Sweet Potato Bug
This pest is widespread
The sweet potato bug (Physomerus grossipes) is a common garden pest around late winter and early spring. This is a member of the leaf-footed bug family (Coreidae). It uses its piercing-sucking mouthpart to suck nutrients from plants. It normally feeds on members of the nightshade family (Solanaceae), like sweet potatoes and tomatoes, and the bean family (Fabaceae). While it can cause plants to wilt and become discolored it does not cause any plant death, so it is considered a minor pest.
These bugs tend to gather in swarms and sit on plants that they don’t necessarily feed on. They lay their eggs on flat surfaces, like the undersides of leaves, which are then guarded by the female.
Native to Southeast Asia. Most likely got to Hawaii by an accidental introduction by hiding in imported plants in the early 2000s. The sweet potato bug is widespread and can be found all over the Big Island. No reporting is necessary.
Sweet Potato Bug (Physomerus grossipes)
Photos L-R: Alistair Bairos, BIISC
- Sucks nutrients from plants causing wilting and discoloration
- Reduces fruit yield
- Adults are about 1 inch long
- Brown mottled color
- Enlarged tibia (thighs)
- Wings fold over each other at the end of the body making a dark-colored diamond
- Edges of the body are orange
How to control sweet potato bugs:
Sweet potato bugs are rather resilient to pesticides so the easiest way to get rid of them is by physical removal. Fill a bucket with soapy water and pluck the bugs off the plants and dump them into the bucket. Sweet potato bugs are rather docile and won’t scatter too much when disturbed.