Revisited ITS2 phylogeny of Anopheles (Anopheles) Hyrcanus group mosquitoes: reexamination of unidentified and misidentified ITS2 sequences.

The Anopheles (Anopheles) Hyrcanus group of mosquitoes is very important for human health because some are malarial vector mosquitoes. Despite their pathological importance, some unidentified internal transcribed spacer 2 (ITS2) sequences have been reported from members of this group, and their phylogenetic relationships have been rarely understood. In the present study, 84 ITS2 sequences for the Hyrcanus group members were retrieved from GenBank. The detailed sequence comparison unambiguously revealed that the unknown1 sequences of Li et al. (Zootaxa 939:1-8, 2005), YM-2004 (or sp.2) of Ma and Xu [J Med Entomol 42(4):610-619, 2005], Anopheles sp. of Ree et al. (2005), and Anopheles lesteri reported by Gao et al. [J Med Entomol 41(1):5-11, 2004] are identical to Anopheles belenrae [Rueda (Zootaxa 941:1-26, 2005)] and that YM-2003 (or sp.1) of Ma and Xu [J Med Entomol 42(4):610-619, 2005] is closely related to A. lesteri. In addition, some candidate species that may be synonymized are suggested in addition to the possibility that A. lesteri may be divided into at least three types: A, B, and C. The neighbor joining, maximum parsimony, and maximum likelihood trees show that the 23 examined Hyrcanus group members could be divided into four subgroups. The phylogenetic relationships among them are generally well resolved with high bootstrapping values (60-100%), and they are consistently supported by all three trees without any conflicts. These results may strongly suggest that the morphology-based groupings of the Hyrcanus group members should be seriously reconsidered. Further study must be conducted to address the following issues: the three or more multitypified A. lesteri; the unidentified YM-2003 closely related to A. lesteri; and the synonymies of Anopheles peditaeniatus/Anopheles nigerrimus, Anopheles kunmingensis/Anopheles liangshanensis, Anopheles pullus/Anopheles junlianensis, and Anopheles engarensis/Anopheles kleini.