White grubs are general names for larvae of several species of beetles. Some of the more important white grubs in nurseries include the Japanese beetle, green June beetle, May beetle, European chafer, Oriental beetle, Asiatic garden beetle and rose chafer.
Larvae are C–shaped and have three pairs of legs. The larvae can be quite large, about 1–2 inches when fully developed. The larvae damage plants by feeding on plant roots. Some (e.g. Japanese beetle) are quarantine pests, requiring special treatment before plants can be shipped. The adults of some species feed during the day, others feed at night – usually on leaves and flowers.
White grub larvae develop in the soil. There usually is one generation per year, but some species (e.g. May–June beetles) have two year larval development cycles where adults emerge every three years. Adult emergence is in the spring and summer. After mating, eggs are deposited in/on the soil, and larvae move down into the soil to feed following egg hatch. |