Green treefrogs (Hyla cinerea) and grasshoppers (Melanoplus differentialis and Conocephalus fasciatus) commonly observed in Arkansas rice fields, are dispersal vectors for Colletotrichum gloeosporioides f. sp. aeschynomens, a causal agent of anthracnose of northern jointvetch. Treefrogs and grasshoppers captured from rice or soybean fields with diseased northern jointvetch were placed in containers in contact with healthy northern jointvetch plants. An average of 90% of northern jointvetch plants was infected by the pathogen with up to 10 lesions per plant using treefrog vectors. Experiments were done in the greenhouse on frog dispersal by monitoring disease development from a point source in closed rice-weed patches. Treefrogs dispersed the pathogen from the source plant to healthy plants resulting in 95% infection. In the field, grasshoppers were frequently observed feeding on anthracnose lesions. In six separate experiments, approximately 20% of grasshoppers collected from fields with diseased northern jointvetch transferred the disease after feeding or contacting healthy plants. By feeding pathogen-free grasshoppers on anthracnose lesions, we found that 66% of these grasshoppers transferred the disease to healthy plants. The grasshopper may be important in spreading the inoculum among weed patches. Green treefrogs appear to be efficient vectors of the disease because they preferred northern jointvetch plants as shelters
Yang, X. B.; Tebeest, D. O.; and Moore, E. L.
"Biological Vectors for the Dispersal of Colletotrichum Gloeosporioides,"
Journal of the Arkansas Academy of Science: Vol. 46
, Article 18.
Available at: http://scholarworks.uark.edu/jaas/vol46/iss1/18