Effect of Clerodane-Type Diterpenoids Isolated from Salvia spp. on the Feeding Behaviour of Spodoptera littoralis

Twenty-nine clerodane-type diterpenoids isolated from species of Salvia growing in Mexico, or analogues of them, were tested for antifeedant activity against Spodoptera littoralis larvae using behavioural and electrophysiological bioassays. Eight of the compounds showed potent antifeedant activity in choice and no-choice bioassays and these compounds also stimulated dose-dependent responses from neurones in the lateral styloconic sensilla of S. littoralis.