o:5824 Biological activity of essential oils of Calocedrus decurrens and Cupressus arizonica on Lymantria dispar larvae and Phytophthora root pathogens en A B S T R A C T Composition of Calocedrus decurrens and Cupressus arizonica essential oils (CDEO and CAEO, respectively), their antifeedant activity on spongy moth (Lymantria dispar) larvae, as well as their antimicrobial activity on three Phytophthora species were investigated. In leaves of these two conifers from the Cupressaceae family, monoterpenes strongly dominated (90.5 and 85.0%, respectively), but their terpene profiles were different. The dominant compound of CDEO was δ-3-carene (49.5%), followed by myrcene (9.4%), terpinolene (8.6%) and α-pinene (7.0%). In CAEO, the most dominant compounds were limonene (23.3%) and α-pinene (20.5%), followed by umbellulone (12.0%) and terpinen-4-ol (9.5%). CDEO showed a strong antifeedant activity, while leaf discs treated with CAEO had phagostimulatory effect on spongy moth larvae. CAEO had no significant effect on relative consumption and larval growth rate, while CDEO reduced consumption and stimulated growth at the lowest EO concentration (0.05%). Both EOs significantly affected the growth of colonies of the Phytophthora species tested. At concentrations of 0.5% and 1%, a 100% inhibition was observed in almost all experimental groups, with the exception of P. plurivora on 0.5% CDEO. At a concentration of 0.1% inhibition rate varied from 15% in P. ×cambivora treated with CDEO to 90% in P. quercina treated with CAEO. These findings indicate that these two EOs could be used to control tree pests. Keywords: Coniferous essential oils Spongy moth Antifeedant activity Larval growth Phytophthora species Antimicrobial activity 1552099 10.1016/j.indcrop.2024.118602 1552101 0926-6690 2024-10-25T11:35:20.503Z 44 yes 46 Slobodan D. Milanović 46 Ivan Lj. Milenković 46 Jelica M. Lazarević 46 Marina M. Todosijević 46 Jovana P. Ljujić 46 Zorica S. Mitić 46 Biljana M. Nikolić 0000-0002-2436-8294 46 Petar D. Marin 46 Vele V. Tešević application/pdf 2266982 https://unilib.phaidrabg.rs/o:5824 no yes 18 70 92000001 2024 71A07 Industrial Crops & Products 215 118602 Elsevier 2024