How To Get Rid Of Miller Moths

What's not to love about Colorado summers... the miller moths! Every year these dusty annoying creatures invade Colorado homes and businesses. Why? Well, let's discuss. 

What exactly are miller moths?

The miller moth, common in Colorado and adjacent states, is the adult stage of the army cutworm. The caterpillar stage of the army cutworm feeds on crops and garden plants in winter and early spring. The adult form of the army cutworm feeds on nectar in late spring through early fall. 

Why are moths invading my property?

During warm summer months the moths migrate to higher elevations as they seek flowering plants. Areas close to the mountains like us fortunate ones in Fort Collins, Loveland, Windsor and the rest of the Front Range, see an abundance of these pests as they make their way. Miller moths avoid daylight and seek shelter before day break. Ideally, a daytime shelter is dark and tight. Small cracks in the doorways of homes, garages, and cars make perfect hiding spots. Often moths may be found clustered together in particularly favorable sites. Since cracks often continue into the living space of a home (or a garage, car, etc.) a ‘wrong’ turn may lead them indoors. At night, the moths emerge from the daytime shelters to resume their migratory flights and feed. Moths are attracted to white light, and therefore any light they happen to stumble across on their way to the mountains - like your kitchen light.

What can I do to get rid of miller moths?

Once inside, the best way to remove the moths is to swat or vacuum them, or attract them to traps. An easy trap to make is to suspend a light bulb over a bucket partially filled with soapy water. Moths attracted to the light often will fall into the water and be killed. (If this is attempted some wetting agent, such as soap or detergent, must be added or many moths will escape. Also, there are obvious dangers when bringing water and electrical equipment in close proximity and great care should be given to the situation. This includes use of a GFI receptacle for safety.)

What can a pest control company do to get rid of miller moths?

Unfortunately, not much. Insecticides have little or no place in controlling millers because the moths are not very susceptible to insecticides due to the makeup of their waxy body makeup. Also, any moths killed will likely be quickly replaced by new ones migrating into the area nightly.

That said, we may be able to help mitigate the number of moths entering your property by identifying and sealing areas where they might enter. Also, we can provide products for our commercial clients to aid in knock down. Residual applications of product can also have some effect on millers, but elimination is not possible. 

Please visit the Colorado State University Extension Office for more information on miller moths here:  https://extension.colostate.edu/topic-areas/insects/miller-moths-5-597