Anadenosternum azaleense (Daele)

Fenďa, Peter, 2017, A revision of the genus Anadenosternum Athias-Henriot (Acari: Mesostigmata: Parasitidae), Zootaxa 4324 (3), pp. 436-450 : 442-448

Anadenosternum azaleense (Daele)

( Figures 17–45 )

Parasitus azaleensis Daele, 1975: 4 .

Anadenosternum azaleense .— Athias-Henriot, 1980: 287.

Anadenosternum azaleensis .— Karg & Glockemann, 1995: 462. Anadenosternum pediculosum Karg & Glockemann, 1995: 461 . New synonymy. Anadenosternum pediculosus (sic).— Karg & Glockemann, 1995: 462.

Diagnosis. In female, endogynium formed as a relatively large rounded sac, laterally with reticulated and punctated fields in the form of a drop; medially with variously formed process, the process slender and oblong, rod-like, penis-like, thorn-like, or widened, trapezoidal, sharply or obtusely pointed, or more often with bifurcate apex. Ventrianal shield with ten pairs of ventral setae. In male, genital lamella with anterolateral margins incised, expanded and produced into small wing-like structures directed laterally; fixed digit with bidentate hook and a row of 8–11 sharp denticles, some of these denticles often with two minute apices.

Redescription. FEMALE. Dorsal idiosoma ( Fig. 17 ). Length 430–485 µm, width 260–290 µm (n = 15). Dorsal shield divided into podonotal and opistonotal shields by a narrow transverse fissure; both shields finely reticulated, opisthonotal reticulation stronger; transverse lines of reticulation dominant. Podonotal shield 210–240 µm wide and 200–220 µm long, with 23 pairs of smooth, needle-like, uniform and medium length setae. The length of most podonotal setae 30–42 µm, vertical setae j 1 30–32 µm long, only setae z1, s1, s2, r2 and r4 shorter (z 1 16–19, s1 26, s 2 16 –19, r 2 18–22 and r 4 20–23 µm), setae r3 longer (60–65 µm) and about 1.5–2 times the length of other podonotal setae. Opisthonotal shield 210–240 µm wide and 205–220 µm long, polytrichous, the setae often with asymmetrical position and different numbers on both sides of the shield: 28–33 setae on each side of the shield present, however the most frequent chaetotactic pattern is that with 31 pairs of setae (in more than half of specimens); opisthonotal setae similar to those on podonotum, but slightly longer (35–50 µm), with tips reaching beyond the bases of following setae. Setae R1 shortened, 20–22 µm long, placed on anterolateral corners of opisthonotal shield or on soft integument beside the shield. Ten pairs of setae placed on dorso- and ventrolateral soft integument (rarely nine pairs if one additional pair of these setae situated on ventrianal shield); the most anterior pair of these setae very short, 12–14 µm in length.

Ventral idiosoma ( Fig. 18 ). Tritosternum with narrow base (26–27µm long), and long and sparcely pilose laciniae (50–58 µm). Presternal area with two pairs of smooth, elongate and transverselly situated shields, and one further pair of triangular shields; anterior pair of elongate shields conspicuously smaller, rarely absent. Sternal shield weakly reticulated, 82–85 µm wide at the level of coxae II, with posterior margin concave and produced into obtuse angle, bearing three pairs of setae; the first pair of sternal setae close to anterior margin of shield. Paragynial shields long, bearing a pair of setae, and largely extending under epigynium. Epigynium 90–94 µm long and 116– 120 µm wide, well reticulated, subtriangular, with figura cuneata well defined. Endogynium a relatively large rounded sac, with laterally reticulated and punctated fields in the form of a drop, and medially with variously formed process having vertical position to longitudinal axis (therefore the process not well discernible in slightly pressed specimens, but directed forward or backward and well observable in sufficiently pressed specimens); the process straight or slightly curved, slender and rod-like, or widened, oblong to trapezoidal, obtusely pointed or more often with bifurcate apex ( Figs 27–30 , 40–45 ). A narrow transverse strip of soft integument present between posterior margin of epigynial shield and anterior margin of ventral shield. Ventral shield well reticulated, with ten pairs of ventral setae (rarely with 11 pairs of setae) and three shorter circum-anal setae. All ventrally inserted setae similar to those on dorsum, mostly 25–40 µm long. Postanal seta slightly longer than para-anal setae.

Gnathosoma . Epistome trispinate, medium spine occasionally with bifurcate apex, and about 1.5–2 times as long as lateral spines; lateral margins of epistome flanked by small denticles; rarely minute additional denticles between the spines present ( Figs 32–33 ). Chelicerae 120–130 µm long; movable digit 55 µm long, with three large teeth and one flat tubercle between two proximal teeth; fixed digit with eight sharp or rounded teeth, including the largest one with proximal position and three denticles located anteriorly to pilus dentilis; dorsal cheliceral seta pilose or serrate ( Fig. 20 ). Corniculi simple, 20 µm long. Hypostome with ten rows of denticles ( Fig. 19 ). Subcapitulum with setae pc slightly longer (23 µm) than setae hp1–3 (18–21 µm). Palptrochanter with seta v1 simple and seta v2 pilose; palpfemoral seta al serrate on one side, palpgenual seta al1 rodlike and seta al2 divided into four or five tines.

Legs ( Figs 22–25 ). Length of legs I–IV: leg I 450–470 µm, leg II 300–320 µm, leg III 250–280 µm and leg IV 410–450 µm. Coxae II and III with small denticles on anterolateral distal margin. Trochanter I with rough anterior edge, seta al with one lateral tine on each side; trochanter IV with small acuminate dorsal tubercle. Seta pd1 on femur IV thickened. Tarsi II and III with setae al2, pl2, av2, pv2 and mv strongly pilose, setae al1 and pl1 slightly pilose and seta pv1 thickened and smooth; tarsus IV 120–160 µm long, with seta pd2 very long (95–105 µm), setae pv2 and pl3 pilose, and seta av1 slightly pilose. Other setae on legs smooth and needle-like.

MALE. Dorsal idiosoma ( Fig. 36 ). Length 375–425 µm, width 190–250 µm (n = 10). Podonotal shield 180–200 µm long, laterally expanded and completely fused to peritrematal shield; opisthonotal shield 190–210 µm long, laterally and posteriorly expanded to capture the setae homological to those placed on soft membrane in female, and completely connected to ventrianal shield. Length of dorsal setae: most podonotal setae 26–35 µm, j 1 25– 29µm, z1 18µm, s1 20µm, s2 17µm, r2 18µm, r4 20 µm, r3 55 µm, opisthonotal setae 30–45 µm, R1 20 µm. Setae R1 sometimes outside the opisthonotal shield, placed on soft integument between dorsal shields.

Ventral idiosoma ( Fig. 37 ). Tritosternum with shortened base and long laciniae (40–45 µm). Presternal area with one pair of small and subtriangular shields. Genital lamella narrowed posteriorly, 60 µm wide, 70 µm long, well sclerotised laterally, unsclerotised and hyaline medially,with anterolateral margins narrowly incised, expanded and produced into small wing-like structures directed laterally; apodemes relatively long, narrow and pointed, well sclerotised, having a small spike on inner margins, and extending to level of sternal setae st2. Holoventral shield present, sternal portion 80 µm wide at the level of coxae II, weakly reticulated, with five pairs of subequal setae (27–30 µm). Ventral setae 25–30 µm long. Other characters as in female.

Gnathosoma . Epistome trispinate, the middle spine slightly longer than lateral spines; anterior margin between spines smooth or with 1–3 minute denticles, lateral margins delicately denticulate ( Fig. 34 ). Chelicerae 100–110 µm long, movable digit 55 µm long,edentate in proximal part, distally with one bigger rounded or sharp tooth and three or four minute denticles placed more distally; spermatotreme in the form of a narrow fissure ( Fig. 21 ). Arthrodial corona modified into a setiform brush. Fixed digit with bidentate hook and a row of 8–11 sharp denticles, some of these denticles often with two minute apices; dorsal seta pilose. Hypostome and subcapitulum as in female. Corniculi simple, 20 µm long. Pedipalps as in female.

Legs. Length of legs I–IV: leg I 450–460µm, leg II 280–295 µm, leg III 2 50 –260µm and leg IV 410–420 µm. Coxae II and III with anterolateral distal margin serrated. Trochanter IV with small dorsal tubercle. Legs II slightly thickened, ventrally spurred ( Fig. 26 ). Spur on femur II thumb-like, having distinct axillar process; the process conical and mounted on common base. Genu II with very small knob-like spur (sometimes hardly observable); spur on tibia II thin, tapered terminally, and directed forward. Tarsus IV 120–130 µm long. Setation of legs as in females.

DEUTONYMPH. Dorsal idiosoma ( Fig. 38 ). Length 340–400 µm, width 190–230 µm (n = 14). Dorsal shield divided into podonotal and opisthonotal shield. Podonotal shield 180–213 µm long and 175–180 µm wide, subpentagonal, with 22 pairs of setae and similar chaetotaxy as in adults but setae r4 placed on soft integument beside the shield. Opisthonotal shield smaller, 115–120 µm long and 145–150 µm wide, subtriangular, bearing 14 pairs of setae. Length of dorsal setae: most podonotal shield setae 25–35 µm, j1 20 µm, z1 13 µm, s1 18 µm, s2 15 µm, r2 16 µm, r3 55 µm, r4 15 µm, and opisthonotal shield setae 25–35 µm. Dorso- and ventrolateral soft integument with 22–27 (most frequently 25) pairs of setae. All dorsal setae smooth and needle-like.

Ventral idiosoma ( Fig. 39 ). Tritosternum similar to that of female (base 25 µm long, and laciniae 50–55 µm long). Two presternal shields small, subtriangular. Sternal shield 135–140 µm long, 65–70 µm wide at the level of coxae II, concave anteriorly, obtusely tapered posteriorly, with shallow constriction between coxae II, with four pairs of sternal setae (20–25 µm long), their bases contiguous to the edge of the shield. Sternal setae st5 placed on soft integument behind the sternal shield. Ventrianal shield 70 µm long and 90 µm wide, suboval, well reticulated (lines of reticulate pattern slightly undulate), with one or rarely two pairs of ventral setae on surface (plus three circum-anal setae). Peritremes and peritrematal shields long and free on soft integument, with anterior ends not connected to podonotal shield and reaching level of setae j2. A pair of small suboval metapodal shields present. Except setae st5 and a pair of setae on ventrianal shield, ventral soft integument with ten pairs of setae;ventral setae smooth and needle-like, relatively short (15–20 µm).

Gnathosoma . Epistome trispinate, with central spine 1.5 times as longas lateral spines; lateral margin sserrate ( Fig. 35 ). Chelicerae 100–120 µm long; movable digit 40–45 µm long, with three teeth; fixed digit with a row of small teeth. Corniculi 18 µm long, subcapitulum and pedipalps as in female.

Legs. The length of legs: leg I 350–370 µm, leg II 220–230 µm, leg III 230–245 µm and leg IV 360–370 µm. Setation as in adults.

Specimens examined. SLOVAKIA. 14 females, 10 males, 3 deutonymphs, Malé Karpaty Mts. , Bratislava City, Botanic Gardens of Comenius University, 48°08’46”N, 17°04’25”E, 135 m a.s.l., 9 May 2012, soil in greenhouse of hygrophilous flora, leg. P. Fenďa ; 3 females, 2 males, 1 deutonymph, ibid., 9 May 2012, soil inthe palm house, leg. P. Fenďa ; 7 females, 1 male, 3 deutonymphs, ibid., 9 May 2012, soil in the palm house, leg. B. Mangová ; 1 female, 1 male, ibid., 9 May 2012, soil in the greenhouse of tropical and subtropical decorative plants, leg. P. Fenďa ; 5 females, 2 males, 1 deutonymph, ibid., 9 May 2012, soil in the greenhouse of tropical and subtropical decorative plants, leg. B. Mangová ; 3 deutonymphs, ibid., 7 June 2012, soil in the palm house, leg. P. Fenďa ; 5 females, 4 males, ibid., 12 December 2012, soil in greenhouse of tropical and subtropical decorative plants, leg. J. Christophoryová & M . Holecová; 12 females, 1 deutonymph, ibid., 12 December 2012, soil in the greenhouse of hygrophilous flora, leg. J. Christophoryová & M . Holecová; 1 female, 2 deutonymphs, ibid., 12 December 2012, soil inthe palm house, leg. J. Christophoryová & M. Holecová. The specimens are deposited at the Acarological Collection in Department of Zoology, Faculty of Natural Sciences, Comenius University in Bratislava, Slovakia, and at the Natural History Museum in Bratislava , Slovakia. GERMANY. Type specimens of Anadenosternum pediculosum Karg & Glockemann, 1995 , deposited at the Natural History Museum in Berlin , Germany (slide numbers: ZMB /Arach 45718, ZMB /Arach 45719, ZMB /Arach 45720, and ZMB /Arach 46288) . KOREA. Female specimen of Anadenosternum azaleense identified by C. Athias-Henriot (1980), and deposited at the Hungarian Natural History Museum in Budapest , Hungary ( HNHM Meso-4428).

Remarks. Unfortunately, we could not locate the type specimens of Anadenosternum azaleense reportedly deposited in the collection of the Chair of Zoology, Faculty of Agricultural Sciences, State University of Ghent, Belgium. Staff of the Zoology Museum of Ghent University, as well as other colleagues, report that there are no specimens of A. azaleense in their collections. That material seems to be not available and may be lost.

This is the first record of the genus from Slovakia and first description of the deutonymph of Anadenosternum . The species colonises all the greenhouses in the botanic garden: the greenhouse of tropical and subtropical decorative plants (average air temperature of 22–24 °C and 75–80% humidity); the greenhouse with lotus, water lily and royal victoria plants oriented on hygrophilous flora of tropical rain forests (average air temperature of 24– 26 °C and 75–85% humidity); the palm house containing a collection of palms, cycads and araucaria plants (average air temperature of 18–22 °C and 65–70% humidity).

Figures

FIGURES 17 – 21. Anadenosternum azaleense. 17. Female, dorsal idiosoma; 18. Female, ventral idiosoma; 19. Female, ventral hypostome, and pedipalp; 20. Female, lateral chelicera; 21. Male, lateral chelicera. Scale bars 100 µm (Figs 17 – 18), 20 µm (Figs 19 – 21).

FIGURES 22 – 35. Anadenosternum azaleense. 22. Female, leg I without tarsus, dorsal view; 23. Female, leg II, dorsal view; 24. Female, leg III, dorsal view; 25. Female, leg IV, dorsal view; 26. Male, leg II without tarsus, anterolateral view; 27 – 30. Female, endogynium, variant forms of medial process; 31. Male, genital lamella; 32 – 33. Female, epistome, variant forms; 34. Male, epistome; 35. Deutonymph, epistome. Scale bars 100 µm (Figs 22 – 26), 20 µm (Figs 27 – 35).

FIGURES 36 – 37. Anadenosternum azaleense, male. 36. Dorsal idiosoma; 37. Ventral idiosoma. Scale bars 100 µm.

FIGURES 38 – 39. Anadenosternum azaleense, deutonymph. 38. Dorsal idiosoma; 39. Ventral idiosoma. Scale bars 100 µm.

FIGURES 40 – 48. Endogynium of females. 40 – 45. Anadenosternum azaleense. 46 – 48. Anadenosternum okalii sp. nov. Not scaled.