Flooding water mosquitoes mainly caused nuisance problems and outbreak of West Nile and Eastern Enquire Encephalitis at sometimes. The populations of flooding water mosquitoes usually outbreak after 4-5 inches of rain fall in St. Johns County, northeastern Florida. During the development of residential communities /subdivisions, the trees and vegetation have been cut/removed and the lots have been filled and brought up. The retention ponds and ditches have been digging between the subdivisions and woody area. Most of the woody area become wetland or the area where is suitable for mosquito larval breeding and adult activity, such as sugar/plant feeding, water drinking, and hiding. Control of the mosquitoes around these areas become a challenge by ground application due to inaccessible problem. In the past few years, Anastasia Mosquito Control District, St. Augustine, Florida has adopted a new strategy to conduct barrier treatment of specific zone/edge between the residential subdivision and the woody area by aerial application. Based on positive larval survey and increased number of adult mosquitoes detected by human landing rate counts (LRC) and CDC light trap collection, an aerial larviciding mission with granule methoprene at 10 pounds/acre or an aerial adultciding mission with naled product at 0.6 O.Z. per acre were planned and conducted. For the larval control mission by aerial application, the helicopter flew one pass spraying on the edge between the woody area and subdivision. The spraying swap is/covers 300-400 ft. For aerial adulticiding, the helicopter flew one pass spraying. The swap is and covers 1,500-3,000 ft based on the variation of wind speed. Based on the comparison of data (number of resident complaints or service requests, LRC, number of positive larvae survey and number of trap collection) pre-treatment and post-treatment, the barrier treatment at the edges between residential subdivision and woody area by aerial larviciding provided 80%-100% control of flooding water mosquitoes. The barrier treatment for the edges between residential subdivision and woody area by aerial adulticiding provided 90%-100% of control of adult mosquitoes. The aerial barrier treatments are not only providing effective control of larval and adult mosquitoes, but also reduce the amount of pesticide applications and hours used for a whole area spraying. In addition, this strategy and method benefit to environments and have received more positive responses from the residents.
