If the average banana weevil borer counts from bait trapping are more than two per trap (subtropics) or more than four per trap (tropics), registered chemical treatments should be applied according to label directions. If average counts are less than these, treatment is not considered necessary. Pheromone trapping doesn’t currently have a threshold value.

When choosing a chemical, it is essential to consider the life stage and behaviour of the banana weevil borer. The adults typically move around corms during spring and autumn to feed and lay eggs. To achieve optimal control, it is recommended to apply chemicals during these peak activity periods, using banded or butt spray applications that apply insecticides adjacent and/or onto the plants . By comparison, injection treatments aim to control larvae within the corm and therefore may have more flexibility in when they can be applied. However, some of these chemicals should not be applied during the dry season, as these chemicals have shown an increased incidence of mite flares. Always check the product label for guidance.

Chemical options are generally older chemistries that are disruptive to integrated pest management and/or other insects present throughout blocks. When trying to control banana weevil borer, certain chemicals have been known to cause mite flares. Therefore, it is crucial to only use spray treatments when the infestation has reached critical levels. Insecticide resistance is a threat with current options available, so chemical choices and modes of action should be rotated to reduce the risk of resistance. Always check the APVMA website for current chemical registrations before use. All chemical applications should be made according to the directions on the label. Resistance management plans should be followed to reduce insecticide resistance risk, see CropLife plans here.