Lindgren Funnel Traps

Lindgren funnel traps are a series of black funnels suspended one on top of the other from a branch or rope between two trees. At the bottom of the funnels a container with ethanol or ethanol/propylene glycol mix is placed (or some other preservative). These traps can also be baited with various bark beetle pheromones or with turpentine. They apparently mimic standing trees and wood boring beetles are attracted to them. The smell of the ethanol also helps attract the beetles. Various other insects end up in the samples as well. Generally, traps should be checked every couple of days if possible, and no less than once weekly.