Serinethinae is a subfamily of the hemipteran family Rhopalidae, sometimes known as soapberry bugs. They are brightly-colored seed eaters, comprising two or three genera and about seventy species. These bugs are specialists on soapberry plants (Sapindaceae); that is, they feed on the berries and reproduce on the stems and leaves of these plants. An example is J. haematoloma, a soapberry bug found in Florida and well-known for its rapid adaptive evolution following the introduction of a non-native soapberry plant to its native environ. The boxelder bug is a common example of a soapberry bug.