Seasonal abundance of Anopheles farauti (Diptera : Culicidae) sibling species in far North Queensland, Australia

In the Cairns area of far north Queensland, Australia, the seasonal abundan ce of Anopheles farauti Laveran sibling species was studied at 6 locations, representing 3 habitat types, between August 1995 and September 1997. A to tal of 45,401 An. farauti s.l. was collected using CO2 + octenol baited CDC light traps, and consisted of 29,565 An. farauti No. 2, 14,214 An. farauti No. 3, and 1,622 An. farauti s.s. The relative abundance of all 3 species differed significantly by season and location. An. farauti No.2 was the dom inant species except in Cairns, where An. farauti s.s. was most abundant, a nd at Ninds Creek, where An. farauti No. 3 predominated. The dominant speci es at each location was present year round, although peaks in seasonal abun dance were observed. An. farauti s.s. populations were highest during the w et season (January-April). In lowland freshwater swamp habitats and 1 brack ish location, An. farauti No. 2 was more abundant during the wet season. Ho wever, at the highland freshwater swamp habitat, populations of An. farauti No. 2 were highest during the late dry season and early wet season (Octobe r-December). There was a significant positive correlation of both temperatu re and. rainfall with An. farauti s.s. and An. farauti No. 2 trap collectio ns. There was a negative correlation between An. farauti No. 3 and temperat ure, indicating that this species may be more abundant during cool weather. Although there were significant relationships among weather variables and An. farauti s.l, collections, correlation values were generally low, indica ting that other factors may contribute to variability among An. farauti sib ling species tray, collections.