Wolbachia is a
genus of
bacteria which infects
arthropod species, including a high proportion of
insects, as well as some
nematodes. It is one of the world's most common
parasitic microbes and is possibly the most common
reproductive parasite in the
biosphere. Its interactions with its hosts are often complex, and in some cases have evolved to be
mutualistic rather than
parasitic. Some host species cannot reproduce, or even survive, without
Wolbachia infection. One study concluded that more than 16% of
neotropical insect species carry bacteria of this genus, and as many as 25 to 70 percent of all insect species are estimated to be potential hosts.