This is a popular trap for monitoring Gypsy Moth and many other prominent insect pests including Diamondback Moths. Delta Traps use a sticky catch surface to capture pest insects. For some insects (e.g. Douglas fir tussock moth) fold entrance flaps out, "open option". Pheromone lures, specific for each target species, are easily installed. Long lasting, durable White Plastic Delta Traps with quick change inserts.