In sections 18.041 to 18.161, unless the context otherwise indicates: (a) "governmental unit" means any city, county, or town; (b) "governing body" means a council, board, body or persons in which the powers of the governmental unit are vested; and (c) "mosquito abatement" means the control, abatement, or prevention of breeding of mosquitoes or such other insects or arachnids (ticks, mites, spiders) as provided in section 18.091.