Abstract
Encelia farinosa Gray (Asteraceae: Heliantheae), a common shrub of the Sonoran desert, contains both sesquiterpene lactones and chromenes. Chloroform extracts of E. farinosa leaves were deterrent to larvae of Heliothis zea (Boddie) in choice tests, but farinosin, a eudesmanolide sesquiterpene lactone from E. farinosa, was not. Five sesquiterpene lactones from different Asteraceous genera were examined for their effect on the relative growth rate (RGR) of H. zea at 0.1% fresh weight in an artificial diet. Only dchydroleucodin, a guaianolide sesquiterpene lactone from Artemisia tridentata spp. vaseyana, reduced growth. Three closely related chromenes (precocene 1 and 2 and encecalin) were examined for their effects on survivorship (SR) and RGR of H. zea at five different concentrations. Precocene 1 and 2 exhibited the greatest activity on survivorship and growth rates, whereas encecalin was less active.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
