PROBOSCIS EXTENSION RESPONSE OF ADULT HELICOVERPA-ZEA (LEPIDOPTERA, NOCTUIDAE) TO DRY SUGARS

Dry sugars were evaluated for their potential as feeding stimulants fo r the adult corn earworm, Helicoverpa tea (Boddie). The current study is part of an intensive effort to use adult feeding stimulants or attr actants in programs to manage populations of H. tea on crops or on an areawide basis. Sucrose, fructose, glucose, and Various other commerci al sugarcane products (brown, powdered, and granulated sugars) along w ith raw sugar crystals were evaluated for their ability to elicit prob oscis extension, a response essential for feeding, from laboratory-rea red males and females and wild males captured in sex pheromone traps. We found that the particle size of sucrose was important in eliciting proboscis extension, and that ground sucrose and fructose were more st imulating than glucose. The most stimulating sugarcane product was pow dered sugar and the response to it was similar to that found with grou nd sucrose and fructose. Laboratory-reared males and females were more responsive to small particles of sucrose, fructose, and powdered suga r than wild males captured in traps baited with sex pheromone. These r esults raise concerns about the use of laboratory-reared moths for ass essing field adult feeding behavior. Although the low response of wild males to dry sugars raises some questions about the potential of thes e materials for use as feeding stimulants in management programs, more work is needed to gain a better understanding of the sensory mechanis ms involved in the proboscis extension response to dry sugar particles and the conditions under which these particles elicit a feeding respo nse.