Lebertia (Pilolebertia) saxonica Thor, 1911

Tuzovskij, Petr V., 2016, Larval morphology of Lebertia insignis Neuman, 1880, L. porosa Thor, 1900 and L. saxonica Thor, 1911 (Acari, Hydrachnidia: Lebertiidae), Zootaxa 4121 (3), pp. 295-310 : 303-309

Lebertia (Pilolebertia) saxonica Thor, 1911

( Figs 26–39 )

Material examined. Larvae (n = 38) were reared from six females: one female collected in a could brook near the village Postyltsevo (August 2000) and one female in the Ild stream near village Mar’ino (August 2006), Nekouz District, Yaroslavl Province; four females from the Pucheveem stream (inflow of the Chaun river) Chaun District, Magadan Province (August-September 1982). The duration of the embryonic period was 12–15 days.

Diagnosis. Larva. Dorsal plate elongated (L/W ratio 1.5–1.8); excretory pore plate oval; P-4 short (L <H); urstigma small (D 9–11 µm); I–III-Leg–5 comparatively long (78–90, 89–106, 102–128 µm, respectively); III– Leg-5 without acanthoid seta. Adult. P-3 mediodistal seta close to the ventrodistal seta ( Fig. 39 ).

Redescription. Larva. Dorsal plate elongate (L/W ratio 1.5–1.8) ( Fig. 26 ), its anterior margin slightly convex with small median incision, posterior margin pointed. Nine pairs of long setae (Oe, Hi, He, Sci, Sce, Li, Le, Si, Se) situated in the soft wrinkled membrane: Li, Le, Si and Se shorter than Hi, He, Sci, Sce and Oe. Urstigma small.

Excretory pore plate oval or nearly circular, with short anteriomedian projection ( Figs 28–29 ).

Pedipalps ( Fig. 32 ): P–2 with single dorsal seta in proximal part; P–4 short, its length smaller than height, with three short subequal setae (two dorsal and one medial); P–5 with two of the seven setae very long; solenidion shorter than segment.

Shape and arrangement of setae on legs segments as shown in Figs 33–35 . Number of heavy setae from trochanter to tarsus: I–Leg: 0, 1, 1, 1, 0; II–Leg: 0, 2, 2, 1, 0; III–Leg: 0, 1, 1, 1, 0. Solenidion on tibia III situated near middle of segment. Acanthoid setae present on I–II-Leg-5 only, all bent two times.

Measurements, n=10. Dorsal plate L 260–295, W 145–195; setae Fch L 64–96, setae Fp and Oi L 26–35, setae Vi L 135–175, setae Oe, Hi, He, Sci and Sce L 125–145; setae Li and Le L 100–135; setae Si and Se L 95–130, setae Ci L 145–195, setae Pi L 50–80, setae Pe L 60–120, setae C1 L 75–95, setae C2 L 85–135, setae C3 L 110–145, setae C4 L 110–160; coxal field L 245–320; medial margin of coxae I L 83–96, medial margins of coxae II–III L 105–117; ursrigma D 9–11; excretory pore plate L 35–42, W 32–40; capitulum L 86–103; basal segment of chelicera L 73–93, chela L 16–23; pedipalpal segments (P-1–5) L: 12–16, 35–45, 30–35, 16–19, 11–13, P-4 H 20– 26; leg segments L: I–Leg-1–5: 38–45, 50–58, 53–61, 67–80, 78–90; II–Leg-1–5: 44–48, 50–55, 51–61, 73–96, 89–106; III–Leg-1–5: 5 4–64, 54–61, 54–64, 76–99, 102–128.

Adult. Both sexes. Coxal shield wider than long ( Fig. 38 ); W posteromedial margin of Cx-II 25–45; P-3 mediodistal seta near ventrodistal seta ( Fig. 39 ); II–IV-Leg swimming setae numbers: 6–8 on II-Leg-5, 6–10 on III- Leg-4, 8–15 on III-Leg-5, 6–12 on IV-Leg-4, 9–15 on IV-Leg-5. IV-Leg-6 with 1–5 thin pointed and 3–6 thick, short with obtuse tips spine-like setae.

Female. Genital flaps L/W ratio 2.0–2.2.

Measurements, n=5. Idiosoma L 960–1700; seta Fch L 110–120; coxal shield L 680–850, W 750–825; Cx-I medial L 185–225, Cx-II medial L 140–190; capitular bay L 190–215, genital bay L 150–200; genital flaps L 190–265, W 85–100; genital acetabula (ac.1–3) L: 48–78, 50–73, 30–54; basal segment of chelicera L 24 0–300, chela L 40–45; pedipalpal segments (P-1–5) L: 30–45, 115–155, 90–125, 125–180, 30–35; leg segments L: I–Leg-1– 6: 85–90, 100–125, 115–140, 160–225, 180–225, 160–215; II-Leg-1–6: 75–95, 110–140, 125–175, 215–290, 225– 315, 205–290; III–Leg-1–6: 85–100, 150–215, 160–210, 250–325, 310–375, 250–325; IV–Leg-1–6: 130–175, 150– 215, 200–265, 285–375, 310–390, 260–365.

Male. Genital flaps elongate (L/W ratio 2.0–2.57), with 28–35 median setae and 5–8 lateral ones (Fig. 41).

Measurements, n=3. Idiosoma L 930–1125; seta Fch L 105–115; coxal shield L 610–890, W 700–875; Cx-I medial L 150–375, Cx-II medial L 110–165; capitular bay L 160–250, genital bay L 190–225; genital flaps L 160–225, W 75–100; genital acetabula (ac.1–3) L: 42–72, 40–66, 27–50; basal segment of chelicera L 18 0–295, chela L 30–42; pedipalpal segments (P–1–5) L: 30–42, 95–150, 78–125, 120–175, 27–42; leg segments L: I–Leg-1–6: 60–100, 80–125, 90–165, 125–225, 135–240, 100–200; II–Leg-1–6: 75–100, 90–150, 105–175, 160–275, 225–325, 180–290; III–Leg-1–6: 75–115, 1 25–175, 35–225, 210–350, 250–400, 225–350; IV–Leg-1–6: 160–190, 175–190, 235–275, 325–370, 375–390, 310–365.

Remarks. The Asian larvae and adults of Lebertia saxonica are larger than European specimens and are characterized by the maximum values in the measurements.

Distribution in Russia. European part of Russia: Leningrad Province ( Sokolow 1940), Yaroslavl Province, Samara Province; Asian part of Russia: Kamchatka ( Thor 1926), Magadan Province and Chukotka.

Figures

FIGURES 26 – 27. Lebertia saxonica Thor, 1911, larva: 26, dorsal view; 27, ventral view. Scale bar: 50 µm.

FIGURES 28 – 32. Lebertia saxonica Thor, 1911, larva: 28 – 29, excretory pore plate; 30, chelicerae, dorsal view; 31, chela; 32, pedipalp. Scale bars: 28 – 29 = 50 µm, 30 – 32 = 20 µm.

FIGURES 33 – 36. Lebertia saxonica Thor, 1911, larva: 33, leg I; 34, leg II; 35, leg III; 36, claws of leg I. Scale bars: 33 – 35 = 50 µm, 36 = 20 µm.

FIGURES 37 – 39. Lebertia saxonica Thor, 1911, female: 37, seta Fch; 38, coxal field; 39, pedipalp. Scale bars: 37, 39 = 50 µm, 38 = 200 µm.