A new study of genetic samples from Aedes aegypti mosquitoes from around the world finds no evidence of naturally occurring infection with Wolbachia bacteria. When artificially introduced to mosquito populations, Wolbachia can be used for reducing mosquito numbers or interrupting their ability to transmit disease-causing pathogens. The lack of naturally occurring Wolbachia removes “additional variables … that would need to be taken into account” in such efforts, researchers say. (Photo credit: Tommaso G. Chiodo)