Neomicrodispus lucani Rahiminejad & Seyedein, 2020

Seyedein, Sarina, Rahiminejad, Vahid & Nadimi, Ahmad, 2020, Two new species of microdispid mites (Acari: Heterostigmata: Pygmephoroidea) associated with Lucanus ibericus (Coleoptera: Lucanidae), Acarologia 60 (3), pp. 595-606 : 600-604

Neomicrodispus lucani Rahiminejad & Seyedein sp. nov.

Zoobank: AC91F8E7-794C-4C96-B19C-97A7FD76E88C

( Figures 4–6 )

Diagnosis — The new species is characterized by having all dorsal setae pointed and sparsely barbed; setae 4 a absent; setae cha and m subequal; setae e and h 2 subequal; setae ps 1 and ps 3 subequal and two times longer than ps 2.

Description — Female. Length of body (including gnathosoma) 182 (175–184), width 98 (94–103).

Gnathosoma ( Figs 4A & B ) – Length of gnathosoma 23 (22–23), width 15 (14–15); without dorsal median apodeme; cheliceral setae cha 11 (10–12) smooth and pointed; postpalpal setae (pp) 3 (3) needle-like, located laterad bases of cha. Setae dFe 7 (6–7) and dGe 4 (3–4) smooth, pointed, dFe longer than dGe; subcapitular setae m 10 (10–11) smooth and pointed; accessory setigenous structure indiscernible; pharyngeal pump system ( Fig. 4C ) with three pumps, second pharyngeal pump large, subrectangular and transversely striated, pharyngeal pumps 1 and 3 reduced and bow-shaped; pharyngeal pump 1 clearly separated from pharyngeal pump 2.

Idiosomal dorsum ( Fig. 4A ) – Body oval; prodorsum only slightly covered by anterior part of tergite C; oval stigmata and related tracheal trunks visible; trichobothria with long stem, clavate, weakly barbed, with two short apical projections; seta sc 2 24 (23–27), barbed; idiosomal length 155 (147–158); posterior margins of tergites C, D, EF and H tanned and with row of U-shaped elevations; all dorsal hysterosomal setae sparsely barbed and pointed; tergite C with two pairs of setae c 1 38 (36–39) and c 2 38 (35–39), setae c 1 and c 2 subequal; tergite D with setae d 40 (36–41), cupuli ia indiscernible; tergite EF with two pairs of setae e 17 (17–18) and f 39 (37–41), bases of setae e not associated with ridges and one pair of round porous areas situated besides of the base of setae e, distance e -f subequal to f -f; tergite H with setae h 1 31 (29–32), h 2 16 (15–16), cupuli ih round and placed posteriad seta h 2; all dorsal setae extended from posterior border of their tergites. Distances between dorsal setae: sc 2 – sc 2 33 (30–34),

c 1 – c 1 29 (28–32), c 2 – c 2 74 (70–77), c 1 – c 2 21 (20–23), d–d 20 (18–21), e–e 61 (59–66), e–f 19 (18–21), f –f 21 (20–22), h 1 – h 1 32 (30–33), h 2 – h 2 51 (50–53), h 1 – h 2 9 (9–10).

Idiosomal venter ( Figs. 4B ) – All apodemes (ap1 to ap4, apsej, appr and appo well developed, except ap5, absent; ap3 extending beyond bases of setae a 3; ap4 reach to bases of setae 3 b; ventral plates smooth. All ventral setae pointed and weakly barbed except smooth b; 4 setal formula of coxal fields: 2,2,3,2; setae 1 b and 2 a subequal, setae 2 b longest on anterior sternal plate; setae 3 a and 3 b subequal and longer than c 3; setae 4 a absent and setae 4 b longest setae on ventral plates; posterior part of poststernal plate tanned and with U-shaped elevations; posterior margin of aggenital plate almost straight; anterior genital sclerite (ags) small, bell-like and posterior genital sclerite (pgs) bow-shape; setae ps 1–3 smooth. Lengths of ventral setae: a 1

23 (21–23), 1 b 12 (11–13), 2 a 12 (10–12), 2 b 32 (31–32), 3 a 23 (21–25), 3 b 20 (19–21), 3 c 12 (12–13), 4 b 42 (40–45), 4 c 30 (29–32), ps 1 8 (7–10), ps 2 4 (4–5), ps 3 8 (7–10).

Legs ( Figs 5 & 6 ) – Leg I ( Fig. 5A ). Setal formula: (number of solenidia in parentheses): Tr1–Fe3–Ge4–TiTa15 (3). Tibiotarsus with five eupathidial setae tc ஥, tc ஧, ft ஥, ft ஧ and p ஧, setae

tc ஥ shorter than tc ஧, setae pv ஥, v ஥, l ஧ and pl ஧ barbed, other leg setae smooth, solenidia 1 ω 9 (8–9)

> φ 1 7 (6–7)> φ 2 3 (3–4), solenidion ω 1 weakly clavate, longer than other solenidia, solenidion φ 1 clubbed, solenidion φ 2 baculiform; genu with setae v ஥ and v ஧ barbed and subequal to l ஧ and shorter than l ஥; femur with setae d barbed and longer than subequal v ஧ and l ஥; seta v ஥ on trochanter shortest setae of leg. Leg II ( Fig. 5B ). Setal formula: Tr1–Fe3–Ge3–Ti4(1)–Ta6(1). Tarsus with setae tc ஧ and u ஥ smooth and subequal, other setae of segment barbed, solenidion ω 8 (7–8) digitiform; all setae on tibia barbed except smooth d, setae d shorter than other tibial setae, solenidion φ 4 (3–4) digitiform; genu with setae v ஥ barbed and longer than setae

l ஧ and l ஥; all setae on femur smooth, setae l ஥ and v ஧ subequal and distinctly shorter than seta

d; seta v ஥ on trochanter barbed and longer than v ஥ of genu. Leg III ( Fig. 6A ). Setal formula: Tr1–Fe2–Ge2–Ti4(1)–Ta6. All setae on tarsus smooth except barbed pv ஥; all setae on tibia subequal and barbed except smooth d, solenidion φ 3 (3–4) weakly clavate; genu with setae

v ஥ and l ஥ subequal, seta v ஥ barbed; seta v ஥ on femur barbed and subequal with smooth v ஥; trochanter with seta v ஥ smooth and longer than v ஥ on femur. Leg IV ( Fig. 6B ). Setal formula: Tr1–Fe2–Ge1–Ti3–Ta6. Longer than other legs. Tarsus with setae u ஥, pv ஥ and tc ஥ barbed, seta

pl ஧ shortest and tc ஥ longest setae of segment; all setae on tibia barbed except smooth l ஥, seta d longest on segment; pore-like structure visible below base of seta d; genu with seta v ஥ barbed; femur with seta d more than twice longer than v ஥, both barbed; seta v ஥ on trochanter smooth and slightly longer than femoral seta v ஥.

Male and larva. Unknown.

Differential diagnosis — The new species can be distinguished from N. sibiriensis by the absence of setae 4 a (present in N. sibiriensis ). Also N. lucani sp. nov. differs from N. iranicus by seta cha and m subequal (seta cha two times longer than m in N. iranicus ), seta e and h 2 subequal (seta e more than 1.5 times longer than h 2 in N. iranicus ), setae ps 1 and ps 3 subequal and two times longer than ps 2 (setae ps 1-3 subequal in N. iranicus ).

Type material — Female holotype (VRSS-20190705-8) and three female paratypes, in the vial containing Lucanus ibericus Motschulsky, 1845 (Col.: Lucanidae ). The hosts captured by a light trap from Alangdareh forest, with Hornbeam trees Carpinus (spp.) and Oak trees ( Quercus spp. ), Gorgan town, Golestan province, northern Iran, 36.46°N, 54.26°E, altitude,

408 m., coll. V. Rahiminejad, 5 July 2019.

Etymology — The name of the new species refers to generic name of the host beetle, Lucanus .

Remark — This is the first record of association between Neomicrodispus mites and lucanid beetles. Previously, N. iranicus was found in a vial containing beetle Oryctes nasicornis (L.)

(Col.: Scarabaeidae ) in northern Iran and N. sibiriensis collected from a decaying tree stump in Western Siberia, Russia.

Figures

Figure 4 Neomicrodispus lucanisp. nov., female. A – body in dorsal view, B – body in ventral view, C – Pharyngeal system.

Figure 5 Neomicrodispus lucani sp. nov., female. A – leg I, B – leg II.

Figure 6 Neomicrodispus lucani sp. nov., female. A – leg III, B – leg IV.