Other related sap beetles are smaller and brown. The picnic beetles overwinter as adults in many types of plant cover near the soil surface. Once temperatures reach 60 to 65 degreesF in the spring, they become active and feed on fungi, pollen, or sap from many kinds of plants. They lay eggs in old corn ears or other decaying matter. Larvae develop in decomposing plant material, then pupate in the soil.
New adults emerge in midsummer.
There is one generation per year. Keep berries off the ground, and practice frequent, complete picking. Remove overripe and damaged berries, and bury culled berries. Because picnic beetles are attracted to overripe fruit, infestations usually build up after harvests are underway, and the use of insecticides is precluded by a combination of frequent picking and required preharvest intervals. Ripe berries are destroyed by Japanese beetles and green June beetles.