Wigglesworthia glossinidia is a species of gram-negative bacteria that is a bacterial endosymbiont of the tsetse fly.

[2] Together with Buchnera aphidicola, Wigglesworthia has been the subject of genetic research into the minimal genome necessary for any living organism.

[3] Phylogenetic studies suggest that the symbiotic relationship between W. glossinidia began 59-80 million years ago.

[2] Without the vitamins Wigglesworthia produces, the tsetse fly has greatly reduced growth and reproduction.

[5] Since the tsetse fly is the primary vector of Trypanosoma brucei, the pathogen that causes African trypanosomiasis, it has been suggested that W. glossinidia may one day be used to help control the spread of this disease.