Kayella pannonica, Kalúz, Stanislav, 2008

Kalúz, Stanislav, 2008, A new chigger mite (Acari: Prostigmata: Trombiculidae) from Central Europe, Zootaxa 1875, pp. 32-38 : 32-37

Kayella pannonica sp. n.

Description. Larva (holotype). SIF – 4B–N–3–2–0–0–1–0–0–0–0; fsp = 7–7–7; fPp = B–B–BBB; fCx = 1– 1–2; fSt = 2–2; PL>AM>AL; fDS = 2H–8(9)–8–4(5)–6(7)–6–4–2–2 = 42–44; VS = 36–41; NDV = 78–85; Ip = 569 – (average = 641) – 707.

Dorsum ( Fig. 1 ). Scutum subquadrate, slightly wider than long, with AL, AM, PL and two sensillae. Big scutal puncta cover prevailing part of scutum. Sensilla expanded, its head usually globose; stem shorter than head and serrate in distal part. Sensilla 30 long, globose head 14 wide. Oval eyes (2 + 2) in ocular plates, eyes laterally above PL.

Scutum: (holotype /min.–average–max. in paratypes; n = 11): AW (49/43–48–52); PW (63/57–61–66); SB (31/25–30–32); ASB (21/20–22–25); PSB (21/20–22–24); SD (42/40–43–48); AP (31/29–32–35); AM (29/ 26–29–32); AL (25/23–26–31); PL (38/34–38–43); PW>AW>SD; SB>PSB>ASB.

Humeral setae 42–46 and dorsal 31–41 μm long, thickly barbed, dorsal setae arranged in irregular rows, rows varying in position and also in number of setae.

Venter ( Fig. 2 ). Two pairs of sternal setae. Third coxa with 2 setae, arranged in tandem to proximal margin of coxa. Ventral side generally with 36–41 thickly barbed setae, irregularly arranged, proximal setae shorter to caudal. Length of ventral setae vary (21–32).

Gnathosoma ( Fig. 3 ). Galeala barbed. Palpes 49 μm long, 3–pronged palptibial clow slender, 17 long, with deeply indented prongs. Cheliceral blade ( Fig. 4 ) of normal contour.

Legs ( Figs. 5–7 ). With praetarsus, claws and normal empodia. All setae on legs barbed, slender, relatively short. Specialized setae on leg segments: Leg I – S1, f1, (PT´, ST, pST) = N, 2 tibialae, 1 microtibiala, 2 genualae, 1 microgenuala; Leg II – S2, f2, PT´´= N, 2 tibialae; Leg III – 1 tibiala. Number of ciliate setae on leg segments (leg formula):

Leg I: Cx (1) – Tr (1) – Fe (6) – Ge (4) – Ti (8) – Ta (22)

Leg II: Cx (1) – Tr (1) – Fe (6) – Ge (3) – Ti (6) – Ta (16)

Leg III: Cx (2) – Tr (1) – Fe (5) – Ge (3) – Ti (6) – Ta (14)

Length of leg segments: (holotype /min.–average–max. in paratypes)

Leg I: Cx (54/46–50–54), Tr (29/20–26–31), Fe (54/38–45–54), Ge (29/24–28–31), Ti (32/31–32–34), Ta (57/52–55–57), total length (255/217–236–255);

Leg II: Cx (54/46–50–55), Tr (25/21–25–31), Fe (38/34–37–40), Ge (20/17–19–21), Ti (24/23–25–32), Ta (46/42–45–46), total length (207/192–200–216);

Leg III: Cx (55/44–47–55), Tr (38/28–32–38), Fe (43/37–42–46), Ge (21/18–21–24), Ti (31/29–31–32), Ta (57/44–52–57), total length (245/207–224–245);

Discussion. Brennan & Goff (1977) followed the definition given by Vercammen-Grandjean (1960) for species from the Western Hemisphere (Type species: Euschoengastia lacerta Brennan, 1948 ). American species ( Goff & Whitaker, 1984) can be easily distinguished from the Eastern Palearctic ones (with 2 genualae I, subterminala and parasubterminala I present) by having a single genuala I, lacking subterminala and parasub terminala I ( Kudryashova, 1998). Another species Cordiseta (Kayella) vercammeni (Kolebinova, 1983) , included in the fauna of Bulgaria ( Kolebinova, 1992), was synonymised with Cordiseta (Kayella) anatolica (Kepka, 1962) which was recently placed in the genus Schoutedenichia Jadin & Vercammen-Grandjean, 1954 ( Kudryashova, 1998) .

Hushcha (1966) revealed the larvae of Kayella bobaci on Marmota bobac in summer (July) and those of Kayella parumsetosa on Apodemus sylvaticus and Rhombomys opimus were found in December ( Schluger & Amanguliev, 1975). The larvae of Kayella pannonica sp. n. are mostly occurred from March to May. The spring cases of human skin eruption have been known from SW Slovakia for several decades. The symptoms often appear after tree planting and walking in oak forest from March to June, which is medically different from the most important European chiggers, Neotrombicula autumnalis (Shaw, 1790) and N. vulgaris (Schluger, 1955) , that occur from the second half of July to autumn. The root causes of these symptoms are still unknown because of the vague information and undefined localities.

Differential diagnosis. Up to date, two Eastern Palearctic species, K. bobaci ( Hushcha, 1966) and K. parumsetosa Schluger & Amanguliev, 1975 have been known. The differences between K. pannonica sp. n. and these two species are as the following:

Kayella pannonica sp. n.: fCx = 1–1–2, NDV = 78–85, fD = 2H–8(9)–8–4(5)–6(7)–6–4–2–2 = 42–44, VS = 36–41; ASB<PSB, AP>AM, smaller scutum, eyes (2+2) in ocular plate.

Kayella bobaci : fCx = 1–1–1, NDV = 76–79, fD = 2H–8(9)–8–6–6–4–2 = 36–37, ASB>PSB, AP<AM, bigger scutum, eyes (2+2), no ocular plate.

Kayella parumsetosa : fCx = 1–1–1, NDV = 66, fD = 2H–6–6–6–6–4–2=32, ASB>PSB, AP=AM, bigger scutum, eyes rudimentar (1+1).

Etymology: The specific name ( pannonica ) reflects the zoogeographic name of Pannonian province.

Material examined

Holotype: SW– Slovakia, Bratislava, N–48°05'43", E–17°09'44", 125 m altitude, thermophile foreststeppe oak-hawthorn forest (Crataegeto-Quercetum), 1 larva from soil and leaf litter, 12 June 2006. Paratypes: 1 larva, same collecting data. Bratislava, N–48°04'21", E–17°12'02", 125 m altitude, thermophile oak-hawthorn forest (Crataegeto-Quercetum) in similar environment, 10 larvae from Clethrionomys glareolus , 21 March 1990; Strázovské vrchy Mts., Timoradza, N–48°48'28", E–18°15'40", 425 m altitude, thermophile oak-hawthorn forest (Crataegeto–Quercetum), 25 larvae from soil and leaf litter, 15 March 2007. Holotype (SZ 6886) and 10 paratypes (SZ 6887) are deposited in Slovak National Museum, Bratislava. Remaining paratypes are deposited in the authors´collection.

Figures

FIGURE 1. Kayella pannonica sp. n. (holotype). Dorsal idiosoma. Scale bar: 100 μm

FIGURE 2. Kayella pannonica sp. n. (holotype). Ventral idiosoma. Scale bar: 100 μm

FIGURES 3 - 4. Kayella pannonica sp. n. (holotype). 3, gnathosoma; 4, chelicera. Scale bars: 100 μm

FIGURES 5 – 7. Kayella pannonica sp. n. (holotype). 5, leg I. 6, leg II. 7, leg III (A, dorsal; B, ventral; Scale bars: 100 μm