YELLOWFEVER MOSQUITO (DIPTERA, CULICIDAE) INTRODUCED INTO LANDI-KOTAL, PAKISTAN, BY TIRE IMPORTATION

Although the recent distribution of yellowfever mosquito, Aedes aegypt i (L.), in Pakistan has been restricted to the port city of Karachi, a dult and immature mosquitoes breeding in imported tires in warehouses at Land Kotal (North-West Frontier Province) were identified as Ae. ae gypti. The patterns of tire trade and the current disjunct distributio n of Ae. aegypti indicated that the introduction into Landi Kotal may have been either from Karachi or India. Thermal fog application of pir imiphos-methyl and residual spray of malathion during 1993 reduced abu ndance in October-November. Living larvae or adults were not found dur ing January 1994, apparently because of cold weather. However, Ae. aeg ypti reappeared during May-June 1994, most probably from eggs that ove rwintered. Population increased during late August when another round of spray using the same insecticides and fenthion as an additional lar vicide again reduced abundance. Although this mosquito apparently has not spread into neighboring areas, its survival at Landi Kotal through all seasons despite control measures indicates its potential of becom ing established in other areas of Pakistan.