Eustigmaeus collarti ( Cooreman, 1955 )

Khaustov, Alexander A. & Tolstikov, Andrei V., 2014, A new species and new records of the genus Eustigmaeus (Acari: Prostigmata: Stigmaeidae) from Western Siberia, Zootaxa 3861 (6), pp. 531-553 : 540-547

Eustigmaeus collarti ( Cooreman, 1955)

( Figs. 16–27 , 32–33)

Caligonus collarti Cooreman, 1955 , p. 163, figs. 1–5. Ledermuelleria collarti, Summers & Price 1961: 369 . Eustigmaeus collarti, Doğan 2006: 88 .

Redescription. FEMALE ( Figs. 16–22 , 32–33). Body weakly sclerotized. Idiosoma oval in outline. Length of idiosoma 290–305, width 220–230. Idiosomal dorsum ( Figs. 16 , 32). Dorsal plates with distinct polygonal ornamentation. Dorsal setae subequal, baculiform, with small barbs ( Figs. 16 , 33). Suranal plate dorsal. Diameter of eyes 8–9. Length of dorsal setae: vi 45 –51, ve 46–49, sci 36–38, sce 38–41, c 1 40–44, c 2 41–44, d 1 41–43, d 2 39–41, e 1 42 –44, e 2 40 –43, f 1 50–52, h 1 42–45, h 2 37–40. Distances between setae: vi– vi 16–21, ve–ve 61–63, sci–sci 105–110, sce–sce 146–152, c 1– c 1 72–79, d 1– d 1 72–80, d 2– d 2 170–178, e 1– e 1 56 –59, e 2– e 2 129–131, f 1– f 1 58–67. Idiosomal venter ( Fig. 17 ). Сallosities absent. Endopodal plates separated medially, distinctly reticulated. Humeral plate triangular, reticulated. Aggenital plate distinctly reticulated. With 2 pairs of simple aggenital, and 3 pairs of simple subequal pseudanal setae. Length of ventral setae: 1 a 24–25, 1 b 24–27, 1 c 24–26, 2 b 25–27, 2 c 24–25, 3 a 23–27, 3 b 22–25, 3 c 20–24, 4 a 22–26, 4 b 23–27, 4 c 24–26, ag 1 24–25, ag 2 18–23, ps 1 19–21, ps 2 20–21, ps 3 20–22. Gnathosoma ( Fig. 18 ). Tibial claw large. Setae l’ on palpal tibia spine-like. Setae on palpal femur and genu barbed, other palpal setae smooth. Number of setae on palpal segments as in E. tjumeniensis sp. nov. Palpal supracoxal setae peg-like. Rostrum of subcapitulum distinctly longer than its width. Subcapitular setae smooth, pointed. Basal part of subcapitulum without distinct reticulation. Length of subcapitular setae: m 22–25, n 22–27, or 1 13–14, or 2 18–19. Legs ( Figs. 19–22 ). All legs with a pair of well-developed claws. Empodial raylets pointed. Leg chaetotaxy as in E. tjumeniensis sp. nov., except presence of 2 setae (v’, l’) on trochanter III. Leg I ( Fig. 19 ). Coxae I posterodorsally with peg-like leg supracoxal setae (elcl). Setae d on femur blunt-ended. Seta k unusually long 30–35. Solenidion ω relatively short 13–14, finger-shaped; solenidion φ 8 baculiform, φp attenuate 25–26. Leg II ( Fig. 20 ). Without distinctly modified setae. Solenidion ω 13–14 finger-shaped; solenidion φ 21–23 attenuate. Seta k 6–7. Leg III ( Fig. 21 ). Solenidion ω 5 baculiform; solenidion φ 17–19 attenuate. Leg IV ( Fig. 22 ). Solenidion ω 4 baculiform; solenidion φ 22–23 attenuate.

MALE ( Figs. 23–27 ). Length of idiosoma 285, width 180. Idiosomal dorsum. Dorsal idiosomal plates distinctly reticulated. Dorsal setae as in female. Plates CD and EF separated. Diameter of eyes 8. Length of dorsal setae: vi 37, ve 36, sci 32, sce 34, c 1 33, c 2 38, d 1 34, d 2 33, e 1 35, e 2 33, f 1 41, h 1 23, h 2 32, ps 1 9, ps 2 5, ps 3 5. Distances between setae: vi– vi 13, ve–ve 54, sci–sci 92, sce–sce 124, c 1– c 1 66, d 1– d 1 54, d 2– d 2 121, e 1– e 1 45, e 2– e 2 84, f 1– f 1 50. Penis large, well sclerotized, divided into two parts ( Fig. 23 ). Idiosomal venter. Podosoma similar with that of female. With 2 pairs of simple subequal aggenital setae. Length of ventral setae: 1 a 21, 1 b 20, 1 c 18, 2 b 18, 2 c 19, 3 a 23, 3 b 20, 3 c 20, 4 a 23, 4 b 22, 4 c 22, ag 1 19, ag 2 18. Gnathosoma as in female. Length of subcapitular setae: m 20, n 16, or 1 12, or 2 18. Legs ( Figs. 24–27 ). Similar with those in females but tarsi I–IV with additional large finger-shaped male solenidion (ω ♂). Length of solenidia and setae k on legs I–IV: I— ω 16, ω ♂43, φ 8, φp 26, k 32; II— ω 13, ω ♂40, φ 20, k 5; III— ω 5, ω ♂35, φ 20; IV— ω 4, ω ♂44, φ 25.

Material examined. Ten females, RUSSIA: Tyumen Province, vicinities of lake Kuchak, 57 0 21’N, 66 0 03’E, from mosses Sphagnum sp. in fen along lakeshore where seasonal changes in water level maintain wet soils, 31 May 2014, coll. A.V. Tolstikov; 4 females, 1 male, from same locality, 30 June 2014, coll. V.A. Stolbov.

FIGURES 28–33. SEM photos: Eustigmaeus tjumeniensis Khaustov and Tolstikov sp. nov., female: 28—dorsum of the body, 29—prodorsum, 30—setae vi, 31—setae e 1; Eustigmaeus collarti ( Cooreman, 1955) , female: 32—dorsum of the body, 33—setae f 1.

Remarks. This hygrophilous species was described from mosses in France ( Cooreman 1955). It was also recorded and redescribed from Turkey ( Doğan 2006). This is the first record from Russia.

Specimens from Russia are well agreeing to the original description of Cooreman (1955) and redescription of Doğan (Doğan 2006). The only difference in that seta k on genu I of specimens from Russia distinctly longer (30–35) than in specimens from Turkey (20). But it could be a result of geographical variability of this species.

Figures

FIGURE 18. Eustigmaeus collarti (Cooreman, 1955), female: — gnathosoma dorsally.

FIGURES 23. Eustigmaeus collarti (Cooreman, 1955), male: — posterior part of hysterosoma dorsally.

FIGURES 24 – 25. Eustigmaeus collarti (Cooreman, 1955), male: 24 — leg I, 25 — leg II.

FIGURES 26 – 27. Eustigmaeus collarti (Cooreman, 1955), male: 26 – leg III, leg IV.

FIGURES 16 – 17. Eustigmaeus collarti (Cooreman, 1955), female: 16 — idiosomal dorsum, 17 — idiosomal venter.

FIGURES 19 – 20. Eustigmaeus collarti (Cooreman, 1955), female: 19 — leg I, 20 — leg II.

FIGURES 21 – 22. Eustigmaeus collarti (Cooreman, 1955), female: 20 — leg III, 21 — leg IV.