A sexually transmitted disease that is said to turn cicadas into ‘zombies’ and causes their private parts to fall off has been detected in southern parts of Illinois and is expected to reach the Chicago area within weeks.

The infection is a white fungus called Massospora cicadina that takes over the male and causes the gonads to be torn from the body. The chalky spores that are released are spread to other nearby cicadas.

The Massospora cicadina, which targets only the 13- and 17-year periodical cicadas, has already infected cicadas in Champaign and is expected to migrate north to the Chicago area, according to Jim Louderman, a collection’s assistant at Chicago’s Field Museum of Natural History.

The fungus is also the type that has hallucinatory effects on birds that would eat infected cicadas.

The emergence of billions of buzzing, clicking cicadas is underway. In northern Illinois, we’re seeing the Brood XIII of periodical cicadas that were born in 2007. Another variety, Brood XIX, is emerging in central and southern parts of the state. Thomas Jefferson was president when the two broods last emerged together in 1803.