CRB found in Waimanalo

On July 19th, 2018 an adult female coconut rhinoceros beetle (CRB) was found in Waimanalo. This is the first detection on Oahu’s east side since the beetle arrived on the island in December 2013. There are no other signs of beetles establishing themselves in the area and more traps have been deployed to aid in monitoring. The Hawaii Department of Agriculture biological control section chief, Darcy Oishi, says it’s likely the beetle hitchhiked to the area.

Coconut rhinoceros beetles breed in mulch and green waste piles. Adult beetles feed not only on coconut trees, but also date palms, pineapple, taro, sugar cane, papaya, hala and native loulu palms. It’s recommended to inspect mulch and green waste piles regularly and report any suspect CRB grubs, adults or suspected damage to CRB Response at 679-5244 or email BeetleBustersHI@gmail.com.

CRB is the largest beetle on Oahu….about the size of your thumb. It is nocturnal, unlike the Oriental Flower Beetle which are active in the day. Oriental Flower beetles are much smaller, have no horn and are mottled with fleck of gold or white. The dung beetle if often thought of as a baby CRB, but not the case…baby CRB are grubs.

CRB damage on leaves results in angular “v-cuts” in the leaves.

Bore holes at the base of palm frond.

Bore holes made by adult CRB

Bore hole made by adult CRB.

Various life stages (instars) and sizes of the CRB larvae

Videos: Larvae movement; CRB grub vs. Oriental Flower Beetle grub