Platyphora (about 450 species) have been recorded primarily on plants in the Common Milkweed group. A similar genus, Doryphora (10 species) has been collected mostly on members of the Dogbane family. In both genera, males and females have an unusual horn arising from the ventral surface of the mesothorax; typically this horn points forward and down.
Photo location: Santo Domingo de los Colorados, Ecuador.
Determined by Dr. Donald Windsor, Smithsonian Tropical Research Institute.
American Insects site