The profile of volatile compounds emitted by pepper plants, Capsicum annuum (Solanaceae), under individual or simultaneous attack by the bacterial leaf spot (BLS), Xanthomonas campestris pv. vesicatoria (pepper race 3) and by beet armyworms (BAW), Spodoptera exigua (Noctuidae) were compared. Emission of volatiles in all plants showed a diurnal pattern with peak release during the afternoon. Healthy pepper plants released comparatively small quantities of several volatile compounds. BAW-damaged plants released a broad array of compounds and this profile was quantitatively and qualitatively different from those of healthy, BLS- and BLS+BAW-damaged plants. Plants infected with BLS alone emitted E-2 hexenal, methyl salicylate, and tridecatetraene in quantities that were significantly greater than those present in healthy plants. BSL-infected peppers exposed to BAW-feeding emitted all the compounds present in profiles of peppers damaged by BAW alone, although in lower quantities, with the exception of tridecatetraene which was one of the most prominent compounds along with methyl salicylate in BLS-infected plants. Methyl salicylate was only present in emissions from plants that were infected with BLS.
Species 1: Lepidoptera Noctuidae Spodoptera exigua (beet armyworm)
Species 2: Solanaceae Capsicum annuum (bell pepper, sweet pepper)
Keywords: plant volatiles, plant-insect interaction
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA