VALIDATION OF CO2 TRAP DATA IN THREE EUROPEAN REGIONS

Abstract:
CDC traps are employed as an efficient tool in monitoring mosquito population changes, evaluation of climatic and human made changes on species abundance and composition as well as for estimation of success of control programs. Despite the great advantage in labor saving and sampling the species which are slightly or not attracted to man, compared to classical human bite sampling, usage of traps is constrained to the districts which can provide technical support, gaseous CO2 or dry ice. The sampling efficacy and accuracy depend on many factors such as: the mosquito species, the weather conditions, the terrain features, the trap construction, the trap site selection, the height of trap position, the amount of CO2 release and the sucking power, although several other elements could play an important role as well. Several attempts have been made to produce results of trap catches less variable on the site, more uniform at different sites and more reliable in practical application. In Germany females of Ae. vexans dominated between at ground level whereas at the height of 10 m Cx. pipiens was by far the most abundant species. In urban conditions, Cx. pipiens fly up to the level of 45 m. Ae. vexans actively migrates 1-2 km per night while, snow-melt mosquitoes migrate less than 2 kilometers during adult life. In Italy the mosquito nuisance would be considered intolerable with over 30 females of Aedes/trap/night or 200 females of Culex/trap/night. Our investigation demonstrated that Ae. geniculatus, Ae. sticticus and An. plumbeus were attracted more by human bait than by carbon dioxide. There was no significant differences between both numbers and species of mosquitoes caught by CO2 + light and by CO2 alone.