Beetlejuice Oriental Flower Beetle

The oriental flower beetle, Proteatia orientalis. Photo: Jeanne Lindgren

Hailing from China, Korea, and Japan, the oriental flower beetle, Proteatia orientalis, is a hefty beetle, about the size of my upper thumb. Its attractive bronzy metallic sheen is splotched with white markings, and gives a hint that it is in the family of Scarab beetles, many of which sport metallic colors. It also claims membership in the subfamily Cetoniinae, also known as the flower chafers, a group of diurnal beetles that feed on nectar, pollen, sap, and some, like are guy here, on damaged fruit. On Guam, where it is widespread, it has been known to feed on the flowers of papaya, coconut, betel nut, mango and corn, and may damage the flowers of these trees, resulting in fewer fruit.
Proteatia orientalis has been known on Oahu since 2002, and has since been identified on Maui, and just recently on the Big Island. Eggs are laid in the soil, where the grub, or larvae hatch and then pupate; as with all beetles, metamorphosis is complete, whereas true bugs undergo incomplete metamorphosis. The oriental flower beetle can be confused with the coconut rhinoceros beetle, Oryctes rhinoceros, a major pest of coconut palms that was first seen in Honolulu in December of 2013.

Though both are scarab beetles, the Oriental Flower beetle pictured here is about an inch long and bronze, whereas the rhino beetle is about two inches long and black. Photo: Jeanne Lindgren

The Coconut Rhinoceros beetle is a new arrivial, and a major pest of coconut palms. The Dept. of Agriculture for the state of Hawaii asks the public to report any sightings of rhino beetles or rhino beetle damage to the State Pest Hotline, 643-PEST (643-7378). Photo: HAH [CC-BY-2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons