COMPARISONS OF RICE FIELD MOSQUITO (DIPTERA, CULICIDAE) ABUNDANCE AMONG AREAS WITH DIFFERENT AGRICULTURAL PRACTICES IN NORTHERN THAILAND

Adult mosquitoes were collected from 3 areas in northern Thailand with different availabilities of rice fields for larval habitats by using blacklight, truck, and pig-baited traps. Culex tritaeniorhynchus Giles and Culex gelidus Theobald were dominant in all samples. Significant study-area differences were found in light and truck trap collections for Cx. tritaeniorhynchus and Cx. gelidus, but not for Culex vishnui T heobald + Culex pseudovishnui Colless. In pig-baited sample area diffe rences were significant only for Cx. gelidus. Adults of Culex fuscocep hala Theobald were relatively rare, comprising only 0.6-7.9% of the to tal mosquitoes collected. When compared with the results from previous studies in the Chiangmai areal we conclude that Cx. fuscocephala has become a minor species and that changes in the mosquito fauna have occ urred in northern Thailand.