Coffee rust is caused by the fungus Hemileia vastatrix, an
obligate parasite that affects the living leaves of the genus
Coffea. Among the cultivated species, C. arabica is the most
severely attacked. The disease causes defoliation that, when
acute, can lead to the death of branches and heavy crop losses
(Fig. 1). The infectious form of H. vastatrix is the uredospore
(Fig. 2). The first symptoms are small yellowish lesions that
appear on the underside of leaves (Fig. 2b), where the fungus