Systemic activity of plant extracts in Cedrela odorata (Meliaceae) seedlings and their biological activity on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae

1 Deterrent and toxic substances known to affect Hypsipyla grandella larvae were bioassayed to determine their possible systemic activity under laboratory conditions in Turrialba, Costa Rica. 2 Leaflets from Spanish cedar Cedrela odorata seedlings grown in vitro on culture media treated with different plant extracts were excised from the seedlings and exposed to H. grandella larvae. 3 Both Azatin EC (derived from neem, Azadirachta indica) and plant extracts (from Quassia amara wood, Ruta chalepensis leaves and Sechium pittieri fruits) were able to translocate within Spanish cedar seedlings and express their biological activity against H. grandella larvae. 4 Rates of leaflet consumption were nil for seedlings treated with the commercial standard (carbofuran) and Azatin EC, both causing larval death. 5 Intermediate levels of consumption were reached with the three plant extracts, all of them causing deterrence, because they precluded feeding activity by larvae when exposed to treated leaflets.