02120nas a2200157   4500008004100000020001400041245016000055210006900215260001200284300001400296490001100310520143900321100002401760700001601784856016201800       2001                        eng d  a0021-856100aAcute, sublethal, antifeedant, and synergistic effects of monoterpenoid essential oil compounds on the tobacco cutworm, Spodoptera litura (Lep., Noctuidae)0 aAcute sublethal antifeedant and synergistic effects of monoterpe  c2001///  a715 - 7200 v49; 493 aMonoterpenoids (terpenes and biogenically related phenols) commonly found in plant essential oils were tested for acute toxicity via topical application to tobacco cutworms (Spodoptera litura Fab.). The most toxic among 10 such compounds was thymol (LD(50) = 25.4 microg/larva) from garden thyme, Thymus vulgaris. The compounds were then tested for sublethal effects, specifically inhibition of larval growth after topical application of low doses. Among 6 compounds tested, an LD(10) dose reduced growth by 20% on average 3 days after administration. Feeding deterrence was determined using a cabbage leaf disk choice test. The most deterrent compound was thymol, with a DC(50) of 85.6 microg/cm(2) leaf disk area. Because minor constituents in complex essential oils have been suggested to act as synergists, binary mixtures of the compounds were tested for synergy vis à vis acute toxicity and feeding deterrence. trans-Anethole acted synergistically with thymol, citronellal, and alpha-terpineol, in terms of both acute toxicity and feeding deterrence. On the basis of these findings, several complex mixtures were developed and tested as leads for effective control agents. Candidate mixtures demonstrated good synergistic effects. The observed LD(50) of mixture 3 was 40.6 microg/larvae compared to an expected value of 74.6 microg/larvae. The result of this research is a proprietary product suitable for commercial production1 aHummelbrunner, L, A1 aIsman, M, B  uhttp://muse.lib.auth.gr:9797/com/csa/?MuseHost=www-mi2.csa.com&MuseFirst=1&id=2&recnum=6&SID=b8599c660c0d7abb640bacacd8dd54da&MusePath=/ids70/view_record.php