Yunkeracarus ascanicus Zabludovskaya, 1989

Bochkov, Andre V., Zabludovskaya, Svetlana & Oconnor, Barry M., 2008, Phylogeny and systematics of the endoparasitic astigmatid mites (Acari: Sarcoptiformes) of mammals: families Gastronyssidae, Lemurnyssidae, and Pneumocoptidae, Zootaxa 1951 (1), pp. 1-152 : 122-123

10. Yunkeracarus ascanicus Zabludovskaya, 1989

( Figs. 65 , 66 )

Yunkeracarus ascanicus Zabludovskaya 1989: 64 , figs. 1–6; 1990: 32.

Yunkeracarus stepposus Zabludovskaya 1990: 34 , figs. 1–6, syn. nov.

Redescription. FEMALE (holotype). Body, including gnathosoma, 350 long (340 in one paratype), 145 wide (175). Propodonotal shield with widely rounded posterior margin, length 50 (48), maximum width 60 (50). Setae si 29 long (26), subequal to se 28 long (25). Distance se–se 69 (66), about 5 times greater than si–si, 14 (13). Bursa copulatrix opening dorsal. Sternum about 19 long. Posterior projections of coxal fields I distinctly developed, about 10 long, 16 wide. Distance between distal ends of apodemes II 32 (26). 2 pairs of weakly developed folds present ventrally on propodosoma posterior to coxal fields II. Distance 4a–4a 26 (23), 1.8 times greater than ps3–ps3, 17 (13). Alveoli of setae h1 and h3 absent. Legs III and IV subequal in length, about 110 and 125 long, respectively (excluding pretarsus). Setae cG I filiform, about 10 long (10), cG II microspines, about 3 long. Setal lengths: 1a 13 (13), c3 14 (14), cp 26 (23), h2 147 (130), vF I 21 (22), vF II 30 (25), mG I–II 25–27, gT I–II about 4, solenidia ϕI–II about 8, ω 1 I–II about 10.

Measurements of Y. stepposus paratype (female). Body, including gnathosoma, 335 long, 185 wide; propodonotal shield 50 long, 55 maximum wide; sternum 20 long, distance between distal ends of apodemes II 22, between bases of setae si–si, se–se, 4a–4a, and ps3–ps3 13, 70, 26, and 16 long, respectively; setal lengths: si 26, se 23, 1a 12, c3 14, cp 25, h2 125, vF I–II about 22, mG I–II about 26, gT I–II about 3, ϕI–II about 9, solenidia ω 1 I–II about 10.

MALE (2 specimens). Body, including gnathosoma, 265–295 long, 140–155 wide. Propodonotum as in female. Propodonotal shield about 50 long and 60 maximum wide. Setae si 27–29 long, about 1.3 wide times longer than se, 20–21 long. Distance se–se 60–65, more than 6 times greater than si–si, 10–11. Sternum 18–23 long. Posterior projections of coxal fields I distinctly developed, about 9 long, 15 wide. Distance between distal ends of apodemes II 20–30. Two pairs of weakly developed folds present ventrally on propodosoma posterior to coxal fields II. Aedeagus 57–60 long, its posterior end situated at level of setae g. Length and width of postgenital shield subequal, about 23. Distance g–g about 25, about 2.5 times greater than ps3–ps3, 9–10. Alveoli of setae h1 and h3 absent. Legs III and IV subequal in length. Setae cG I filiform, about 12 long, cG II microspines, about 5 long. Setal lengths: c3 13–14, cp about 22, h2 114–126, vF I about 20, vF II about 27, mG I about 18, mG II about 23, gTI–II about 4, solenidia ϕI–II about 6, ω 1 I–II about 8.

Type material examined. Yunkeracarus ascanicus : Female holotype and female paratype ( SIZ 629/86) ex Microtus socialis [ Apodemus sylvaticus as indicated in the original publication was actually an editorial mistake], UKRAINE: Kherson Reg., 149 km SE Kherson, “Ascania Nova” National Reservation, block 68, 46°08'08"N, 33°23'25"W, 17 July 1986, coll. S. Zabludovskaya. Yunkeracarus stepposus : Female holotype and female paratype ( SIZ 487/20) ex Microtus socialis , same locality, block 89, 13 July 1986, coll. S. Zabludovskaya.

Type deposition. Holotype is deposited in SIZ.

Remarks. According to the diagnosis of Zabludovskaya (1989, 1990), Y. stepposus differs from Y. ascanicus , known only from two females, by the weakly sclerotized idiosoma and legs, short sternum, the presence on tarsi I–III of three and two claw like setae, respectively, and by some measurements. Actually, the two female specimens of Y. ascanicus are teneral and therefore, weakly sclerotized. The sternal length in Y. ascanicus does not differ from that of Y. stepposus being 19–20 long, but the posterior half of the sternum in these specimens is indistinct due to weak sclerotization. The comparative examination of tarsal setation did not reveal any distinctions between these two species. The measurements of Y. ascanicus and Y. stepposus are completely compatible (see descriptions). Therefore we consider Y. stepposus as a junior synonym of Y. ascanicus , syn. nov.

Our comparison of type specimens of Y. microti and Y. ascanicus shows their similarity. The measurements of these two species are overlapping or almost overlapping, and distinctions in qualitative characters are not observable. A difference in the position of setae cG II was mentioned by Zabludovskaya (1990). According to Smith et al. (1985: 482, fig. 1) setae cG II are situated in the basal part of the segment in Y. microti , whereas in Y. ascanicus (= Y. stepposus ) these setae are situated in the median part of genu II ( Zabludovskaya 1990). Based on our observations, in Y. microti setae mG II are also situated in the median part of the segment, but the seta is visible only if legs II of the observed specimen are extended. In mounted mites these legs are quite often bent and, therefore, setae mG II seem to be positioned at the genual base. The only difference between Y. ascanicus and Y. microti is some disparity in the length ratio of setae c3 and cp. In Y. microti from Microtus pennsylvanicus ( USA), setae c3 are subequal to cp or up to 1.1–1.3 times longer than these setae (1.5 times longer in Belgian specimens from Microtus arvalis ), whereas in Y. ascanicus setae c3 are 1.6– 1.8 times longer than cp. We suppose that additional sampling of mites from different species of Microtus from different localities could help to clarify whether Y. ascanicus and Y. microti are actually separate species.

Figures

FIGURE 65. Yunkeracarus ascanicus Zabludovskaya, 1989, female. A, dorsal view; B, ventral view; C, sternum; D, tarsus I in dorsal view; E, tarsus I in ventral view; F, tarsus III in ventral view; G, tarsus IV in ventral view. Scale bars: 100 µm (A, B), 50 µm (C–G).

FIGURE 66. Yunkeracarus ascanicus Zabludovskaya, 1989 (= stepposus Zabludovskaya, 1990), female parastype. A, dorsal view; B, ventral view; C, tarsus I in dorsal view; D, same in ventral view; E, tarsus II in dorsal view; F, same in ventral view; G, tarsus III in dorsal view; H, same in ventral view; I, tarsus IV in dorsal view; J, same in ventral view. Scale bars: 100 µm (A, B), 50 µm (C–J).