December 31, 2010
December 31 - Guignardia bidwellii
As you raise your glass of champagne tonight and toast this wonderful year of biodiversity, don't forget the parasites. And, to help you remember, today's parasite is after the grapes cultivated for wine. Guignardia bidwellii is a species of ascomycetous fungus that causes a disease called "Black rot" in many varieties of grapes in North America and now Europe, South America, and Asia as well. The vectors of this disease are not mosquitoes nor plant bugs, but rather raindrops, which splash the infective spores onto uninfected plants. Infection of the fruits will cause the grapes to shrivel up into what are known in the industry as "mummies" and these can serve as a good place for the fungus to overwinter.