Various attempts have been made to control weeds by introducing insects to attack them. The most notable attempts at control have concerned the following:

Gorse by a seed weevil (Apion ulex); ragwort by the seed fly (Hylemyia seneciella), the leaf miner (Phytomyza atricornis), and the cinnabar moth (Tyria jacobaeae); St. John's wort by the beetle (Chrysolina hyperici); Mexican devil weed by the gall fly (Procecidochares utilis); manuka by blight caused by the coccid, Eriococcus orariensis.