Leaf-surface extracts of Nicotiana gossei Domin, N. benthamiana Domin, and N. bigelovii (Torrey) Watson were the most active of those from 17 species of Nicotiana evaluated against late second/early third instars of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood). Four chromatographically purified sucrose esters of N. gossei resulted in 88-94% mortality of late second/early third instars of the sweetpotato whitefly, Bemisia tabaci (Gennadius). A less purified mixture of the four compounds was effective at 1.0 mg/ml (wt:vol) against nymphs of both whitefly species and the green peach aphid, Myzus persicae (Sulzer), and it deterred feeding and oviposition by the twospotted spider mite, Tetranychus urlicae Koch. These sucrose esters were not active against whitefly eggs; neonates of the Colorado potato beetle, Leptinotarsa decemlineata (Say); or second instars of the western flower thrips, Frankliniella occidentalis (Pergande). The selective activity against immature insects, and the feeding and ovipositional deterrence to spider mites suggest pesticidal activity. Activity of 1.0 mglml (wt:vol) aqueous mixtures of the four compounds was comparable with, or better than, label rates of currently available biorational products or pesticides. The purified product was stable for 1 yr.
Document Type: Research Article
Publication date: December 1, 1994
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.