Moniliophthora perniciosa

Moniliophthora perniciosa is a basidiomycete fungus in the family Marasmiaceae with a hemibiotrophic life cycle, meaning it first grows within living host tissue before switching to feeding on dead tissue. It causes witches' broom disease of cacao, named for the broom-like malformed shoots that result from abnormal tissue growth, and it can also cause cacao pods to develop without seeds. The fungus is thought to have co-evolved with cacao in the Amazon basin and today its four biotypes are found across South America, Panama and the Caribbean, also affecting some other plants in the mallow and nightshade families. Its economic impact has been severe: after the disease reached Bahia state in Brazil in 1989, the state's cacao output collapsed from about 380,000 to 90,000 metric tons a year, turning Brazil from the world's third largest cacao exporter into a net importer, with ripple effects on global cocoa supply and on land use as affected growers converted forest to other production. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/