Sesquiterpenes from the Senecioneae and their effect on food choice of the specialised leaf beetles Oreina cacaliae, Oreina speciosissima and the generalist snail Arianta arbustorum

The occurrence of sesquiterpenes of the furanoere-mophilane type (hereafter STs) in plants of the tribe Senecioneae (Asteraceae) has been known since the sixties (see Seaman, 1982 and references therein). They have been investigated in different plants of this tribe and there found to be reliable systematic traits (Toman et al., 1968). Other major groups of secondary chemicals such as pyrrolizidine alkaloids and benzo-furans also occur frequently in the Senecioneae.