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.