"Sink glass jars into the soil. Fill to the halfway point wit a mixture of 10 parts water to 1 part of molasses. The hoppers are drawn to the sweet smell of the molasses, they dive in and drown. Clean traps as needed."
Guess that is similar to the way a beer trap works for slugs?
Sunset Zone 28, AHS Heat Zone 9, USDA zone 8b~"Leaf of Faith"