Geographic differentiation between populations of Rhinocyllus conicus Frölich (Coleoptera: Curculionidae): concordance of allozyme and morphometric analysis

The weevil Rhinocyllu conicus develops only in the flowerheads of thistles {Asteracea; Carduineae) and therefore it is used as a biocontrol agent against thistle weed species. Populations out of 14 regions within its natural distribution area (from the Atlantic coast in the west to Israel in the east) were analysed by means of allozymes and morphometries. In both analyses the 14 populations were grouped into two concordant units. Based on nine scored loci (six of them polymorphic), mean Nei's genetic distance between the two groups was 0.073. In a reclassification test following DFA of morphometric data, 93.2% of all individuals were grouped back into the correct group. The two groups were considered to belong to a temperate and a Mediterranean subspecies respectively, the latter probably identical to the formerly described Rhinocyllus oblongus .