Although a major pest of woody ornamentals in commercial nurseries, they cause occasional injury in greenhouses where Taxus plants are being propagated by both adults and larvae. Beetles can crawl into houses and other structures, causing alarm by homeowners. They are black, shiny, without scales and with coarse, strial punctures on the wing covers. Adults are common on fruit trees in June. It has not been a serious pest of strawberries in Ohio, but may occasionally enter residences for hibernation.
Adults feed at night and hide during the day.
No males have been found. They may crawl throughout the house from baseboard to the ceiling, dropping to the carpet and repeating the process. They hide in clothing, bedding, carpet or appear in sinks, bathtubs, drains and other places where moisture is present. Outdoors, adults feed on leaves and larvae on plant roots and between them both, injure, weaken and sometimes kill the plants. Larvae especially injure roots of hemlock, spruce, Taxus and arborvitae in nurseries and plantations.