, p1 as macrosetae (13–15 μm), p2 as microseta (8–10 μm) (Fig. 11). Abdominal segment V (Fig. 12) with sensillum p3 slightly differentiated, 10–14 μm in length; seta a2 (20–22 μm) and a4 as macroseta (22–25 μm). Crescentic ridges on abdominal segment VI present (Fig. 12).

Ventral tube with 4+4 apical setae and 2+2 basal setae (Fig. 5). Abd. II, III and IV with 20, 22, and 26 ventral setae respectively (Figs 13–14). Female genital plate with 6+6 pregenital setae, 3 circumgenital setae, one pair of eugenital setae and 2 pairs of post-genital setae (Fig. 15).

1 seta m3 and m4 present; 2 seta m4 present; 3 seta px present, p1>p2; 4 setae a2 and a4 as macroseta; 5 sensillum p3 slightly differentiated, seta p4 as mesoseta; 6 female genital plate with 3 circumgenital and one pair of eugenital setae.

Distribution. China (Xinjiang), only known from the type locality.

Etymology. We dedicate this new species in honor of the late Professor Zhemin ZHENG (1932–2021) who was a well-known orthopterist for his great contribution to the knowledge of Chinese grasshoppers.

Remarks. The genus Multivesicula contains six species in the world: M. columbia Rusek, 1982, M. punctata Rusek, 1982 and M. dolomitica Rusek, 1982 described from Canada, M. giljarovi Rusek, 1982 from Russia, M. ampla Christiansen & Bellinger, 1980 from USA and M. aliciae (Palacios-Vargas & Díaz, 1996) from Mexico (Bellinger et al. 1996 –2021). Multivesicula zhengi sp. nov. can be easily distinguished from all above known species by the presence of one pair of pso on Th. I and two pairs of pso on Th. II, pso formula as 11/122/11111, the presence of seta m3 on Th. II and III and seta a2 on Abd. V, and the weakly differentiated sensillum p3 on Abd. V. The differences between all seven species in the genus are given in Table 2.