Larvicidal and Oviposition Deterrent Effects of the Jimsonweed (Datura stramonium) Extracts on the Diamondback Moth, Plutella xylostella

The importance of the diamondback moth, Plutella xylostella (L.), has dramatically risen mainly due to the overuse of broad-spectrum insecticides, which has resulted in increased selection for pesticide resistance, destruction of natural enemies, and pest resurgence. These issues accompanied by increasing insecticide residue on crops have created an urgent need for more sustainable strategies for P. xylostella management. The present study examined the efficacy of extracts from different parts of the jimsonweed, Datura stramonium L., as larvicide and oviposition deterrent on P. xylostella larvae and adults, respectively. Bioassays revealed higher toxicity (LC۵۰ and LC۹۰) of flower (۸۲.۳ and ۱,۴۷۵.۴ mg L-۱), seed (۱۴۶.۸ and ۴,۸۲۸.۷ mg L-۱) and root (۱۶۵.۳ and ۳,۴۹۳.۸ mg L-۱) extracts of D. stramonium compared with leaf (۵۲۶.۶ and ۲۹,۳۵۲.۱ mg L-۱) and stem (۸۴۱.۴ and ۱۳۶,۲۴۸.۱ mg L-۱) extracts. In addition, flower extract showed the greatest toxicity between the extracts based on LC۵۰ dose ratio (۰.۵۶۱, ۰.۴۹۸, ۰.۱۵۶ and ۰.۰۹۸) and LC۹۰ dose ratio (۰.۳۰۶, ۰.۴۲۲, ۰.۰۵۰ and ۰.۰۱۱) when compared with seed, root, leaf and stem extract, respectively. Furthermore, oviposition deterrence tests using sublethal doses exhibited that the highest oviposition inhibition was provoked by flower extract of D. stramonium (۶۳.۰%) compared with root (۴۶.۰%), seed (۴۳.۸%), stem (۳۳.۷%), and leaf (۲۸.۳%) extracts. Results indicated that jimsonweed extracts could be used as an effective pesticide and oviposition deterrent against P. xylostella. Possibilities for application of D. stramonium extracts in pest management and for developing a botanical insecticide or an oviposition deterrent in context of sustainable pest management are discussed.

Keywords:

Botanical pesticides , Cruciferae , Pest management , Plant extract.