The use of aggregation pheromones for the management of weevil borers in cane fields

Abstract

Pheromone mass trapping of adult sugarcane weevil borer, Rhabdoscelus obscurus, was conducted during February-June 1999 in far-north Queensland using a combination of rhynchophorol/octanol, ethyl acetate and pieces of split cane. Though traps attracted large numbers of adult borers, treated plots had higher numbers of borers compared to control plots. Cane plants in pheromone treated plots experienced higher percentage of infested stalks and a higher proportion of damaged internodes compared to control plots. This work suggests a change in the trapping technique to prevent damage early in the season. More work is needed to investigate the potential of placing pheromone traps outside cane fields so that the number of adults is reduced in the neighbouring paddocks. Pheromone traps can also be placed in one block planted with a tolerant variety within the area of infestation, then an insecticide can be applied in the treated block targeting the adults that escaped getting trapped. The potential of using a pesticide along with pheromone trapping still however needs to be investigated.