Large Miller Moth Population Expected by Mary Small

Euxoa auxiliaris Miller Moth

According to CSU Extension Entomologist, Dr. Whitney Cranshaw, “miller moth” numbers will be above average. Because the numbers of their caterpillars found in crops and other locations this spring, the moth numbers may be way above average. 

How much of a nuisance they will be is dependent on moisture and numbers of flowering plants around. Moisture has been good, contributing to the development of flowering plants. While last week’s freeze may have damaged some flowers, they are still abundant and will be attractive to the moths. Moths feed on nectar in the flowers.

Flowering plants most often visited by miller moths in our area include lilac, cherries, spirea, cotoneaster, horse chestnut, raspberry and Russian olive. Dark and dense plants such as cotoneaster, spruce and pines are most used by miller moths for shelter around homes.

The moths become a problem for humans when they accidentally enter homes.  During the day moths seek shelter in cracks and crevices around homes, in door entries and near windows.  At night, the moths become active and may be attracted to indoor or exterior lighting.

The major infestation is not expected for a few more weeks, about mid-June.
For detailed information on miller moths, including deterring them from your home, see this information.