Survey of aquatic mite parasitism of mosquitoes in Maine

Parasitism in mosquitoes by aquatic mites (Acari: Parasitengona: Hydrachnid) has been documented around the globe. However, relatively few studies have examined the degree of parasitism in mosquito populations along large ecological gradients. The state of Maine presents a remarkably heterogeneous patchwork of ecological systems and is home to more than 42 species of mosquito. In this presentation we summarize results from two mosquito surveys, conducted in late June through early October in 2013 and 2014, examining the occurrence and degree of parasitism in adult female mosquitoes by aquatic mites in Maine. Samples were collected from southern, central, western, and northern sites. In 2013, 7516 adult female mosquitoes were captured and identified; overall, 13% were parasitized by at least one larval aquatic mite. The species with the highest observed rate of parasitism was Coquillettidia perturbans (27%), followed by Aedes Japonicus (24%). In 2014, 9,524 female mosquitoes were captured and identified; overall, 6% of these mosquitoes were parasitized by at least one mite. The species with the highest observed rate of parasitism for the 2014 season was Culex territans (15%) followed by Coquillettidia perturbans (12%). Further research is needed to determine the reasons for the variation in overall parasitism rate and in the most parasitized species between 2013 and 2014 however, the overall parasitism rate for both years was higher than overall parasitism rates reported in literature by similar studies. This may indicate that aquatic mites are acting as a natural control for Maine’s most abundant mosquito species.