VARIABILITY IN CUTICULAR HYDROCARBONS AND PHENOTYPIC DISCRIMINATION OF IXODES-RICINUS POPULATIONS (ACARINA, IXODIDAE) FROM EUROPE

The cuticular hydrocarbon composition and a stepwise discriminant anal ysis are used to elucidate the phenotypic relationships of 66 populati ons of Ixodes ricinus in Europe. The method correctly allocates Ixodes persulcatus (outgroup) populations away from the main cluster of I. r icinus samples and separates the samples into ten relatively defined c lusters of specimens. Populations from Poland are inseparable from sam ples collected in Germany, Switzerland and the Italian Alps, while ind ividuals from Slovakia and the Czech Republic come into separate group s of phenotypic similarity. Irish and British specimens are separated but highly related and Spanish populations show an unexpectedly high d istance from the remaining clusters.