Abstract
Methanolic extracts of stems and roots of silver fern, Cheilanthes farinosa Kaulf., (Polypodiaceae: Pteridophyta) incorporated into a semi-synthetic diet significantly extended the larval period, reduced pupal weight and adversely affected pupation of the cotton bollworm, Helicoverpa armigera (Hubner) (Noctuidae: Lepidoptera). Early third instars were more susceptible to the treatment than late third instars. A steroidal fraction (Rf 0.7) from the methanolic extract significantly reduced mean larval weight but did not affect pupation. A major ecdysteroidal component (R.t. 9.233 min.) was purified by reverse phase HPLC of this fraction, along with two minor components. The total yield of ecdysteroids was 564 mg/kg of shade-dried root and stem matter. Pooled HPLC fractions, when injected into final instars, resulted in dose-dependent effects on larval-pupal transformation. Adults emerging from treated larvae failed to lay eggs and were shorter-lived than their untreated counterparts.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.