Phylogenetic tree of Culex spp. based on COI gene sequence. (A) Summarized Bayesian phylogenetic tree with 182 total COI haplotypes. Culex sitiens were used as an outgroup. (B) Expanded subtree of 15 haplotypes from 28 Cx. sitiens. (C) Expanded subtree of 33 haplotypes from 37 Cx. palpalis individuals. (D, E) Expanded subtree of 134 haplotypes from 208 Cx. annulirostris individuals. Bayesian tree was reconstructed based on nucleotide sequence alignment of 538 aligned coding positions using MrBayes 3.1.2 with a mixed nucleotide model. Bayesian posterior probabilities/ML bootstrap support values calculated with PhyML 2.4.4 (500 replicates) are shown (>50/50%). For details about phylogenetic reconstruction see Materials and Methods.