Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 8, 1996
Publication Date: N/A
Interpretive Summary: The fall armyworm is an economically important pest of many crops in North and South America. Chemists and natural product scientists have shown an interest in exotic plant materials as sources of new chemicals for possible use in reducing losses in crops by insect pests. Dogwood, hydrangea, black cherry an Bradford pear leaves were fed to larvae of the fall armyworm to discover possible new chemicals that inhibit their growth and development. Fall armyworm tested as young larvae did not perform well after having fed on leaves of these nonhosts. When larger larvae were fed the leaf-diets, the results indicated that leaves of hydrangea possess a toxic factor and that leaves of the dogwood, black cherry and Bradford pear have a severe growth retardant for larvae of the fall armyworm. Thus, these nonhosts contain chemicals that offer a potential for extraction and identification for possible use in controlling larvae of the fall armyworm on crops.
Technical Abstract: Chemists and natural plant product scientists have shown an interest in exotic plant materials that are considered non-hosts to the fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith). Non-host plant species may serve as sources of materials that reduce the feeding and growth of herbivorous insects. Previous research indicates that FAW feeding deterrents occur in Dogwood, Cornus florida L., twigs and leaves; Hydrangea, Hydrangea macrophylla (Thunb.) Seringe, leaves; Black Cherry, Prunus serotina Ehrh., leaves; and Bradford Pear, Pyrus calleryna Decne, leaves. We report results of lab bioassays with neonate and 5th instar FAW fed a standard diet alone and amended with celufil or leaves from these plant materials. The results indicate that neonates had reduced growth and frass production when fed diets containing leaves of these plants. FAW 5th instars had reduced consumption and weight gain when fed the hydrangea leaf-diet. These results suggest a toxic component in the leaves of this plant that reduces the performance of the FAW neonates and 5th instars. The results also indicate that the leaves of dogwood, black cherry and Bradford pear have growth inhibitors present in their leaves that adversely affect the growth of neonate FAW.