Geographical variation in food plant selection of Eupithecia gelidata Möschler, 1860 (Lepidoptera, Geometridae)

The relict bog populations of Eupithecia gelidata Möschl. in South Bohemia are obligatorily associated with Ledum palustre L., which is here the dominant shrub, all Salix species being absent. In the subarctic and boreal populations of E. gelidata, altemative food plants are willows (Salix spp.). Under laboratory conditions, larvae of the Bohemian populations can accomplish their development feeding on Salix, but Ledum is clearly preferred. The larvae living on Ledum and Salix are usually differently coloured. Thus, in spite of the different food plants and coloration of the larvae, the species seems to be taxonomically homogeneous