Is it ensure, insure, or assure?
acaricide a·car·i·cide (ə-kār'ĭ-sīd')
Destructive to acarids. n.
An agent that destroys acarids.
any chemical substance used to control mites or ticks (especially species that damage ornamental or food plants), which are not susceptible to commonly used insecticides. Azobenzene, dicofol, ovex, and tetradifon are commonly used miticides. Many miticides kill eggs and larval stages as well as adult animals. Some are also toxic to honeybees and other beneficial insects.