Characterization of life-shortening Wolbachia infection in Aedes albopictus (Asian tiger mosquito)

Female mosquitoes that acquire a pathogen must survive the extrinsic incubation period to transmit disease. Therefore, reducing the average life-span of female mosquitoes is expected to reduce disease transmission. The popcorn (wMelPop) strain of the endosymbyotic Wolbachia bacteria induces life-shortening in its host, Drosophila melanogaster. Popcorn infections also induce cytoplasmic incompatibility (CI) in D. melanogaster, resulting in reduced egg hatch rates in females mated by incompatible males. Introduction of wMelPop into Aedes albopictus embryos provides an extreme example of Wolbachia as a pathogen. In addition to reduced longevity and fecundity, abnormally high popcorn density is associated with embryonic mortality, masking the typical pattern of CI. The results are consistent with earlier reports that show unpredictable shifts in the Wolbachia phenotype following interspecific transfer. Such shifts can complicate proposed strategies to modify the age structure of medically important vector populations.