[Differentiation of closely related species Hyalomma anatolicum and H. excavatum (Acari: Ixodidae) based on a study of all life cycle stages, throughout entire geographical range].
Species status is stated for Hyalomma anatolicum and H. excavatum, based on numerous material from the territory of their distribution. The differentiation of species is recovered for all stages of the life cycle. Diagnosis of Hyalomma anatolicum. Female: small tick--length of scutum commonly less than 2 mm; width of scutum commonly less than 1.9 mm; color of scutum, gnathosoma and coxae light, yellowish- or reddish-brown; whitish enameled pigment on scutum absent; posterolateral ledges of scutum weakly expressed or absent; cervical and lateral grooves more shallow (than in H. excavatum) (fig. 1); setae of scutum, alloscutum, sternal setae and ventromedian setae of second article of palpae more tapering to the apex, narrow rounded or acute (fig. 2, 1, 2, 5, 8). Male: small tick--length of conscutum, as a rule, less than 4 mm; width of scutum, as a rule, less than 2.3 mm; shape of conscutum marrow oval (fig. 3), widest in the midlevel; color of conscutum, anal shields, gnathosoma and coxae light, yellowish- or reddish-brown; whitish enameled pigment on conscutum absent; caudal depression with less dense and more large punctuations (than in H. excavatum); ridges lateral to caudal field less high and sharp (than in H. excavatum); posteromedian groove separated from parma by contiguous punctuations or smooth non high area; setae of conscutum conus-like, more sharpening (fig. 4, 1-3); posterior dorsal margin of gnathosoma straight or slightly concave (fig. 4, 8); segments of leg IV not swallowed. Nymph: large tick (see description). Scutum more narrow. Dorsal tale of spiracular plates clear expressed, marginal perforations distant from margin of spiracular plates at the base of tale (fig. 5, 3); anterolateral side of basis capituli approximately equal to half of gnathosoma width; ventrally lateral projections of gnathosoma situated in posterior half of capitulum base (fig. 5, 4, 5). Hypostome more longer and narrow (fig. 5, 5). Larva: large tick (see description). Diagnosis of Hyalomma excavatum. Female: large tick--length of scutum commonly more than 2 mm; width of scutum commonly more than 1.9 mm; color of scutum, gnathosoma and coxae dark, reddish- or black-brown; whitish enameled pigment commonly present; posterolateral ledges of scutum clearly expressed; cervical and lateral grooves more dipper (than in H. anatolicum) (fig. 7). Setae of scutum, alloscutum, sternal setae and ventromedian setae of second article of palpae more stick-like, more widely obtuse (fig. 8, 1-5). Male: large tick--length of conscutum more than 4 mm; width of scutum more than 2.3 mm; shape of conscutum wide oval (fig. 9), widest in posterior half of length; color of conscutum, anal shields, gnathosoma and coxae dark, reddish- or black-brown; whitish enameled pigment often present; caudal depression with more dense and more small punctuations (than in H. anatolicum); ridges lateral to caudal field more high and sharp (than in H. anatolicum); posteromedian groove separated from parma by strong elevations fused with paraparmal festoons; setae of conscutum more obtuse, often stick-like (fig. 10, 1, 2); posterior dorsal margin of gnathosoma straight or lightly concave. (fig. 10, 3); segments of leg IV swallowed. Nymph: small tick (see description). Scutum more wide. Dorsal tale of spiracular plates weakly expressed, marginal perforations not distant from margin of spiracular plates at the base of tale (fig. 11, 3); anterolateral side of basis capituli clearly shorter than half of gnathosoma width; ventrally lateral projections situated in the middle of or anterior half of capitulum base (fig. 11, 4, 5). Hypostome more shorter and wider (fig. 5, 5). Larva: small tick (see description). Established taxonomical independence of H. anatolicum and H. excavatum is confirmed by several criteria: external morphology (see diagnoses); morphometrical data (see diagnoses and fig. 12, 13); size inversion: larva and nymph of H. anatolicum are large, but females and males are small; while H. excavatum vise versa--larva and nymph are small, but adults--large; host specialization of immature stages: larvae and nymphs of H. anatolicum, as rule, parasitize larger mammals (cattle, camels), while immature stages of H. excavatum parasitize smaller mammals (rodents, hares); presence of sympatry areas: almost entire area of H. excavatum include in area of H. anatolicum and cattle help to mix its populations.
D000349:Africa; D000818:Animals; D001209:Asia, Central; D001211:Asia, Western; D005060:Europe; D005260:Female; D026863:Ixodidae / Q000033:anatomy & histology / Q000145:classification* / Q000502:physiology; D007814:Larva; D008297:Male; D009758:Nymph / Q000033:anatomy & histology; D013045:Species Specificity