jointworm

noun

joint·​worm ˈjȯint-ˌwərm 

: the larva of any of several small chalcid wasps (genus Tetramesa synonym Harmolita) that attacks the stems of grain-producing plants (as wheat or barley) and causes swellings like galls at or just above the first joint

Word History

First Known Use

1851, in the meaning defined above