EVALUATION OF A TRACTOR-PROPELLED VACUUM DEVICE FOR MANAGEMENT OF TARNISHED PLANT BUG (HETEROPTERA, MIRIDAE) POPULATIONS IN STRAWBERRY PLANTATIONS

In 1990 and 1991 the Biovac, a tractor-propelled vacuum device, was te sted to control tarnished plant bug, Lygus lineolaris (Palisot de Beau vois), populations in a strawberry ('Bounty') plantation located at St e-Anne de la Perade, Quebec, Canada. Two treatments were made in a com plete randomized design comprising four replicates: (1) Biovac treatme nts and (2) control plots (water only). Tarnished plant bug population s were assessed weekly by the saucer pot method. Treatments were done when tarnished plant bug populations exceeded 12 nymphs + adults per 1 00 taps in the four replicates. Tarnished plant bug populations exceed ed the action thresholds six and nine times in 1990 and 1991, respecti vely. After vacuum treatments, significant tarnished plant bug populat ion reductions occurred 7 times out of 15. On three occasions, populat ions levels were reduced, but not significantly. Failures occurred 5 t imes out of 15 occasions. There were no significant differences in the percentage of berries attacked by the tarnished plant hug. The use of vacuum devices is discussed in an integrated pest management context.