Mass trapping with multiple CO₂- and octenol-supplemented Mosquito Magnet® X traps (MM-X), operated 24 h/day, 7 days/wk, from March through November 2008, at St. Andrews State Park on northwest Florida's Gulf Coast, did not significantly reduce mosquito numbers compared to nontreated control sites. Anopheles crucians, Aedes taeniorhynchus, Culex salinarius, and Culex erraticus were the predominant species. Culex coronator was also collected for the first time in the park. Failure to reduce a late season outbreak of Ae. taeniorhynchus within the trapping area required adulticide application to achieve mosquito control.