Tarantism is a form of hysterical 'dancing' behaviour, popularly believed to result from the bite of the Wolf Spider and/or the Mediterranean Black Widow or Steppe Spider.

However, no link between such bites and the behaviour of tarantism has ever been demonstrated.

It probably has historical connections with the 'outbreaks' of Dancing Mania which happened in Europe between the 14th and 17th centuries. Now thought to be manifestations of mass psychogenic illness.

Although the popular belief persists that tarantism results from a spider bite, it remains scientifically unsubstantiated. Donaldson, Cavanagh, and Rankin (1997) conclude that the actual cause or causes of tarantism remain unknown.

Source : Wikipedia