The larva is the immature form of an insect between the egg and pupa stages. For scarab beetles (beetles in the family Scarabaeidae), their larvae are white and are often referred to as white grubs. In Hawaiʻi, there are no native scarab beetles, and identifying the white grubs can be difficult because they can look so similar. But don't fear! We've created an easy-to-use identification key to help.
CRB don't always look like a beetle. They start their lifecycle as an egg the size of half a grain of rice. They emerge and grow through 3 larval stages before pupating. Each larval instar is classified by the size of its head capsule. Since larvae can be anywhere from the size of an egg to 3.5-4 inches at their largest, using size as an identifying factor doesn't always work.
This key is designed to help guide you in your larvae identification pursuit! Click the download icon below and print a copy for yourself to use in the field. If you're having difficulty, don't hesitate to snap a photo and send it to the CRB Response for help.