Glandular trichome extracts from Medicago sativa deter settling by the potato leafhopper Empoasca fabae

• Published in: Journal of chemical ecology 2004-05, Vol.30 (5), p.927-943
• Main Authors: Ranger, C.M, Backus, E.A, Winter, R.E.K, Rottinghaus, G.E, Ellersieck, M.R, Johnson, D.W
• Format: Article
• Language: English
• Subjects: Alfalfa; Amides; Amides - analysis; Amides - metabolism; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Bioassays; Biological and medical sciences; Biological Assay; Chloroform; Chromatography, Gas; Cicadellidae; Cultivars; dose response; Empoasca fabae; Ethanol; Fabaceae; Fatty Acids - analysis; Fatty Acids - metabolism; Fundamental and applied biological sciences. Psychology; Gas chromatography; Hemiptera - drug effects; Hemiptera - physiology; host seeking; insect pests; Mass Spectrometry; Medicago sativa; Medicago sativa - chemistry; Pest Control, Biological - methods; pest resistance; plant extracts; Plant Extracts - pharmacology; Plant Leaves - chemistry; Plant Stems - chemistry; Population Density; Potatoes; Protozoa. Invertebrata; Settling behavior; Solanum tuberosum - parasitology; Solvents; Solvents - chemistry; Time; trichomes
• ISSN: 0098-0331; 1573-1561
• DOI: 10.1023/B:JOEC.0000028459.45035.90

Extracts of glandular trichomes from Medicago sativa were tested for their ability to disrupt the settling behavior of the potato leafhopper, Empoasca fabae. Erect and procumbent glandular trichomes were mechanically isolated from stem sections of resistant genotype "G98A," and nonglandular trichomes were collected from susceptible cultivar "Ranger." Isolated trichomes were extracted with chloroform, acetone, and ethanol, and the resulting crude extracts were applied to the surface of a sachet containing an artificial diet. Leafhoppers were offered a two-way choice between crude trichome extracts from G98A and Ranger. All three of G98A solvent extracts caused various degrees of diet rejection, resulting in the crude Ranger trichome extracts being preferred over G98A extracts. Overall, the fewest leafhoppers settled on the ethanolic extracts. Additional bioassays documented a dose response associated with G98A ethanolic extracts when compared with Ranger trichome extracts and a solvent control. No difference in preference behavior was detected between Ranger trichome extracts and a solvent control. Gas chromatography-mass spectrometry analysis revealed a homologous series of nonvolatile fatty acid amides C(n)H(2n+1) NO (n = 19-23) unique to G98A glandular trichome extracts.