Agistemus macrosetosus Stathakis & Kapaxidi

Stathakis, Theodoros I., Kapaxidi, Eleftheria V. & Papadoulis, Georgios Th., 2014, A new record and a new species of the genus Agistemus Summers (Acari: Stigmaeidae) from Greece, Zootaxa 3780 (1), pp. 153-170 : 162-168

Agistemus macrosetosus Stathakis & Kapaxidi n. sp.

Diagnosis. Female. Dorsal shields plain; pob about 3.4 times as large as eye; dorsal idiosomal setae long and barbed, tapered distally, set on tubercules; vi / vi–vi 4.8 4.6 (4.4–5.0), c1 / c1–c1 2.9 2.9 (2.1–3.0). Aggenital shield divided along midline by a striated area, each side with two subequal setae (ag1, ag2). Coxa IV with two setae; femur I with five setae; genu I with 3+1 κ; tibia IV with 5+1 φp; tarsus I with 12+1 ω; tarsus IV with seven setae. Male. Postocular body 2.6 times as large as eye; vi / vi–vi 3.8 3.0 (2.9–3.8), c1 / c1–c1 2.0 1.7 (1.4–2.0).). Aggenital shield entire, belt–shaped with two pairs of subequal setae (ag1, ag2). Dorsal shields and counts of setae and solenidia as in female except for tarsi I–IV with 12+2 ω, 9+2 ω, 7+1 ω, 7+1 ω.

Female (n = 7)

Dorsum ( Figure 23 ). Oval, sclerotized; length of body (excluding gnathosoma) 305 324 (301–361), width 226 249 (226–278). Idiosoma covered with seven plain shields surrounded by fine striae. Dorsal setae set on tubercles, long and barbed, with blunt tip, except for c2 which are more slender ( Figures 24 , 34 ). Prodorsal shield with three pairs of setae, vi 58 64 (58–72), ve 90 97 (90–105), sci 76 85 (76–96), one pair of eyes 10 11 (10–12) in diameter and one pair of postocular bodies (pob) 34 37 (32–40) in diameter. Central hysterosomal shield entire, rounded, bearing five pairs of setae, c1 80 85 (80–90), d1 80 86 (80–96), d2 82 88 (80–99), e1 90 98 (90–109), e2 92 98 (92– 109). Intercalary shields with setae f1 70 80 (70–88). Humeral shields with setae c2 42 51 (40–60) ( Figures 25 , 35 ). Suranal shield with two pairs of setae h1 42 48 (42–52) and h 2 24 30 (24–34).Distances between setae: vi– vi 12 14 (12–16), ve–ve 50 52 (50–54), sci–sci 105 106 (99–111), vi–ve 26 27 (24–34), ve–sci 40 44 (40–48), c1–c 1 28 33 (28–42), d1–d1 88 88 (80–99), d2–d2 123 131 (123–139), e1– e1 34 34 (30–36), e2–e2 113 122 (113–133), f1–f1 62 67 (60–74), h1–h 1 20 17 (14–20), h2–h2 58 60 (54–66), c1–d1 58 62 (58–66), c1–d2 60 64 (60–70), d1–d 2 30 29 (26–36), d1– e1 60 66 (58–72), d1– e2 44 44 (40–48), d2– e2 58 57 (54–60), e1– e2 44 49 (44–54), e1–f1 34 34 (26– 40), h1–h 2 22 26 (22–28). Ratios: pob /eye 3.4 3.4 (3.0–4.0), vi / vi–vi 4.8 4.6 (4.4–5.0), c1 / c1–c1 2.9 2.9 (2.1–3.0), d1 / d1–d1 0.9 1.0 (0.9–1.0), e1 / e1– e1 2.6 2.9 (2.6–3.0), h1 / h2 1.8 1.6 (1.6–1.8).

Venter ( Figure 26 ). Ventral setae subequal, 1a 35 37 (29–47), 3a 31 38 (31–47), 4a 35 40 (33–47). Aggenital shield divided along midline by a striated area, each side with two subequal setae, ag 1 16 18 (16–21) and ag 2 16 19 (16–21). Anogenital covers with one pair of genital setae, g 1 18 19 (17–20) and three pairs of pseudanal setae, ps 1 14 16 (14–19), ps 2 17 17 (16–18), ps 3 15 16 (15–19) ( Figure 27 ).

Gnathosoma. Subcapitulum bearing two pairs of adoral setae (ro1, ro2) and two pairs of subcapitular setae, m 31 35 (31–39) and n 51 52 (48–55). Distances between subcapitular setae: m–m 41 43 (41–47), n– n 31 33 (31–35) and m– n 8 10 (8–11) ( Figure 28 ). Movable cheliceral digits 40 41 (40–44), in length. Palpi five-segmented; palptarsus with a tridentate terminal eupathidium, one subterminal spine-like eupathidium, one solenidion and four smooth setae; palptibia with a large claw, a robust accessory claw and two proximal setae; palpgenu with one smooth seta; palpfemur with two smooth and one barbed setae ( Figure 29 ).

Legs ( Figures 30–33 ). Length of legs: legI 294 301 (290–321), legII 254 260 (242–286), legIII 246 257 (238– 278), legIV 274 297 (274–317). Counts of setae and solenidia on legs I–IV: coxae 2+1 elcp, 1, 2, 2; trochanters 1, 1, 1, 1; femora 5, 4, 2, 2; genua 3+1 κ, 1, 0, 0; tibiae 5+1 φp, 5+1 φp, 5+1 φp, 5+1 φp; tarsi 12+1 ω, 9+1 ω, 7+1 ω, 7. Length of spines and solenidia: κ I 3 3 (3–4), ω I 26 28 (26–31), ω II 27 27 (26–29), ω III 17 18 (16–20).

Male (n = 5)

Dorsum ( Figure 36 ). Oval, well sclerotized; length of body (excluding gnathosoma) 266 252 (238–274), width 191 190 (179–202). Idiosoma covered with five shields surrounded by fine striae. Dorsal setae as in female. Prodorsal shield with three pairs of setae, vi 60 52 (50–60), ve 74 66 (60–74), sci 70 62 (56–70), one pair of eyes 10 11 (10–14) in diameter and one pair of postocular bodies (pob) 30 28 (24–30) in diameter. Central hysterosomal shield entire, bearing six pairs of setae, c1 60 55 (50–60), d1 40 40 (34–46), d2 62 59 (54–62), e 1 28 27 (26–28), e2 64 60 (54–68), f1 66 61 (56–66). Humeral shields with setae c2 50 44 (40–50). Suranal shield with two pairs of setae h 1 14 16 (14–18) and h 2 20 20 (18–20). Distances between setae: vi– vi 16 17 (16–18), ve–ve 52 49 (46–52), sci–sci 92 95 (92–99), vi–ve 24 22 (20–24), ve–sci 36 39 (36–42), c1–c 1 30 33 (30–36), d1–d1 76 73 (68–78), d2– d2 111 111 (103–115), e1– e1 34 34 (32–36), e2– e2 94 94 (84–103), f1–f1 42 41 (38–44), h1–h 1 12 10 (6–12), h2– h2 40 44 (40–48), c1–d1 50 53 (50–56), c1–d2 54 54 (50–58), d1–d 2 20 24 (20–28), d1– e1 44 44 (42–46), d1– e 2 30 30 (28–30), d2– e2 38 41 (38–44), e1– e2 34 33 (30–36), e1–f 1 20 20 (16–24), h1–h 2 16 18 (14–20). Ratios: pob / eye 3.0 2.6 (2.1–3.0), vi / vi–vi 3.8 3.0 (2.9–3.8), c1 / c1–c1 2.0 1.7 (1.4–2.0), d1 / d1–d1 0.5 0.5 (0.5–0.7), e1 / e1– e1 0.8 0.8 (0.7–0.8), h1 / h2 0.7 0.8 (0.7–0.9).

Venter ( Figure 37 ). Ventral setae subequal, 1a 35 35, 3a 31 33 (31–35), 4a 35 32 (31–35). Aggenital shield entire, belt–shaped with two pairs of subequal setae, ag 1 20 18 (16–20) and ag 2 18 17 (14–18). Anal area with three pairs of pseudanal setae, ps1 5 6 (5–6), ps 2 12 12 (11–12), ps 3 16 13 (9–16) ( Figure 38 ). Aedeagus as in Figure 39 .

Gnathosoma. Subcapitulum bearing two pairs of adoral setae (ro1, ro2) and two pairs of subcapitular setae, m 31 31 (30–31) and n 43 45 (43–47). Distances between subcapitular setae: m–m 42 41 (39–44), n– n 31 31 (29–32) and m– n 8 9 (8–9) ( Figure 40 ). Movable cheliceral digits 40 36 (34–40), in length. Palpi five-segmented; palptarsus with a tridentate terminal eupathidium, one subterminal spine-like eupathidium, one solenidion and four smooth setae; palptibia with a large claw, a robust accessory claw and two proximal setae; palpgenu with one smooth seta; palpfemur with two smooth and one barbed setae ( Figure 41 ).

Legs ( Figures 42–45 ). Length of legs: legI 290 284 (270–290), legII 246 238 (222–246), legIII 238 236 (222– 242), legIV 266 260 (250–266). Counts of setae and solenidia on legs I–IV: coxae 2+1 elcp, 1, 2, 2; trochanters 1, 1, 1, 1; femora 5, 4, 2, 2; genua 3+1 κ, 1, 0, 0; tibiae 5+1 φp, 5+1 φp, 5+1 φp, 5+1 φp; tarsi 12+2 ω, 9+2 ω, 7+1 ω, 7+1 ω. Length of spines and solenidia: κ I 4 4, ω I 29 26 (23–29), ω I♂ 34 34 (31–37), ω II 26 26 (25–27), ω II♂ 32 32 (28– 34), ω III 16 16 (14–17), ω IV 17 18 (14–20).

Type material. Holotype female collected at Kaiafas Lake, Co. Elia, on Rubus sp. ( Rosaceae ), 11 June 2011. One female paratype collected at Kaiafas Lake, Co. Elia, on Rubus sp. ( Rosaceae ), 27 October 2012. The allotype male, four male and five female paratypes collected at Lefkochora, Co. Messinia, on Rubus sp. ( Rosaceae ), 17 March 2013.

The holotype female, allotype male, six female and five male paratypes are deposited in the Acari collection of Laboratory of Agricultural Zoology and Entomology, Agricultural University of Athens, Greece. One female paratype will be deposited in the Natural History Museum, London (NHM).

Etymology. The name of this new species is derived from its very long dorsal setae (macro =long + setosus).

Remarks. This new species has the same leg chaetotaxy as Agistemus takagii Ehara , Agistemus longisetus Gonzales-Rodriguez and Agistemus riograndensis Johann & Ferla. It resembles A. takagii in havingthe aggenital shield divided along its midline, with two subequal aggenital setae, but differs from it by having most dorsal setae longer and the ratio vi / vi–vi 4.8 4.6 (4.4–5.0) instead of 1.1 in the latter. It resembles A. longisetus in having equal lengths of most dorsal setae and ratio pob /eye but it differs from it by having vi / vi–vi 4.8 4.6 (4.4–5.0) instead of 2.6–2.7 in the latter. It also resembles A. riograndensis in having equal lengths of most dorsal setae and ratio vi / vi– vi but differs from it by having the aggenital shield divided along its midline instead of an entire horseshoe-shaped aggenital shield in A. riograndensis . Moreover, the postocular body of A. riograndensis is about twice as long as the eye in diameter, while in A. macrosetosus n. sp., the postocular body is 3.4 times the diameter of eye.

Figures

FIGURES 23 – 29. Agistemus macrosetosus Stathakis & Kapaxidi n. sp. (female). 23. Dorsum; 24. Seta ve; 25. Seta c 2; 26. Venter; 27. Anogenital region (ventral view); 28. Subcapitulum; 29. Palp. Scale bar = 100 Μm for 23, 26; 30 Μm for 24, 25, 27, 28, 29.

FIGURES 34 – 35. Agistemus macrosetosus Stathakis & Kapaxidi n. sp. (female). 34. Seta e 2; 35. Seta c 2. Scale bar = 30 Μm.

FIGURES 30 – 33. Agistemus macrosetosus Stathakis & Kapaxidi n. sp. (female). 30. Leg I; 31. Leg II; 32. Leg III; 33. Leg IV. Scale bar = 100 Μm.

FIGURES 36 – 41. Agistemus macrosetosus Stathakis & Kapaxidi n. sp. (male). 36. Dorsum; 37. Venter; 38. Anal region (dorsal view); 39. Aedeagus; 40. Subcapitulum; 41. Palp. Scale bar = 100 Μm for 36, 37; 30 Μm for 38, 39, 40, 41.

FIGURES 42 – 45. Agistemus macrosetosus Stathakis & Kapaxidi n. sp. (male). 42. Leg I; 43. Leg II; 44. Leg III; 45. Leg IV. Scale bar = 100 Μm.