The dramatic reduction in weed coverage was the result
of the increasing amount of a natural pathogen already
present in the reservoir (Cercospora piaropi), and the
introduction, at the same time of another highly virulent
pathogen A. zonatum These effects worked together with the feed scars from the
insects in the leaves and the provoked damage on stems by
larvae. By this way, the insects increase the disease
incidence causing injuries in leaf tissue or through the
pathogen direct transmission