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Feeding response of adult Helicoverpa zea (Lepidoptera:Noctuidae) to commercial phagostimulants

Lopez, J.D. Jr., Lingren, P.D.
Journal of economic entomology 1994 v.87 no.6 pp. 1653-1658
nutrition, Helicoverpa zea, phagostimulants, sucrose
Six commercial phagostimulants (Coax, Entice, Gusto, Konsume, Mo-Bait, and Pheast) at the lowest recommended field rates were compared to deionized water and 5% source (wt:vol) in water relative to proboscis extension response, feeding time and feeding volume of 1-, 2-, and 3-d-old unfed laboratory-reared male and female adult corn earworms, Helicoverpa zea (Boddie). The percentage of 1-d-old females and males showing a positive proboscis extension response upon tarsal contact was significantly higher for 5% sucrose than for the other treatments which were not significantly different. There were no significant differences in the percentages of positive proboscis extension response of 2-d-old females and males to all treatments or to 5% sucrose after initial exposure to the phagostimulants and water, indicating an increase in responsiveness as nonspecific hunger or thirst increased. With few exceptions, notably the 3-d-old females for feeding time, and no exceptions for feeding volume, no significant differences were observed between the response to commercial phagostimulants and deionized water alone; but responses to all these treatments were significantly lower than responses to 5% sucrose. Feeding time and feeding volume of the same moths on 5% sucrose after initial feeding on the commercial phagostimulants and water were considerable. Overall, these results indicate that the commercial phagostimulants are not effective feeding stimulants at the rates evaluated for adult H. zea when compared with 5% sucrose because the feeding response was equal to that of water alone. Some implications of the results relative to the use of feeding stimulants in adult H. zea control are discussed.