Wikipedia

Wolbachia is a genus of gram-negative bacteria infecting many species of arthropods and filarial nematodes. The relationship between Wolbachia and its hosts ranges from parasitism through benign symbiosis up to obligate mutualism. It is one of the most common parasitic microbes of arthropods, and is possibly the most widespread reproductive parasite bacterium in the biosphere. Its interactions with hosts are complex and highly diverse across the various species in which it is found. Some host species cannot reproduce, or even survive, absent internal Wolbachia colonies. One study concluded that more than 16% of neotropical insect species carry bacteria of this genus, and as many as 25 to 70% of all insect species are estimated to be potential hosts.