Systematics of chigger mites of the genus Hirsutiella Schluger et Vysotzkaya, 1970 (Acari, Trombiculidae)

A.A. Stekolnikov

Entomologicheskoe obozrenie, 80(1): 219-242 (2001) (In Russian, English summary).

S U M M A R Y

Revision of the genus Hirsutiella Schluger et Vysotzkaya, 1970 has been performed. A new species H. alpina sp.n. is described from southern Daghestan, Northern Ossetia, Krasnodar Territory and Turkey. The new species is closely related to H. steineri (Kepka, 1966) and differs in the greater number of idiosomal setae (NDV=203—271 vs. 157—213), longer setae (Dmax=70—95 vs. 58—76, H=77—94 vs. 60—83) and legs (Ip=1236 vs. 1094, TaIII=113—133 vs. 90—112) and larger scutum (AW=84 vs. 77, PW=101 vs. 95, SD=66 vs. 62). H. steineri and H. llogorensis (Daniel, 1960) are reported from Russia (the Western and Northern Caucasus) for the first time; H. steineri is also reported for the first time from Armenia, and H. hexasternalis Kudryashova, 1998, from Chelyabinsk Province and Kazakhstan (Karaganda Province).

Methods of multivariate analysis (factor and discriminant analysis, multidimensional scaling) were used for resolution of diagnostic problems in the genus Hirsutiella. Discriminant functions produced by the computer programme DIADIS (A.L. Lobanov, Zoological Institute, Russian Academy of Sciences) allow reliable identification of the representatives of the genus. Pattern of characters variances in Hirsutiella has also been studied, and main relations between the characters are shown. Dependence of the size parameters on climatic conditions, previously reported by the author for the genus Neotrombicula, is also revealed in Hirsutiella. The species of the smallest size, H. llogorensis, has the southernmost distribution and occurs at lowest altitudes. H. steineri and H. alpina are primarily alpine species, and H. zachvatkini is a northern one, while H. llogorensis inhabits mostly forests in the foothills of southern European mountains and the Caucasus.