Ixodes himalayensis sp. n. (Acarina: Ixodidae) Parasitizing Small Mammals in Himachal Pradesh, India

Abstract

Ixodes himalayensis sp. n. is described from female, nymph, and larva taken on rodents and a shrew from various localities in Himachal Pradesh, India. The species is related to I. redikorzevi Olenev, 1927, which is known to parasitize small mammals and birds in several localities in southwestern Russia, Greece, Bulgaria, Egypt, and Afghanistan. The new Ixodes species described below was collected by one of us (S.M.K.), during a survey of hematophagous arthropods in the Himalayan region of Himachal Pradesh, India. All the measurements in the descriptions are given in millimeters and were taken at the longest or the widest point. The illustrations were prepared from alcohol-preserved specimens with the aid of a camera lucida. Some of the larvae were mounted on slides in Hoyer's medium for studying the finer details and the chaetotaxy. Ixodes himalayensis sp. n. The Himalayan Small-mammal Ixodid (Figs. 1-16) Holotype Female, V.R.C. No. A-82035, Mus musculus, Palchan (altitude approximately 2,310 m), Kulu district, Himachal Pradesh, India, 3 October 1967, S. M. Kulkarni, deposited in the tick collection of the Virus Research Centre, Poona. Paratypes Eleven 9 9, 31 nymphs, 42 larvae, details as given in Table I. Paratypes deposited in collections of the Virus Research Centre, Poona; Indian Museum, Calcutta; British Museum (Natural History), London; and Rocky Mountain Laboratory, Hamilton, Montana. Female (Figs. 1-7) Body: Smallest specimen almost unengorged, oval, widest at level of coxae IV, 2.66 long, 1.51 wide. Largest specimen almost fully engorged, oblong, 5.11 long, 3.24 wide. Dorsal and ventral integumental areas thickly covered with moderately long white setae (Figs. 1, 2). Capitulum (Figs. 3, 4): 0.73 to 0.85 long, 0.46 to 0.56 wide. Basis capituli dorsally widest at juncture of palpi, converging gradually posteriorly to form well-developed sharp triangular cornua; posReceived for publication 13 January 1969. * The Virus Research Centre is maintained by the Indian Council of Medical Research. The Centre also receives a grant (3x4307) of the PL 480 Funds from NIH, USPHS, through the Indian Council of Medical Research. terior margin between cornua straight; porose areas large, clearly defined, subtriangular in outline. Basis capituli ventrally with well-developed posteriorly directed auriculae. Two pairs of minute posthypostomal setae. Palpi widest near apex of segment 2, greatest width about 0.16; segment 2 almost as long as 3, their combined length 0.54 to 0.61. Setae numerous, as illustrated (Figs. 3, 4). Hypostome (Fig. 5): Denticle-bearing portion 0.40 to 0.43 long; apex sharply pointed. Dental formula 3/3 in anterior half, thence 2/2 to base. Scutum: 1.12 to 1.40 long, 0.99 to 1.10 wide, widest near midlength. Scapulae sharp and pointed. Lateral carinae indistinct. Cervical grooves as shallow depressions, limited to anterior %, narrow and parallel anteriorly, wide and divergent posteriorly. Punctations large and distinct, moderately numerous, distributed all over scutum. Seta moderately long, white, distributed as illustrated (Fig. 1). Legs (Figs. 1, 2, 7): Moderately long. Coxa I with two spurs, outer small, triangular, inner long, tapering gradually to sharp points; II and III with well-developed triangular outer spur, and small distinct inner spur like projection; IV with only subtriangular outer spur. Trochanters lack spurs. Tarsus I 0.59 to 0.67 long, metatarsus I 0.31 to 0.41 long; tarsus IV 0.49 to 0.58 long, metatarsus IV 0.38 to 0.47 long. Pulvilli reach distal curvature of claws. Spiracular plate (Fig. 6): Outline circular, diameter about 0.22. Genital aperture: Situated at level between coxae III and IV. Genital groove rounded anterior to genital aperture, gradually divergent posteriorly, terminating short of posterior margin. Anal groove: Horseshoe-shaped, terminating short of posterior margin. Anus longitudinal slit, surrounded by two semilunar valves; each valve with three anal setae. Nymph (Figs. 8-14) Body: Shape as in female. Smallest specimen almost unengorged, 1.19 long, 0.64 wide; largest specimen almost fully engorged, 2.59 long, 1.65 wide. Dorsal and ventral integumental areas densely covered with long white setae. Capitulum (Figs. 10, 11): 0.25 to 0.28 long, 0.17 to 0.22 wide. Basis capituli dorsally and ventrally similar to female in outline, except that auriculae slightly smaller. Palpi widest near base