Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2010
Publication Date: 3/31/2010
Citation: Medal, J., Bustamente, N., Overholt, W.A., Diaz, R., Stansly, P., Roda, A., Amalin, D., Hibbard, K., Gaskalla, R., Sellers, B., Hight, S.D., Cuda, J. 2010. Biological control of tropical soda apple (Solanaceae) in Florida: Post-release evaluation. Florida Entomologist. 93(1):130-132. Interpretive Summary: Tropical soda apple (TSA) is native to South America and was first found in Florida in 1988. The plant spread and has become a problem in pastures throughout the southeastern U.S. from Texas to the Carolinas. Cattle avoid the spiny leaves and stems of TSA and the weed can take over a pasture. Scientists with USDA-ARS Center for Medical, Agricultural and Veterinary Entomology in Tallahassee, FL, along with University of Florida, APHIS, and Florida Division of Plant Industry researchers, are studying a leaf-feeding beetle from Argentina that eats nothing but TSA. A field release of the beetles was made in a Sumter Co., FL infested pasture to evaluate the impact of the beetles on TSA plants. Beetle feeding caused substantial defoliation to TSA plants and resulted in fewer fruits being produced by the plants. Number of beetles increased at the site and they dispersed on their own onto other TSA plants at about 1.5 miles per year. Field releases of the beetles and evaluations of their damage to TSA plants is continuing across Florida.
Technical Abstract: The leaf feeding beetle Gratiana boliviana Spaeth (Coleoptera: Chrysomelidae) was released as a biological control agent against tropical soda apple (TSA) (Solanum viarum Dunal (Solanaceae)) in Sumter County, FL in 2006. Evaluation of beetle feeding damage to TSA plants and changes in the beetle population were conducted over the following two years. The beetles significantly defoliated the plants over the summers of both years and reduced the number of fruits produced by TSA plants attacked by the beetles from 35 fruits/plant to less than 5 fruits/plant. The beetles became well established in the area and dispersed 1.6 to 3.2 km/year.