FEEDING RESPONSE OF ADULT HELICOVERPA-ZEA (LEPIDOPTERA, NOCTUIDAE) TOCOMMERCIAL PHAGOSTIMULANTS

Six commercial phagostimulants (Coax, Entice,:Gusto, Konsume, Mo-Bait, and Pheast) at the lowest recommended field rates were compared to de ionized water and 5% source (wt:vol) in water relative to proboscis ex tension response, feeding time and feeding volume of 1-, 2-, and 3-d-o ld unfed laboratory-reared male and female adult corn earworms, Helico verpa tea (Boddie). The percentage of 1-d-old females and males showin g a positive proboscis extension response upon tarsal contact was sign ificantly higher for 5% sucrose than for the other treatments which we re 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 ex posure to the phagostimulants and water, indicating an increase in res ponsiveness as nonspecific hunger or thirst increased. With few except ions, notably the 3-d-old females for feeding time, and no exceptions for feeding volume, no significant differences were observed between t he response to commercial phagostimulants and deionized water alone; b ut responses to all these treatments were significantly lower than res ponses to 5% sucrose. Feeding time and feeding volume of the same moth s on 5% sucrose after initial feeding on the commercial phagostimulant s and water were considerable. Overall, these results indicate that th e commercial phagostimulants are not effective feeding stimulants at t he rates evaluated for adult H. tea when compared with 5% sucrose beca use the feeding response was equal to that of water alone. Some implic ations of the results relative to the use of feeding stimulants in adu lt H. tea control are discussed.