RESPONSES OF LARVAL CHORISTONEURA-ROSACEANA (HARRIS) (LEPIDOPTERA, TORTRICIDAE) TO A FEEDING STIMULANT

The commercial feeding stimulant Pheast(R) was tested in the laborator y to determine its attractive and phagostimulatory effects on larval C horistoneura rosacenna (Harris). In choice experiments, larvae were at tracted initially to filter paper discs treated with Pheast, but did n ot remain on or near treated discs. Larvae were not attracted initiall y to raspberry leaf discs treated with Pheast, but were more likely to star near treated leaf discs than water-dipped ones. Larvae were neit her attracted to nor arrested on whole raspberry leaves treated with P heast. In no-choice experiments, larvae fed Pheast-treated leaves cons umed more leaf tissue than, and grew almost twice as quickly as, larva e fed leaves dipped in water. When larvae were fed leaves treated with Dipel WP (Bacillus thuringiensis var. kurstaki) plus 5% Pheast, the m ortality was 93% greater than that of larvae fed leaves treated with D ipel WP alone. These results suggest that Pheast has potential to enha nce efficacy of B. thuringiensis against C. rosaceana on raspberries i n the field.