A key insect pest is one that often triggers the first insecticidal treatments in a field, and the three-cornered alfalfa hopper (TCAH) apparently has reached that status in peanuts. 

The first insecticide treatments then influence other pest activities the remainder of the season.

Specifically, in this situation, treatment for TCAH eliminates beneficial insects and allows an opportunity for caterpillar pests to build in fields. Some of us call this the “caterpillar hampster wheel.” Once you get on, you can’t get off.

See more at  http://flacrops.com/.