How to control and manage the Cylas formicarius (Sweet Potato Weevil)

Time of Trapping

It is best to place lures and traps for the first time when the pests are at low density to lower loss, or at least 1 month before harvest and maintain traps between cropping cycles. Trapping during the post harvest period is important. During the post harvest period many males emerge from drying plants and the soil and their capture lowers pest pressure for the next crop cycle.

Trap selection

The bucket funnel trap is most sensitive trap to use for monitoring Sweet Potato Weevil.

Trap density

For detection surveys, place 1-2 traps in each [high risk] area.

For mass trapping 75-120 traps per hectare would be needed depending on plant situation.

Peripheral dense, thin in the middle. Pay attention to the wind direction. Put more at the place where wind come from.

Trap position

Put the traps 15cm above from the plant. 

Peripheral dense, thin in the middle.

Lures: Lures can be changed every 4-6 weeks to get the most accurate results.

Lures handling 

Pheromone lures are very sensitive tool. They can be affected by exposure to elevated heat and direct sunshine. Direct touching by hand may cause cross contamination leading to mixed catches in the trap. Some contaminants such as Nicotine may have repellent effect reducing trap catch.

Lure storage

In cool dry place, the shelf life is 12 months.

In refrigerator under -5~-15 degree, the shelf life is 24 months up.