Sevastianoviella taurica, Khaustov & Khaustov, 2022

Khaustov, Alexander A. & Khaustov, Vladimir A., 2022, A new species of Sevastianoviella (Acari: Heterostigmata: Pygmephoridae) from Crimea, Persian Journal of Acarology 11 (3), pp. 457-470 : 458-465

Sevastianoviella taurica sp. nov. ( Figs. 1–9 )

http://zoobank.org/ urn:lsid:zoobank.org:act:F75C12EB-016E-4B79-BF23-AE89CF83812B

Description

Female ( Figs. 1–4 ) – Length of idiosoma 235 (215–235), width 110 (105–115).

Gnathosoma ( Fig. 2 ) – Gnathosomal capsule length 24 (23–25) subequal to its width 23 (23– 25); dorsally with two pairs of cheliceral setae (cha, chb). Setae cha weakly barbed and blunt-tipped; postpalpal setae (pp) smooth and blunt-tipped, situated posterolaterad setae cha, other gnathosomal setae smooth and pointed. Dorsal median apodeme absent. Venter of gnathosoma with a pair of setae m and a pair of small round pits n situated posteriad m. Palps with setae dFe and dGe dorsally; palp tibiotarsus with well-developed tibial claw and tiny peg-like seta distally; accessory setigenous structure club-shaped distally; palpal solenidion ω situated laterad accessory setigenous structure (ass). Pharyngeal pumps situated on long oesophagus; pump 1 bow-shaped with hardly discernible transverse striae, situated far posteriad gnathosoma and clearly separated from pumps 2 and 3; pharungeal pumps 2 and 3 contiguous, both ovate and transversely striate ( Fig. 2B ). Length of gnathosomal setae: cha 8 (7–8), chb 11 (10–11), pp 9 (9–11), dFe 8 (8), dGe 11 (10–11), m 12 (11– 12).

Idiosomal dorsum ( Fig. 1A ) – All dorsal shields with hardly discernible tiny puncta; stigmata long; setae sc1 club-shaped and with tiny barbs. All dorsal setae weakly barbed; setae sc2, c2, f, h1, and h2 long, pointed, whip-like; other dorsal setae distinctly shorter and blunt-tipped. All cupules ia on tergite D, im on tergite EF and ih on tergite H small, round. Prodorsal shield with short median apodeme in posterior part. Lengths of dorsal setae: v1 13 (12–14), v2 24 (22–26), sc2 66 (57–69), c1 16 (15–17), c2 64 (55–65), d 18 (14–18), e 10 (8–10), f 58 (48–58), h1 57 (45–57), h2 62 (54–63). Distances between setae: v1–v1 20 (20–21), v2–v2 27 (26–28), sc2–sc2 23 (23–26), c1–c1 39 (36– 39), c1–c2 26 (24–27), c2–c2 76 (70–80), d–d 41 (38–41), e–f 7 (7–8), f–f 52 (44–52), e–e 63 (57– 63), h1–h1 33 (28–33), h1–h2 7 (7).

Idiosomal venter ( Fig. 1B ) – All ventral plates with hardly discernible tiny puncta. Setae ps1-2 smooth, other ventral setae weakly barbed; setae 2a, 3a, 3b, 4a, and ps3 blunt-tipped, other ventral setae pointed; setae 1b characteristically not bifurcate; setae 4c absent. In two specimens (including holotype) one of setae 2a asymmetrically absent; in two specimens one of setae 4b asymmetrically absent. Apodemes ap1, ap2, ap3 and ap4 well developed; appr fused with ap2; apsej developed only laterally; appo fused with ap3 and ap4; ap5 absent. Posterior margin of aggenital plate evenly rounded. Lengths of ventral setae: 1a 15 (13–15), 1b 12 (11–12), 2a 19 (17–19), 2 b 7 (6–8), 3a 9 (7– 9), 3b 10 (9–10), 3c 14 (12–14), 4a 10 (9–10), 4b 15 (14–16), ps1 3 (3–4), ps2 3 (3), ps3 16 (14–16).

Legs ( Fig. 3 ) – Leg I ( Fig. 3A ). Leg setation: Tr 1 (v’), Fe 4 (d, l’, l”, v”), Ge 4 (l’, l”, v’, v”), Ti 6(2) (d, l’, l”, v’, v”, k, φ1, φ2), Ta 13(2) (p’ξ, p”ξ, tc’ ξ, tc” ξ, ft’, ft”, u’, u”, pl’, pl”, pv’, pv”, s, ω1, ω2). Tarsus with one simple claw. Solenidia ω1, ω2, and φ2 digitiform; solenidion φ1 clavate. Length of solenidia: ω1 7 (7), ω2 5 (5), φ1 6 (6–7), φ2 3 (3). Setae (p) and (tc) of tarsus eupathidlike; seta k of tibia smooth and blunt-tipped; setae (u) and (ft) smooth, other leg setae weakly barbed; setae v’ of trochanter and l’ of femur blunt-tipped, other setae pointed. Leg II ( Fig. 3B ). Leg setation: Tr 1 (v’), Fe 3 (d, l’, v”), Ge 3 (l’, l”, v’), Ti 4(1) (d, l’, v’, v”, φ), Ta 7(1) (tc’, tc”, u’, u”, pl”, pv’, pv”, ω). Tarsal claws simple, hooked; empodium short, flipper-like. Solenidion ω 5 (5–6) digitiform, solenidion φ 3 (3) peg-like. Setae tc” and (u) of tarsus smooth, other leg setae weakly barbed; setae v’ of trochanter and l’ of femur blunt-tipped, other leg setae pointed. Leg III ( Fig. 3C ). Leg setation: Tr 1 (v’), Fe 2 (d, v’), Ge 2 (l’, v’), Ti 4(1) (d, l’, v’, v”, φ), Ta 7 (tc’, tc”, pl”, u’, u”, pv’, pv”). Claws and empodium of same shape as on tarsus II. Solenidion φ 3 (3) peg-like. Setae tc” and (u) smooth, other leg setae weakly barbed; all leg setae pointed. Leg IV ( Fig. 3D ). Leg setation: Tr 1 (v’), Fe 2 (d, v’), Ge 1 (v’), Ti 4(1) (d, l’, v’, v”, φ), Ta 6 (tc’, tc”, pl”, u’, pv’, pv”). Claws and empodium of same shape as on tarsi II and III. Solenidion φ 2 (2) peg-like. Setae (tc) smooth, other setae weakly barbed; seta v” of tibia blunt-tipped, other setae pointed.

Male ( Figs. 4 , 5 ) – Length of idiosoma 160, width 95.

Gnathosoma – Gnathosomal capsule strongly reduced, with palps, cheliceral stylets and pharynx being absent; gnathosoma with three pairs of smooth and pointed setae: ventral m and subterminal dFe and dGe; accessory setigenous structure club-shaped distally; palpal solenidion ω situated laterad accessory setigenous structure.

Idiosomal dorsum ( Fig. 4A ) – All dorsal shields with hardly discernible tiny puncta. Setae d and h2 vestigial; setae h1 smooth, blunt-tipped and slightly widened distally; other dorsal setae weakly barbed; setae sc2, c2, and f long and pointed; other dorsal setae much shorter and blunt-tipped. Cupules ia on tergite CD, and im on tergite EF small, round; cupules ih not evident. Prodorsal shield with distinct median apodeme in posterior part; tergite CD with weak apodeme in central part. Lengths of dorsal setae: v1 9, v2 10, sc1 14, sc2 50, c1 14, c2 45, e 8, f 38, h1 5. Distances between setae: v1–v1 8, v2–v2 24, sc1–sc1 24, sc2–sc2 27, c1–c1 39, c1–c2 15, c2–c2 68, d–d 25, e–f 3, f– f 20, e–e 25, h1–h1 19, h2–h2 17.

Idiosomal venter ( Fig. 4B ) – All ventral plates with hardly discernible tiny puncta. Setae ps1 very short, spine-like; setae ps2 smooth and blunt-tipped, other ventral setae weakly barbed and blunttipped. Apodemes ap1, ap2, ap3, ap4 and ap5 well developed; appr fused with ap2; apsej absent; appo fused with ap4 and ap5. Aedeagus smooth, short and curved. Lengths of ventral setae: 1a 12, 1b 7, 2a 6, 2 b 7, 3a 7, 3b 9, 3c 8, 4a 6, 4b 7, ps1 2, ps2 7.

Legs ( Fig. 5 ) – Setation of legs as in female. Leg I ( Fig. 5A ). Tarsus with one simple claw. Solenidia ω1, ω2, and φ2 digitiform; solenidion φ1 clavate. Length of solenidia: ω1 5, ω2 3, φ1 6, φ2 3. Setae (p), (tc), and (ft) of tarsus eupathid-like; seta k of tibia smooth and blunt-tipped; setae l” of femur and (u) of tarsus smooth, other leg setae weakly barbed; setae v’ of trochanter and l’ of femur blunt-tipped, other leg setae pointed. Leg II ( Fig. 5B ). Tarsal claws simple, hooked; empodium short, flipper-like; solenidion ω 4 digitiform, solenidion φ 3 peg-like; setae (u) smooth, other setae weakly barbed; setae v’ of trochanter and l’ of femur blunt-tipped, other leg setae pointed. Leg III ( Fig. 5C ). Claws and empodium of same shape as on tarsus II; solenidion φ 3 peg-like. Setae (u) smooth, other setae weakly barbed; seta v’ of trochanter blunt-tipped, over leg setae pointed. Leg IV ( Fig. 5D ). Claws thick, empodium absent; solenidion φ 3 peg-like. Setae v’ of femur and genu, tc” and pv’ of tarsus barbed, other setae smooth; setae v’ of genu and tibia and tc” of tarsus pointed, other setae blunt-tipped; seta v” of tibia spine-like.

Larva ( Figs. 6 , 7 ). Length of idiosoma 175–180, width 105–110.

Gnathosoma – Gnathosomal capsule length 22–25 subequal to its width 23–25. Dorsally with two pairs of cheliceral setae (cha, chb). All gnathosomal setae smooth; setae cha and chb blunt-tipped, setae chb with widened distal part; other gnathosomal setae pointed; postpalpal setae and pits n absent. Dorsal median apodeme absent. Gnathosoma ventrally with one pair of setae m; palps with setae dFe and dGe dorsally; palp tibiotarsus with well-developed tibial claw and tiny peg-like seta distally; accessory setigenous structure club-shaped distally; palpal solenidion ω situated laterad accessory setigenous structure. Pharyngeal pumps as in female. Length of gnathosomal setae: cha 7, chb 4, dFe 7, dGe 9, m 10.

Idiosomal dorsum ( Fig. 6A ) – All dorsal shields smooth; all dorsal setae weakly barbed; setae sc2, c2, f, h1, and h2 long, whip-like and pointed; other dorsal setae distinctly shorter and blunttipped. Cupules ia on tergite D, ip on tergite EF and ih on tergite H small, round. Lengths of dorsal setae: v1 9, v2 9–10, sc1 20, sc2 68–70, c1 16–18, c2 53–58, d 28–29, e 15–18, f 58–62, h1 59–62, h2 45–70. Distances between setae: v1–v1 16, v2–v2 46–47, sc1–sc1 43–45, sc2–sc2 43–44, c1– c1 45–46, d–d 52–54, e–f 13–14, f–f 38–44, e–e 64–71, h1–h1 19–33), h1–h2 9–12.

Idiosomal venter ( Fig. 6B ) – All ventral plates smooth. Coxisternal plates I–II and III separated medially. Setae ps1 and ps3 smooth, pointed; other ventral setae weakly barbed and blunt-tipped. Only ap2 clearly visible. Lengths of ventral setae: 1a 9, 1b 5–7, 2a 7–9, 2 b 7–8, 3a 10–11, 3b 11, ps1 10–11, ps2 18–20, ps3 9–10.

Legs ( Fig. 7 ) – Leg I ( Fig. 7A ). Leg setation: Tr 0, Fe 4 (d, l’, l”, v”), Ge 4 (l’, l”, v’, v”), Ti 6(1) (d, l’, l”, v’, v”, k, φ1), Ta 11(1) (tc’ ξ, tc” ξ, ft’, ft”, u’, u”, pl’, pl”, pv’, pv”, s, ω1). Tarsus with two simple claws. Solenidion ω1 digitiform; solenidion φ1 clavate. Length of solenidia: ω1 5, φ1 5–6. Setae (tc) eupathid-like; setae l’ of femur and k of tibia smooth and blunt-tipped, other leg setae pointed; setae l”, v” of femur, l” of genu, d, v’ of tibia, (ft), (pl), (u) of tarsus smooth, other leg setae weakly barbed. Leg II ( Fig. 7B ). Leg setation as in female, except absence of seta v’ on trochanter. Tarsal claws and empodium as in female. Solenidion ω 4 digitiform, solenidion φ 3 peg-like. Setae l’, v” of femur, tc” and (u) of tarsus smooth, other leg setae weakly barbed; seta l’ of femur blunttipped, other leg setae pointed. Leg III ( Fig. 7C ). Leg setation: as in female, except absence of seta v’ on trochanter. Tarsal claws and empodium as in female. Solenidion φ 3 peg-like. Setae l’ of femur and (u) of tarsus smooth, other setae weakly barbed; seta l’ of femur blunt-tipped, other leg setae pointed.

Type material

Holotype female, slide ZISP T-Pygm-009, Crimea , vicinity of Yalta, 44° 29’ N 34° 05’ E, 560 m a.s.l., 6 April 2022, under the thin bark of a rotting linden ( Tilia sp. ) twig lying on the ground, coll. Khaustov V.A. paratypes: 5 females, 1 male, 10 larvae, same data.

Type deposition

The holotype female, four paratypes females and 5 larvae are deposited in the collection of ZIRAS ; other paratypes are deposited in the collection of the TSUMZ .

Differential diagnosis

Female of the new species is most similar to S. bohemicus , described from Czech Republic ( Mahunka 1967) in having subequal whip-like setae h1 and h2, setae 4b present, setae 4c absent and setae (ft) on tarsus I present; it can be distinguished from S. bohemicus in having simple setae 1b (setae 1b bifurcate in S. bohemicus ) and by distinctly shorter dorsal idiosomal setae c1 and d, which are considerably shorter than the distances between their bases (setae c1 and d distinctly longer than the distances between their bases in S. bohemicus ).

Etymology

The name of the new species is derived from Latin taurica meaning Crimea and refers to its geographical distribution.

Figures

Figure 1. Sevastianoviella taurica sp. nov. (female) – A. Dorsum of body; B. Venter of body. Legs omitted.

Figure 2. Sevastianoviella taurica sp. nov. (female) – A. Gnathosoma, dorsal aspect; B. Gnathosoma and pharyngeal pumps, ventral aspect.

Figure 3. Sevastianoviella taurica sp. nov. (female) – A. Right leg I, dorsal aspect; B. Right leg II, dorsal aspect; C. Right leg III, dorsal aspect; D. Right leg IV, dorsal aspect.

Figure 4. Sevastianoviella taurica sp. nov. (male) – A. Dorsum of body; B. Venter of body. Legs omitted.

Figure 5. Sevastianoviella taurica sp. nov. (male) – A–D. Right legs I–IV, respectively, dorsal aspect.

Figure 6. Sevastianoviella taurica sp. nov. (larva) – A. Dorsum of body; B. Venter of body. Legs omitted.

Figure 7. Sevastianoviella taurica sp. nov. (larva) – A–C. Right legs I–III, respectively, dorsal aspect.

Figure 8. Micrographs of Sevastianoviella taurica sp. nov. colony under removed thin bark of rotting linden twig – A. General view; B. Enlarged view of physogastric female with numerous developing eggs inside the body. Ph f – physogastric female, l – larva.

Figure 9. Micrographs of Sevastianoviella taurica sp. nov. colony under removed thin bark of rotting linden twig – A. General view; B. Enlarged view of physogastric and young females just started to feed. Ph f – physogastric female, y f – young female, l – larva.