Adactylidium europaeum, Khaustov & Abramov, 2021

Khaustov, Alexander A. & Abramov, Vladimir V., 2021, A new species of Adactylidium (Acari: Heterostigmata: Acarophenacidae) associated withPhlaeothrips sp. (Thysanoptera: Phlaeothripidae) from European Russia, Acarologia 61 (2), pp. 356-364 : 358-360

publication ID	https://doi.org/ 10.24349/acarologia/20214435
persistent identifier	https://treatment.plazi.org/id/03FD8793-3C07-FFF4-70F4-6FD9FBFA56D4
treatment provided by	Marcus
scientific name	Adactylidium europaeum
status	sp. nov.

Treatment

Adactylidium europaeum n. sp.

Zoobank: 227447D6-8908-4C9C-8555-E92E102DC85A

( Figures 1–6 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 )

Diagnosis — Apgn with median projections; genua I and III with three and one setae, respectively; tibiotarsus I with ventral subapical indentation; setae (tc) and (ft) of tibiotarsus I subequal in length; dorsal idiosomal setae with similar shape, elongate; apsej not fused with appr; setae 1 b absent.

Description

Female – Length of idiosoma 130 (130, 135), width 100 (98, 105).

Gnathosoma ‒ Apgn with distinct median projections ( Fig. 6 A View Figure 6 ). Gnathosoma concealed dorsally by prodorsum, ventrally indistinguishable from idiosoma; dorsum with one pair of setae anterolaterally, probably representing postpalpal seta pp ; venter with mouth flanked by paired, semi-ovular smooth membranous areas; one pair of rod-like ventral setae of unknown homology situated at anterior ends of membranous areas; one pair of blunt-ended subcapitular setae m located posteriad membranous areas. Pharynx large, slightly oval, thin walled, distinctly punctate ( Fig. 6B View Figure 6 ).

Idiosomal dorsum ( Figs 1A View Figure 1 , 4A View Figure 4 , 5A View Figure 5 ) ‒ Ovate. Prodorsal shield delineated into primary plate and prodorsal projection, encapsulating gnathosoma. Stigmata on prodorsal projection; tracheal trunks long, with small atria located posteriad posterior margin of apgn. Prodorsal shield and plates C, D, EF, H distinctly punctate ( Fig. 5A View Figure 5 ). Alveolar pits sc 1 situated anterolaterad bases of setae v 2. Setae v 2, sc 2, c 1 and c 2 thin, smooth and pointed; setae d, e and f with few weak barbs in basal half; setae h 1 and h 2 located ventrally, slightly thickened, blunt-ended and weakly barbed. Cupuli ia small, round, located laterad or anterolaterad bases of setae d ; cupuli im situated anteromesad bases of setae e ; cupuli ih not evident. Lengths of dorsal setae: v 2 38 (38, 43), sc 2 18 (18, 19), c 1 17 (18), c 2 17 (18), d 17 (18, 20), e 15 (17, 18), f 17 (18), h 1 7 (8, 9),

h 2 6 (7, 8). Distances between setae: v 2 –v 2 34 (34, 38), sc 1 –sc 1 43 (42, 47), v 2 –sc 2 17 (16–18), sc 2 –sc 2 66 (65, 71), c 1 – c 1 43 (42, 45), c 1 – c 2 22 (23, 24), d–d 52 (49, 58), e–f 16 (15, 16), f –f

20 (19, 26), e–e 52 (48, 52), h 1 – h 1 13 (11), h 2 – h 2 8 (11, 12).

Idiosomal venter ( Figs 1B View Figure 1 , 4B View Figure 4 , 5B View Figure 5 ) ‒ Ventral plates smooth; small subtriangular areas posteriad trochanters II with rough microsculpture; coxisternal fields IV with weak longitudinal striation ( Fig. 5B View Figure 5 ). All ventral setae smooth and pointed; setae 1 b absent. Aggenital plate with deep incision posteriorly. Ap1 weakly sclerotized, fused with well sclerotized appr; ap2 well sclerotized and fused with appr; apsej well sclerotized, not fused with appr; ap3 well developed, fused with well-developed appo; ap4 well sclerotized, not fused with appo; ap5 absent. Lengths of ventral setae: 2 a 11 (12–13), 3 a 11 (12, 13), 3 c 11 (12), 4 b 276 (7, 8), 4 c 9 (8, 10), ag 7 (7,

8).

Legs ( Figs 2 View Figure 2 , 3 View Figure 3 ) ‒ Leg I ( Fig. 2A View Figure 2 ) distinctly shorter than other legs. Leg setation: Tr 0, Fe 3, Ge 3, TiTa 15(1). Tibiotarsus with ventral subapical indentation. Solenidion ω 4 (3, 4) clavate, situated in the middle of segment. Seta k bifurcate; eupathidia tc () and (ft) subequal in length. At least setae l”, v” and pv” of tibiotarsus weakly barbed, other leg setae smooth; setae d, l′ of femur and eupathidia (tc) and (ft) blunt-ended, other leg setae pointed. Leg II ( Fig. 2B View Figure 2 ). Leg setation: Tr 0, Fe 3, Ge 3, Ti 4, Ta 6(1). Solenidion ω 4 (4, 5) digitiform. Setae l′ of femur and (u) of tarsus blunt-ended, other leg setae pointed; at least setae l′ of tibia and (pv) of tarsus weakly barbed, other leg setae smooth. Leg III ( Fig. 3A View Figure 3 ). Leg setation: Tr 0, Fe 2, Ge 1, Ti 4, Ta 4. Setae (u) of tarsus blunt-ended, other leg setae pointed; at least setae v′ of femur,

v′ of genu, l′, v” of tibia and pv′ of tarsus weakly barbed, other leg setae smooth. Leg IV ( Fig. 3B View Figure 3 ). Leg setation: Tr 0, Fe 1, Ge 1, Ti 4, Ta 4. Setae (u) of tarsus blunt-ended, other leg setae pointed; at least setae v′ of genu, l′, v” of tibia weakly barbed, other leg setae smooth; seta tc” of tarsus ultralong.

Type material — Female holotype, slide ZISP T-Acaroph-001, Tula Region, vicinity of Suvorov town, 54°07 ′ N, 36°30 ′ E, 10 November 2020, on thorax of larva of Phlaeothrips sp. on the bark of thin dead branches of birch, coll. V.A. Abramov. Paratypes: two females, same data, 14 November 2020.

Type deposition — The holotypes of the new species is deposited in the acarological collection of the Zoological Institute of RAS, St. Petersburg, Russia ; two female paratypes are deposited in the mite collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.

Etymology — The name of the new species refers to distribution in European part of Russia.

Differential diagnosis — The new species is most similar to Adactylidium ficorum Goldarazena and Ochoa, 2001 , described from Puerto Rico and Egypt ( Goldarazena et al. 2001) in having three setae on genu I, one seta on genu III, and well developed appo. The new species differs from A. ficorum in having apsej not fused with appr (apsej fused with appr in A. ficorum ), setae 1 b completely absent (alveoli of setae 1 b present in A. ficorum ) and median projections present on apgn (absent in A. ficorum ).