Carvone and less volatile analogues as repellent and deterrent antifeedants against the pine weevil, Hylobius abietis

摘要: :  The monoterpenoid carvone (1) has been shown to have strong antifeedant effects on Hylobius spp. However, because of the high volatility carvone, long-time protection conifer seedlings in field using this compound not possible. We demonstrate, several bioassay steps, that less-volatile, heavier analogues retain their pre-ingestive feeding inhibition activity large pine weevil, abietis (L.) for a longer time. first step evaluation biological 12 was micro-assay, choice test lasting 4 h. Compounds active at 100 nmol/cm2 were further dose–response tested give effective dose needed inhibit by 50% (ED50). Of 14 compounds tested, including both enantiomers, seven low doses (had ED50 values). As expected from lower vapour pressure compared with proved more resistant evaporation before testing. Thus, whereas effect 8-hydroxy-p-menth-en-6-one 4 declined after 2 days, some molar masses, such as alkylhydroxymenthenones 6 and 8, retained stable 4 days. 4 days strongly correlated molecular mass boiling point. When natural material (host Pinus sylvestris L. twig sections 48 h), showed rather activity. Probably, volatile is due repellent (olfactory mode) than deterrent (gustatory compounds. In agreement relatively twigs laboratory, hydroxymenthenone when 2 months 1 : 9 mixture polar wax.