Epitrimerus fruticus, Xie & Chen, 2022

Xie, Manchao & Chen, Zhenning, 2022, Two new species of eriophyoid mites (Acari: Eriophyoidea) from Qilian Mountain National Park, China, Zoological Systematics 47 (4), pp. 336-340 : 336-337

Epitrimerus fruticus sp. nov. ( Figs 1–4 )

Diagnosis. The new species is distinct by the large broad frontal lobe duckbilled in lateral view. Besides that, the mites exhibit characters as following: body fusiform, yellowish-brown in color; gnathosoma projecting obliquely; shield with median line, admedian and submedian lines present; scapular tubercles set well ahead of rear shield margin, basal axes diagonal to the body, scapular setae projecting forward and up; coxisternal plates with a few lines, prosternal apodeme present; leg with tarsal empodium simple, 6-rayed; tarsal solenidion without knob; opisthosoma dorsally with 40–49 semi-annuli, forming a low middorsal longitudinal ridge and two lateral ridge, ventrally with 65–77 semi-annuli, with round or taper microtubercles on rear annular margins; setae h1 present; female genitalia coverflap with 8 longitudinal ridges.

Description. Female (n = 20). Body fusiform, yellowish-brown in color, 215 (170–215), 80 (65–80) wide, 70 (58–70) thick. Gnathosoma 25 (25–27), projecting obliquely; pedipalp coxal setae (ep) 4 (3–4), dorsal pedipalp genual setae (d) 7 (6–8). Prodorsal shield 50 (50–52), 68 (60–75) wide, covered with a large broad frontal lobe over gnathosoma base, duckbilled in lateral view, 10 (10–12). Shield with median line and admedian lines present, but anterior 1/3 obscure; submedian lines connected with scapular tubercles. Scapular tubercles set well ahead of rear shield margin, basal axes diagonal to the body, 24 (20–24) apart; scapular setae (sc) 10 (8–12), projecting forward and up. Coxigenital plants with 10 (9–10) semi-annuli between coxae and genitalia. Coxal plates I with long lines and II with short lines, anterolateral setae on coxisternum I (1b) 8 (6–8), 10 (10–12) apart; proximal setae on coxisternum I (1a) 20 (15–20), 6 (6–7) apart; proximal setae on coxisternum II (2a) 30 (25–32), 23 (20–25) apart; prosternal apodeme present, 8 (8–9). Leg I 34 (31–36), trochanter 3 (2–3), femur 13 (12–13), basiventral femoral setae (bv) 13 (13–15); genu 5 (4–5), antaxial genual setae (l'') 28 (25–28); tibia 7 (7–8), paraxial tibial setae (l')7 (7–8), located at the inner lateral side 1/2 from base; tarsus 6 (6–7), paraxial fastigial tarsal setae (ft') 22 (20–22), antaxial fastigial tarsal setae (ft'') 22 (20–22); tarsal empodium (em) 7 (7–8), simple, 6-rayed; tarsal solenidion (ω) 8 (8–9), tapering, not knob in the end. Leg II 33 (30–34), trochanter 3 (2–3), femur 13 (12–13), basiventral femoral setae (bv) 15 (13–20); genu 5 (4–5), antaxial genual setae (l'') 12 (10–14); tibia 6 (no range); tarsus 6 (6–7), paraxial fastigial tarsal setae (ft') 7 (7–10), antaxial fastigial tarsal setae (ft'') 22 (22–25); tarsal empodium (em) 7 (7– 8), simple, 6-rayed; tarsal solenidion (ω) 8 (8–9), tapering, not knob in the end. Opisthosoma dorsally with 42 (40–49) semi-annuli, covered with waxy materials; waxy belts usually extend from rear shield to end suggesting that there seem to be three longitudinal ridges on dorsal annuli; ventrally with 65 (65–77) semi-annuli, with round and irregular taper microtubercles except caudal 5–6 ventral semi-annuli with elongated microtubercles; setae c2 30 (30–35) on ventral semi-annulus 12, 58 (58–60) apart; setae d 35 (30–40) on ventral semi-annulus 25, 36 (36–40) apart; setae e 21 (15–25) on ventral semi-annulus 39, 17 (17–20) apart; setae f 25 (20–30) on 6 ventral semi-annulus from rear, 25 (22–25) apart. Setae h1 4 (3–4), 5 (5–6) apart; setae h2 50 (50–60), 10 (9–10) apart. Female genitalia 13 (13–15), 23 (22–23) wide, coverflap sculptured with 8 longitudinal ridges, setae 3a 15 (15–17), 13 (12–14) apart.

Male. Unknown.

Material examined. Holotype ♀, from Potentilla fruticosa L. ( Rosaceae ), Laohugou Vall Area, Menyuan, Qinghai, China, 37°29´51"N, 101°34´26"E, elev. 3166 m, 30 July 2020, coll. Manchao Xie. Paratypes. 9♀, same data as holotype; 10♀, Qihankai Scenic Area, Xianmi, Menyuan, Qinghai, China, 37°09´30"N, 102°01´58"E, elev. 2701 m, 27 July 2020, coll. Manchao Xie.

Biology. The mites are vagrant on the undersurfaces of leaves, no visible damage was seen.

Etymology. The specific name is from Latin frutic, deriving from the host plant, with masculine ending.

Remarks. The genus Epitrimerus Nalepa, 1898 arranges about 176 species worldwide ( Amrine et al., 2003; Hong et al., 2010; Xue & Hong, 2011; Ou et al., 2014; Varandi et al., 2019), of which 40 species are distributed in China.

The new species is the second species of the genus Epitrimerus found on Potentilla plants, besides the E. jaceae Liro, 1943 which infecting P. erecta and P.reptans ( Davis et al., 1982) . But the new species can be easily differed from the latter by the prodorsal shield with median line present (vs. absent in E. jaceae ), tarsal empodium 6-rayed (vs. 4-rayed in E. jaceae ).

The new species is similar to E. spiraeae Kuang, 1995 by having tarsal empodium 6-rayed and similar host plant in Rosaceae , but can be differed from the latter by the prodorsal shield with median line present (vs. absent in E. spiraeae ), opisthosoma with dorsal semi-annulus broader than ventral semi-annulus (vs. subequal in E. spiraeae ).

Figures

Figures 1–4. Epitrimerus fruticus sp. nov., female. 1. Lateral view. 2. Dorsal view. 3. Coxal-genital region. 4. Empodium (enlarged). Scale bars=10μm.