Sweet Potato Bug "Hungry Sumo Bugs"

The Sweet Potato Bug (Physomerus grossipes) is a fruit-devastator and is known as a Sumo Bug with its extra thick daikon radish shaped thighs (femora). It looks as if it is a heavy-lifting, thigh-flexing rustic-grey wrestler of the garden, while its appetite for garden plants knows no end — it is also sometimes called the "Large Spine-Footed Bug" by bug aficionados. When people start gardens this is one of the first visitors they find on their plants. They will move in and start pillaging, they are big, they’re loud when they move, and will be quick to ruin a persons choice harvest. Seeing a massive huddle of these prehistoric-looking beasts on your vines is enough to trigger an immediate, visceral reaction as one person said: "There is absolutely nothing "Aloha" about them."

Lately, there have been heaps of reports of these bugs across the islands, from the humid backyards of Puna to the sunny slopes of Kona. People always ask, "Friend or foe? Native or non-native? and eat anything if its available as the garden is their buffet. They are 100% non-native, originally from Southeast Asia, and officially detected in the islands in August 1997 by (HDOA & DLNR). It was first reported by Leeward Community College, Oahu, Pearl City, where they were found hanging out on hibiscus plants, noni plants, and all sorts of native plants. By the early 2000s they got to the Big Island where they had the most of any island in Hawaii. They got here by hitching a ride on imports from the shipyard. Historically South East Asia holds around 11% market share for agricultural products and come from: Indonesia, Malaysia, Vietnam, and more.

As they grow, you’ll see the nymphs (instars)—the teenagers of the bug world. These guys have "nasty pokies" on their backs and are often more destructive than the adults. They grow in batches of 50 miniature potato bugs from a single female, which can produce every two weeks, and reach adulthood in two months. They produce fast, to say the least. When a fresh batch of newborns emerge, they are very orange, reddish, and cluster-hudde on stems and under leaves as night shift workers where its most comfy for them to hide from 9 PM to 3 AM. This bundle will consume all the liquids inside the plant, leaving it withered, waterless, and dead.

Life Cycle of the Sumo Wrestler
Clusters of eggs appear bronze, bean-shaped egg cases, almost like caviar. You’ll find these "bronze eggs" underneath any sort of tree leaves, on the undersides of your vines, or even on your garden fence posts. As one gardener noted, "They have been laying those bronze eggs underneath my calamansi leaves!". When they hatch the Nymphs immediately start "tunneling and pooping their way" through every plant, since they don't have wings yet, so they concentrate on destroying an entire plant one at a time. "I find nymphs and instars with nasty pokies on their backs killing my tomato plants when I don't put a great deal of time into killing the adults."

Once they acquire wings and those massive thighs, they are ready to reproduce. A single female can produce an army of them in a massive amount of offspring, increasing the problem really quick. When checking one Oahu garden there were 20 adults in the colony throughout one house, about 5 mating pairs, and over 200 nymphs. This means that there could be well over 1000 bugs across all stages in one yard. Despite their name, these bugs aren't picky eaters. While they love the morning glory family (‘uala) and beans (Leguminosae), they are spreading to other edibles and "ravaging" everything in sight. "They are spreading to other edibles now!".

Sweet Potato Bugs use their piercing-sucking mouthparts—essentially "dirty needles"—to suck the nutrients and juices out of your plants as giant mosquitos that love plant juice, so the juicier the plant, the more delicious it looks to them. In tomatoes, this is devastating, since they leave sunken, dark spots on the fruit that eventually rot. They’ve even been spotted on Noni, Lime trees, and Pomegranates.

These buggahs have become overtime pesticide resistant, so there are not many ways to get rid of them, except the old fashion way of smashing them physically. Some of the older folks have several suggestions like: (1.) Getting a container and drop the adults in it by using Tweezers, but make sure to put either rubbing alcohol or strong dishwashing soap. (2.) Ziplock Bag (The Hilo Method) "I actually put them in a ziplock bag and took a photo to send to Hilo Agg. Department." They get back to you quickly and will confirm that these are devastating to growers and tell you additional information about them. (3.) Sprinkle Diotamacious (sp) all around and it tears at their undersides. Vinegar the Weeds, use white vinegar on a foam brush to kill weeds nearby. These sumos hide in the weeds during the day, so taking away their hiding spot helps.