Mosquito collections and surveys can be made by hand and traps. Identifying the collection will indicate the species present and their relative density. The species will give a fair indication of the breeding places. Location of breeding places should be found to determine control methods most suitable from a practical and economical standpoint. Mosquitoes can be examined for the presence or absence of encephalitis and other viruses at the Ohio Department of Health, Vector- borne Disease Unit, Columbus, Ohio 43229.