Radfordia (Microtimyobia) clethrionomys Fain and Lukoschus, 1977

Bochkov, Andre V., 2011, Mites of the subgenus Microtimyobia (Acariformes: Myobiidae: Radfordia) and their host-parasite relationships with cricetid rodents (Cricetidae) 2954, Zootaxa 2954 (1), pp. 1-86 : 20-23

2. Radfordia (Microtimyobia) clethrionomys Fain and Lukoschus, 1977

( Figs. 9 , 10 )

Radfordia (Microtimyobia) lemnina clethrionomys Fain and Lukoschus, 1977: 64 , figs. 86, 105

Radfordia (Microtimyobia) clethrionomys, Bochkov 1995: 485

Radfordia (Microtimyobia) lemnina rutila Fain and Lukoschus, 1977: 64 , figs. 104, 87; syn. nov.

Radfordia (Microtimyobia) lemnina mikado Uchikawa, Nakata and Takahashi, 1997: 678 , figs. 6, 13, 24; syn. nov.

Diagnosis. FEMALE ( Fig. 9 ). Subcapitular setae m generally with 3 tines (in some specimens with 2 or 4 tines). Setae vi distinctly wider than e2. Setae e1 and f1 narrow lanceolate. Distances c1-d1 and d1-d2 subequal. Vulvar region distinctly ornamented. Setae ps3 distinctly developed, slightly curved. Setae ag2 at least twice longer than ag1. Setae 1b and 1d about 1.5 times thicker than 1a. Setae 2a and 3a whip-like, much longer than 2b. Trochanter I with distinct ventral projection and without tubercles. Measurements of paratype (Fain & Lukoschus): body, including gnathosoma, 375 long, 225 maximum wide. Lengths of setae: vi 53, si 104, se 63, c1 57, d1 51, d2 58, e1 27, e2 45.

MALE ( Fig. 9 ). Subcapitular setae m membranous with 2 tines (in some specimens with 1 tine). Genital cone slightly widened, length/width ratio 1.6:1, with triangular lateral projection. Bases of setae vi situated anterior to setae ps2. Setae f1 1.1–1.3 times shorter than e2. Posterior end of opisthosoma with tubercles. Setae 2a whip-like, much longer than 2b. Trochanter I with distinct ventral projection and without tubercles. Measurements of holotype (Fain & Lukoschus): body, including gnathosoma, 340 long, 210 maximum wide. Aedeagus 117 long. Lengths of setae: si 27, se 75, e1 60 –66, e2 27, f1 24.

FEMALE TRITONYMPH ( Fig. 10 ). Setae f2 and h2 stick-like, other dorsal idiosomal setae narrow lanceolate. Length of setae 3a and 4a highly variable. Tarsus IV with 4 setae.

Remarks. (i) Radfordia lemnina rutila Fain and Lukoschus, 1977 was described from Myodes rutilus from Sweden ( Fain & Lukoschus 1977). Later on, this subspecies was considered as a subspecies of Radfordia clethrionomys ( Bochkov 1995) and finally received the full species rank ( Bochkov & Mironov 1998). I re-examined the type series and additional materials from different hosts and geographical localities of these species, R. clethrionomys and R. rutila and think now that they are conspecific. Therefore I consider R. rutila syn. nov. as a junior synonym of R. clethrionomys .

(ii) Uchikawa et al. (1997) described a new subspecies, Radfordia lemnina mikado Uchikawa et al., 1997 from Myodes rutilus mikado from Japan. In this subspecies, the male genital cone has the triangular shoulders, which is a very characteristic feature of Radfordia clethrionomys (= R. rutila ) ( Bochkov & Mironov 1998) associated with voles of the genus Myodes . Uchikawa et al. (1997) suggested that R. lemnina mikado might be more allied to R. rutila and R. clethrionomys based on the shape of the genital cone. I compared the description of Radfordia lemnina mikado with adult and immature stages of Radfordia lemnina and Radfordia clethrionomys (immatures were primarily unknown for the latter species) and did not find any significant differences between this subspecies and the latter species. For this reason I consider subspecies R. lemnina mikado syn. nov. as a junior synonym of Radfordia clethrionomys .

(iii) Fain & Lukoschus (1977) determined females (males were absent) parasitizing M. gapperi ( USA) as Radfordia lemnina . It should be noted that females of R. lemnina and R. clethrionomys are almost indiscernible. I examined several females and female TNs from Myodes gapperi , including Fain’s material. They are similar to R. clethrionomys but examination of males from its type host is necessary for more accurate determination of these specimens. I treat, therefore, them as Radfordia aff. clethrionomys (see below).

Type host and locality. Myodes glareolus from Belgium ( Fain & Lukoschus 1977).

Hosts and distribution. This species is associated with Palearctic voles of the genus Myodes ( Bochkov 2009b) ; the records of Radfordia lemnina from Myodes gapperi and Myodes californicus in North America ( Fain & Lukoschus 1977), probably should refer to this species.

It was recorded from:

Myodes glareolus from England ( Radford 1935), Italy, Holland, and Belgium ( Fain & Lukoschus 1977), Czech Republic ( Dusbabek & Daniel 1975); Bulgaria ( Sosnina et al. 1969; Beron 1973), Ukraine and various parts of Russia ( Bochkov 1995);

Myodes centralis from Kazakhstan and Kirghizia ( Bochkov 1995; Chirov et al. 1997).

Myodes rutilus from Sweden ( Fain & Lukoschus 1977), Russia (Chelyabinsk Prov., Tuva) ( Bochkov & Mironov 1998; present data), Japan ( Uchikawa et al. 1997);

Myodes gapperi from USA (New York) ( Fain & Lukoschus 1977) (confirmation needed);

Myodes californicus from North America ( Fain & Lukoschus 1977) (confirmation needed).

Material examined. Myodes glareolus —Male holotype ( IRSNB), BELGIUM: de Heer Agimont, September 1968, coll. unknown; 1 male and 1 female paratypes ( ZISP), BELGIUM: Pescasseroli , 16 October 1972, coll. F. Lukoschus ; 18 males and 24 females, 16 female TN, and 4 male TN, UKRAINE: Kiev Prov., 1957, coll. G. Gushcha ; 23 males, 22 females, and 8 female TN, UKRAINE: Zakarpatie Prov., Polonina Rovnaya Mountain , July 1959, coll. S. Vysotskaya ; 18 males, 28 females, 10 female TN, and 5 male TN, RUSSIA: Karelia, Sredniy Island , 24–29 July 1979, coll. E. Dubinina ; 4 males and 4 females, RUSSIA: Kaliningrad Prov., 12 May 1979, coll. E. Dubinina ; 1 male and 1 female, RUSSIA: vicinity of Saint-Petersburg, 3 April 1981, coll. E. Dubinina ; 29 males, 28 females, 15 female TN, and 11 male TN, RUSSIA: Pskov Prov., Sebezh Distr., near Anninskoe Lake , May 1991, coll. A. Bochkov ; 4 females, RUSSIA: Ivanovo Prov., 23 June 1953, coll. unknown ; 13 males and 10 females, RUSSIA: Volzhsko-Kamskiy Reservation , 4 October 1968, coll. E. Dubinina ; 18 males and 27 females, RUSSIA: Chelyabinsk prov., near Shugunyak Lake , June 1975, coll. E. Dubinina ; 2 females, RUSSIA: Bashkiria, Kukshik Mountain , 3 July 1975, coll. E. Dubinina.

Myodes centralis — 3 males, 7 females, and 4 female TN, KAZAKHSTAN: vicinity of Bol’shoe Alma-Atinskoe Lake , August 1981, coll. E. Dubinina ; 5 males, 8 females, 7 female TN, KIRGHIZIA: Terskey Ala-Tau Mountain Ridge , Chon-Kyzyl-Su Canyon, 9 July 1953, coll. A. Petrova.

Myodes rutilus — 1 male [holotype of Radfordia lemnina rutila (IRSNB) ], 1 male and 1 female [paratypes of Radfordia lemnina rutila (ZISP) ], SWEDEN: Bjorkliden , 11 August 1966, coll. Edler ; 14 females and 2 female TN, RUSSIA: Chelyabinsk Prov., near Shugunyak Lake , 19 June 1975, coll. E. Dubinina ; 3 female TN ( AVB 09- 1204 - 001 ), RUSSIA: Tuva, Erzinskiy Distr., SE Tore-Khol’ Lake , 50º01'29"N, 94º03'23"E, 20 September 2009, coll. A. Abramov (AA #831) ; 1 male, 4 females, 3 female TN (1 pharate), and 1 male TN ( AVB 09-1204 - 002 ), RUSSIA: Tuva, Mongun-Tayginskiy Distr., S Khindiktig-Khol’ Lake , 2318 m, 50º19'23,9"N, 89º47'54,2"E, 13 August 2008, coll. A. Abramov (AA #36).

Type depositions. Radfordia lemnina clethrionomys —IRSNB, female holotype (examined); Radfordia lemnina rutila —IRSNB, female holotype (examined); Radfordia lemnina mikado —NSMT, female holotype (Ac 10714) (not examined).

Figures

FIGURE 9. Radfordia (M.) clethrionomys Fain and Lukoschus, 1977, details—genital cone of males and setae m.

FIGURE 10. Radfordia (M.) clethrionomys Fain and Lukoschus, 1977 from Myodes glareolus, female tritonymph. A, idiosoma in dorsal view; B, same in ventral view; C, leg IV in dorsal view. Scale bars: A, B = 100 µm; C = 50 µm.