Beetle identification can be tricky! We've compiled this information on some of our most commonly reported pests and other large beetles found in Hawai'i. If you aren't sure what you have found, take a photo or video and send it to the CRB Response at email@example.com or text 808-679-5244.
Oriental flower beetle larva (left) and coconut rhinoceros beetle larva (right).
Oriental flower beetle: Protaetia orientalis
Oriental flower beetle (OFB) is one of the most commonly mistaken look-alike species of the coconut rhinoceros beetle (CRB). OFB are Asian scarab beetles that have been established on O'ahu since 2002. Unlike CRB, OFB feed on overripe fruit, flower nectar, flower pollen, and sap from a variety of plants. They are a common widespread pest, with no control program. Although they seem to be a nuisance, their feeding does not appear to harm fruiting or flowering productivity, as they are opportunistic and will usually feed on fruit that has been injured (fallen or opened by birds). OFB is active during the day and cluster in larger groups around their feeding source (ripe fruit).
As adults, OFB reach ~1 inch. in length; much smaller than a CRB which can be over 2 inches. They do not have a horn but instead antennae on their small head capsule. OFB is a shiny metallic brown color with golden flecks that sparkle in the sunlight.
As larvae, OFB and CRB are difficult to distinguish. If you are having trouble, please reach out to us with the photo of the underside and a video of its crawling pattern. OFB will only reach ~2 inches in length, where CRB can be 3.5-4 inches in its 3rd larval instar (keep in mind that CRB may be ~2 inches at its 2nd larval instar). We look for a raster marking near their rear underside to identify OFB. OFB also crawl on their back (legs in the air) and curl into an "e" shape tucking their head into their abdomen when handled.
Black Dung Beetle: Copris spp
At first glance, dung beetles can look similar to CRB in that they are solid black and sometimes have an apparent horn. Dung beetles are significantly smaller than CRB reaching about 1.5 cm in length and have a rigid wing case.
Although dung beetles are not native, they are beneficial and were intentionally introduced to Hawai'i for the ranching and farming industry. As dung feeders, they are important to our ecosystem and have never been recorded damaging ornamental plants or crops.
Queensland longhorn beetle: Acalolepta aesthetica
The Queensland longhorn beetle or QLB is a large invasive beetle established on the East side of Hawai'i Island. QLB is a major pest to tropical crops and should be reported immediately if found. For more information visit: https://www.biisc.org/qlb/
Coconut rhinoceros beetle (CRB) are Scarabaeoidea in the family Scarabaeidae. There are no native cousins of the same family, but the native stag beetles of the family Lucanidae are important to mention. These flightless, endemic beetles are known from Kaua'i and are extremely rare. Native Hawaiian Stag Beetles, like many endemic species, suffer from habitat loss and predation or competition from introduced species.
There are two native longhorn beetles to Hawai'i. Aegolipton reflexum (family Cerambycidae), although not visually similar to CRB, is of a similar size and color and could be mistaken for it at a glance. Hawaiiandra puncticeps is another large endemic longhorn beetle. This beetle more closely resembles our native stag beetles.