adulticide
/ˌædəltɪˈsīd, -ˈsaɪd/Definitions
1. noun
The act of killing or destroying adult insects, especially as a form of pest control.
“The farmer used adulticide to control the mosquito population in the field.”
2. noun
A substance or agent used to kill adult insects.
“The researcher studied the effects of the adulticide on the local ecosystem.”