Abstract
The tetranychid Mononychellus progresivus is considered an economic pest of cassava in Venezuela during the dry season. Dead individuals observed in a cassava plot under investigation for plant resistance to this species were found to have been invaded by a fungus that appeared similar to Triplosporium floridanum infecting Eutetranychus banksi in Florida, to a species of the same genus infecting Tetranychus evansi in Brazil. The Venezuelan fungus is described, and measurements of its structures are compared in a table with those of the other 2 isolates.
