GUSTATORY AND OLFACTORY RESPONSES OF CYLINDROCOPTURUS-ADSPERSUS (LECONTE) TO VARIOUS PLANT-SPECIES IN THE LABORATORY

Feeding preferences and olfactory responses of Cylindrocopturus adsper sus (LeConte) (Coleoptera:Curculionidae) to nine plant species were co mpared with sunflower, Helianthus annuus L. (Asteraceae), for stem wee vil feeding preference in the laboratory. Sunflower was strongly prefe rred in each assay. Six crop species were also assayed for stem weevil preference in the absence of sunflower. Although overall feeding was diminished, C. adspersus showed a measurable feeding response to sever al plant species unrelated to its host plant. In olfactory assays, ste m weevils preferred sunflower leaf discs to blank controls, but showed no preference for sunflower stems to blank controls. However, when as sayed together, sunflower stems elicited a greater olfactory response than did sunflower leaf discs. Possible explanations regarding the gus tatory and olfactory responses of C. adspersus are discussed, as is th e potential for employing phytochemical stimuli as baits for incorpora tion into a pest monitoring program.