Four botanical extracts are toxic to the hispine beetle, brontispa longissima, in laboratory and semifield trials

Abstract

The potential of botanical extracts such as Celosia argenea L. (Caryophyllales: Amaranthaceae), Ricinus communis L. (Malpighiales: Euphorbiaceae), Mikania micrantha Humboldt, Bonpland & Kunth (Astrales: Asteraceae), and Catharanthus roseus (L.) G. Don (Gentianales: Apocynaceae) for the control of Brontispa longissima Gestro was evaluated in a bioassay and semifield trial. Doseresponse bioassay showed no significant difference in oraltoxicity among the extracts of C. argenea, M. micrantha, and C. roseus to larvae and adult of B. longissima. All extracts tested decreased the hatchability of B. longissima eggs. In particular, the extract of M. micrantha showed higher activity than others at the concentration of 5 mg/mL. In an antifeedant bioassay, the extract of C. argenea showed higher activity against the 1st larvae than that of other extracts (AF50 0.03 mg/mL), and C. roseus showed higher antifeedant activity to the 2nd to 5 th larvae and adult of B. longissima (AF50 0.34, 0.33, 0.11, 0.43, and 0.20 mg/mL, respectively). The semifield trial indicated that all extracts used in this study might reduce the pest population. Extracts of C. argenea and M. micrantha showed higher activities than that of C. roseus and R communis, and the decrease in population was 75.56% and 80.00% (without Abbott's correction) after seven days of treatment, respectively, at a concentration of 20 mg/mL. Therefore, these active botanical extracts may possess potential for use in control of B. longissima. © Copyright: This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.