plant bug
/ˈplɑːnt bʌɡ/ /ˈplant bʌɡ/noun
Any hemipteran insect that infests and feeds on plants; especially (a) a mirid; (b) an aphid.
Origin
Mid 18th century; earliest use found in Richard Brookes (fl. 1721–1763), physician and author. From plant + bug.