Hawaii is home to several stink bug species, including both an established agricultural pest and a native species found nowhere else on Earth. The most common and problematic is the southern green stink bug (Nezara viridula), which has been in the islands for decades and causes real damage to crops like macadamia nuts. Whether you’ve spotted one in your yard, on your lanai, or on a hiking trail, here’s what you need to know.
Stink Bug Species in Hawaii
The southern green stink bug is the dominant pest species in Hawaii. Originally from Ethiopia, it’s now established across tropical and subtropical regions worldwide, including both Hawaii and parts of the mainland U.S. like California. Adults are shield-shaped, bright green, and roughly half an inch long. They feed on a wide range of plants by piercing fruit, nuts, and seeds with their needle-like mouthparts and sucking out the contents.
Hawaii also has a native stink bug worth knowing about: the koa bug (Coleotichus blackburniae). It’s the largest native true bug in the islands and lives only on endemic koa and ʻaʻaliʻi trees. The koa bug is visually striking, with a broad, colorful body that sets it apart from the plain green agricultural pests. Unfortunately, its population is in decline, partly because a parasitic fly introduced to control pest stink bugs also attacks koa bugs. If you encounter one on a koa tree, it’s a native species and not a pest to worry about.
Damage to Hawaiian Agriculture
The southern green stink bug is a serious pest of macadamia nut orchards, one of Hawaii’s most valuable crops. USDA research conducted in Hawaiian orchards found that roughly 50% of observed nut damage at harvest actually happens while the nuts are still hanging in the tree canopy, not after they fall to the ground. This matters because it means damage is already done before growers can easily detect it during harvest collection.
Long-term data from Hawaiian macadamia orchards show distinct seasonal peaks in damage, with mean damage levels staying fairly low overall but punctuated by periodic spikes. The bugs pierce the developing nutshell and feed on the kernel inside, leaving behind discolored, shriveled, or unmarketable nuts. Beyond macadamia, southern green stink bugs also feed on tomatoes, beans, peppers, and other garden crops across the islands.
To help manage the problem, biological control agents have been introduced in Hawaii. Certain parasitic wasps that attack stink bug eggs were brought to the islands specifically to reduce southern green stink bug populations in agricultural settings.
Are They Dangerous to People or Pets?
Stink bugs don’t bite, don’t sting, and don’t transmit diseases. They pose no physical threat to you or your pets. Their only real defense mechanism is the foul-smelling liquid they release when disturbed or crushed, which is where the name comes from.
That said, a small number of people are allergic to the compounds in that defensive spray. If you’re one of them, handling or accidentally crushing a stink bug can trigger a runny nose or skin irritation similar to contact dermatitis. The reaction is mild for most people, but if you notice it happening, avoid handling them with bare hands.
Keeping Stink Bugs Out of Your Home
Stink bugs are attracted to light and drawn to fruit, so two simple changes help reduce encounters: keep outdoor lights off in the evening when possible, and pull window blinds down after dark. These steps alone cut down on how many bugs gather near your doors and windows.
The most effective long-term strategy is sealing entry points. Check for gaps around windows, doors, utility pipes, and vents. Repair torn screens and add weatherstripping where needed. In Hawaii’s mild climate, stink bugs don’t go through the same intense fall home-invasion behavior seen on the mainland with brown marmorated stink bugs, but they still wander indoors, especially when lights attract them at night.
Once stink bugs are inside, insecticides aren’t particularly effective and aren’t worth the hassle. A vacuum cleaner is your best tool. Just empty the bag or canister promptly afterward, because the bugs will release their odor inside it. A broom and dustpan work fine too. The key is not to crush them against walls or fabric, since the smell lingers and can stain light-colored surfaces.
Reporting Unusual Stink Bug Sightings
Hawaii takes invasive species seriously, and if you spot a stink bug that looks unfamiliar, particularly one that’s brown and mottled rather than solid green, it’s worth reporting. The brown marmorated stink bug, a devastating agricultural pest on the mainland, is not established in Hawaii, and keeping it out is a priority.
The Hawaii Invasive Species Council runs a statewide pest hotline at 808-643-7378 (643-PEST). You can also report sightings online at 643pest.org, where you can pinpoint your location on a map and upload photos. The site even has a data dashboard showing what other people across the state have been reporting, which can help you identify whether what you’re seeing is already known in your area.