Journal of Chemical Ecology (1995) 21, 1255-1270

Azucena Gonzalez-Coloma, Matias Reina, Raimundo Cabrera, Pedro Castañera and Carmen Gutierrez (1995)
Antifeedant and toxic effects of sesquiterpenes from Senecio palmensis to colorado potato beetle
Journal of Chemical Ecology 21 (9), 1255-1270
Abstract: A bioassay-guided fractionation of the aerial parts of Senecio palmensis resulted in the isolation of two sesquiterpenes, 2,10-bisaboladien-1-one and 11 ß- acetoxy-5-angeloyloxy-silphinen-3-one. The bisabolene and the silphinene represented 0.012% and 0.024% of the plant dry weight, respectively. Both compounds showed antifeedant activity against Leptinotarsa decemlineata larvae and adults in short-term choice and no-choice bioassays. Both compounds were also tested against different species of phytopathogenic fungi. The beetles were more sensitive to these compounds in choice than in no-choice assays, with a gradient of increasing sensitivity from second instars to adults. Bisabolene was 45 times less active as an antifeedant than juglone, which was tested as a positive control. The silphinen was more active than the bisabolene, with a range of activity similar to juglone. Furthermore, exposure of fourth instars to these compounds over a 24-hr period resulted in reduced feeding and growth rates. To distinguish between antifeedant and toxic effects, growth efficiencies were calculated as the slope of the regression of relative growth rate on relative consumption rate. The comparison of these results with those of antifeedant simulation and contact toxicity bioassays indicates that feeding inhibition is the primary mode of action of the bisabolene, while the silphinene shows both antifeedant and toxic effects.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Pedro Castañera, Azucena González-Coloma

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Leptinotarsa decemlineata