Any of various large North American scarabaeid beetles of the subfamily Melolonthinae, appearing in late spring and having larvae that are destructive to vegetation. Also called June bug, May beetle. or May beetle or June bug Any insect of the genus Phyllophaga, belonging to a widely distributed, plant-feeding scarab beetle subfamily (Melolonthinae). These red-brown beetles commonly appear in the Northern Hemisphere on warm spring evenings and are attracted to lights. Heavy-bodied, they are 0.5-1 in. (1.2-2.5 cm) long and have shiny wing covers. They feed on foliage and flowers at night, sometimes causing considerable damage. The larvae live in the soil, and can destroy crops and kill lawns and pastures by severing the grasses from their roots; they are considered excellent fish bait