Submitted to: Journal of Heredity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/24/1996
Publication Date: N/A
Interpretive Summary: Anopheles rangeli and Anopheles trinkae are mosquito species that have been shown to transmit malaria in South America. However, it is possible that these two species are actually species complexes. Morphologically similar species are common in insects, and most morphologically described species of Anopheles mosquitoes are complexes of species. Species complexes are of great practical importance for two reasons: 1) some species of the complex might not be pests and control efforts directed at the complex as a whole would therefore be partly wasted; and 2) control strategies directed against one species of the complex might not affect other species of the complex. By studying the population genetics of these species and other species of mosquitoes, we can determine how many species there are, which ones transmit malaria, and how they can be controlled.
Technical Abstract: We analyzed mitochondrial (mt) DNA variation in samples of two morphologically similar mosquitoes, Anopheles rangeli (n=182) and A. trinkae (n=45), with very different distribution patterns in Latin America, to assess species boundaries for these putative sister taxa and to examine population genetic structure. Phylogenetic analyses revealed (1) support for the monophyletic origin of each species; (2) diagnostic restriction site differences between both species; (3) geographic partitioning of haplotypes by country in A. rangeli from Bolivia, Ecuador and Venezuela compared with considerable overlap in haplotypes of A. trinkae from Bolivia and Ecuador; (4) a strong suggestion of population substructuring in A. rangeli; and (5) similar levels of mean haplotype and nucleotide diversity in both species but lower levels of mean nucleotide divergence in A. trinkae compared with A. rangeli. We hypothesize that higher maternal gene flow and lower divergence in A. trinkae are most likely due either to a distinctive matrilineal history or to a smaller effective population size, which may have been influenced by a smaller, essentially linear geographic range along the eastern flank of the Andes. In the cladistic analysis of A. rangeli, the Bolivian haplotypes appear to be more derived than those from Ecuador or Venezuela, yet there is no evidence to support the hypothesis of a recent range expansion from Ecuador to Bolivia.