Insecticidal effects of extracts from two rice varieties to brown planthopper, Nilaparvata lugens

Citation
Gr. Zhang et al., Insecticidal effects of extracts from two rice varieties to brown planthopper, Nilaparvata lugens, J CHEM ECOL, 25(8), 1999, pp. 1843-1853
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
JOURNAL OF CHEMICAL ECOLOGY
ISSN journal
0098-0331 → ACNP
Volume
25
Issue
8
Year of publication
1999
Pages
1843 - 1853
Database
ISI
SICI code
0098-0331(199908)25:8<1843:IEOEFT>2.0.ZU;2-W
Abstract
Ether extracts from a resistant rice variety, Jingxian 89, and a susceptibl e variety, Qidaizhan, were significantly toxic to Nilaparvata lugens adult females, causing 98% and 73.5% mortalities, respectively. The area covered honeydew droplets excreted by N. lugens adult females while feeding on Qida izhan was 28.5-fold more than the area of those feeding on the resistant va riety, Jingxian 89. The honeydew covered areas were reduced 29.7- and 8.8-f old, respectively, after feeding on plants treated with the ether extracts from both varieties. Among the fractions from each variety, fractions 9 (th ree sterols) from both varieties and fraction 10 (3-nitraphthalic acid) fro m Jingxian 89 showed significant repellent effects on the planthoppers. Fur ther bioassays revealed that fraction 9 from extracts of both varieties at 0.02 mg/ml or higher deterred the feeding activity of the planthoppers, whe reas the deterrent effects of fraction 10 from the extract of Jingxian 89 w ere 100- to 500-fold stronger than those of fraction 9. Fraction 10, identi fied as S-nitraphthalic acid, unique in Jingxian 89, was extremely toxic to N. lugens adult females, and the LC50 and LC90 were 0.00045 and 0.00525 mg /ml, respectively. After extensive bioassays and analysis, we concluded tha t 3-nitraphthalic acid plays a key role in the resistance to N. lugens adul t females.