Oriental Flower Beetle "The Hibiscus Eater"

The Oriental Flower Beetle is often seen in Hawaiian gardens and is known as the Pretty Green Beetle or Protaetia fusca. It’s a bumbling, armor-plated samurai that sounds like a miniature helicopter with a loose screw. You’ll be sitting on your lanai, and hear a whirr-thump! this metallic tank misses its landing and crashed into your neck, and rolls down to your shoulder. It’s not graceful, it’s not quiet, and it is round. Its ornamental in most cases, so don't be so quick to reach for the slipper. In its appearance it has a iridescent sheen, deep chocolate and jewel-toned green. It is a "pretty" pest that somehow manages to be both a nuisance, an accidental pollinator, and a visitor in your hale.

The Oriental Flower Beetle didn't swim here, and it didn't come in a crate of fruit, but it came from the Military Aircraft at Hickam Air Force Base on Oahu from Japan According to the Hawaii Department of Agriculture (HDOA). It most likely was crawling into the wheel wells or cargo holds before takeoff. The species was first reported in Hawaii in 1952 (Hawaiian Entomological Society), then by the late 1970s and early 80s, they had jumped the channels to the other islands. Today, they are firmly established on Oahu, Maui, Kauai, Molokai, Lanai, and the Big Island. If there’s a garden in the state with a blooming mango or hibiscus, they’re likely there. By 2002, the HDOA officially declared them "fully established" across all the major islands.

Mulch has all sorts of grubs and if you find one that is of this bugs type it will crawl on their backs with its legs in the air. This is the primary field test used by HDOA inspectors to tell "good" bugs from the "dangerous" bugs Coconut Rhinoceros Beetle (CRB), which crawls on its side. These larva tend to be kept by bug lovers as pets. The Scientific records confirm the adult lifespan is roughly 6 to 7 months.  

Unlike the baddy bugs that wait for the lights to go out to meet up with their gangs, the Flower Beetle is a dedicated day-tripper. They follow the flowers; if you have a lot of fruit blossoms in bloom—like mango, Lilikoi, you’ll see a bunch of them show up to wreck them before the fruit can set in. The University of Hawaii College of Tropical Agriculture and Human Resources (CTAHR) explicitly notes their attraction to mango blossoms and their habit of feeding on overripe or bird-damaged fruit. While they are primarily pests, entomologists recognize them as "accidental pollinators" because they move from flower to flower covered in pollen, even if they're eating the petals as they go.

You might find one in your house occasionally, but don't panic—they aren't looking to infest your kitchen. They usually get inside by accident, either flying through an open door or hitching a ride on your shirt after a gardening session. Unlike other pests, they won't find much to eat inside, and they’ll likely just buzz loudly against your window until they run out of steam.

Believe it or not, these guys make decent, low-maintenance pets. I once kept one in a half-gallon plastic jar on my desk at work for a few months. It eats weed flowers, or bits of fruit a few times a week. While they aren't dangerous to humans, their rapid reproduction can overwhelm a backyard. If your fruit trees are being picked clean to the point of no harvest, it’s time for action, treat the soil to stop the grubs before they ever get the chance to grow their wings and start their clunky, beautiful, annoying flights through your life.