Hydrellia fly parasitic wasp Trichopria columbiana Ashmead (Insecta: Hymenoptera: Diapriidae)

Figure 3. Second or third instar larva of Trichopria columbiana (Ashmead).  Credit: Byron Coon, Argosy UniversityTrichopria columbiana is a parasitoid of Hydrellia fly species. Depending on the ecological role of the host species, it can have a positive or negative effect on biological control. Some Hydrellia species feed on the invasive aquatic weed hydrilla. After its introduction into the U.S. by the aquarium industry in the 1950s (Langeland 1996), various control methods, including biological control, were developed and used to manage infestations. Classical biological control studies were initiated in the 1970s, which led to the release of four insects in the U.S., two of which were the leaf-mining ephydrid flies, Hydrellia pakistanae and Hydrellia balciunasi. Despite successful establishment and range expansion of the Asian hydrilla leaf mining fly, Hydrellia pakistanae, population levels of the insect and associated plant damage have remained low. One of the potentially limiting biotic factors is parasitism by the native endoparasitic wasp Trichopria columbiana. This 6-page fact sheet was written by Byron R. Coon, Nathan E. Harms, Michael J. Grodowitz, Emma N.I. Weeks, and James P. Cuda, and published by the UF Department of Entomology and Nematology, June 2014.

Hydrilla Stem Weevil Bagous Hydrillae O’Brien

Figure 1. Adult of the hydrilla stem weevil, Bagous hydrillae. Credit: Gary Buckingham, USDA-ARSBagous hydrillae O’Brien is a semi-aquatic weevil that feeds on the aquatic invasive weed Hydrilla verticillata (L.f.) Royle. Larvae of the weevil mine hydrilla stems and the adults feed on the stems and submerged leaves. This weevil was discovered during overseas surveys for biological control agents for hydrilla during the 1980s and was first introduced to the U.S. in Florida in 1991 after extensive host-specificity testing. This 5-page fact sheet was written by Emma Weeks, Jim Cuda, and Michael J. Grodowitz, and published by the UF Department of Entomology and Nematology, June 2014.

Hydrilla leaf mining flies (unofficial common name) Hydrellia spp. (Insecta: Diptera: Ephydridae)

http://edis.ifas.ufl.edu/in1034Figure 1. Adults of hydrilla leaf mining fly, Hydrellia spp.Several native and introduced species of flies in the genus Hydrellia are important because they feed on hydrilla (Hydrilla verticillata L.f. Royle), an invasive aquatic plant that has been classified as a Federal Noxious Weed. Hydrilla has invaded aquatic ecosystems in Florida and across the U.S. Larvae of Hydrellia spp. mine the leaves of hydrilla. In Florida, there are four species that have been associated with the invasive aquatic weed hydrilla: two native species and two species that were introduced for biological control of hydrilla. The native species are Hydrellia bilobifera Cresson and Hydrellia discursa Deonier. The introduced species are Hydrellia pakistanae Deonier and Hydrellia balciunasi Bock. This 6-page fact sheet was written by Emma Weeks and James Cuda, and published by the UF Department of Entomology and Nematology, April 2014.

Classical Biological Control of Tropical Soda Apple with Gratiana boliviana (ENY865/IN971)

Figure 4. South Florida Water Management District staff member, Terri Torrens, releasing Gratiana boliviana adults on a tropical soda apple plant.Tropical soda apple is a prickly shrub native to South America. First reported in Glades Co., Florida in 1988, it later spread to Georgia, Alabama, Louisiana, Texas, Mississippi, Tennessee, North Carolina, and South Carolina. It is a major problem in pastures and conservation areas. Negative impacts of tropical soda apple include reduction of cattle stocking rates, competition with native plants, and the costs associated with its control. Dense thickets of the weed also can disrupt the movement of wildlife. This 4-page fact sheet provides a summary of the major steps of the successful biological control program against tropical soda apple in Florida. The article covers the importance of the weed, identification and biology of the biological control agent, rearing and release efforts, establishment and impact, and efforts to communicate the outcomes of the program to stakeholders. Written by R. Diaz, J. Medal, K. Hibbard, A. Roda, A. Fox, S. Hight, P. Stansly, B. Sellers, J. Cuda and W. A. Overholt, and published by the UF Department of Entomology and Nematology, November 2012.

Alligatorweed flea beetle Agasicles hygrophila Selman and Vogt (Coleoptera: Chrysomelidae: Halticinae) (EENY462/IN831)

Figure 2. Adult alligatorweed flea beetle, Agasicles hygrophila Selman and Vogt, on a damaged leaf. Note characteristic feeding scars.Alligatorweed is an aquatic weed native to South America that began threatening Florida’s waterways in the early 1900s. Alligatorweed flea beetles kill the plant by destroying its stored food and interfering with photosynthesis by removing leaf tissue. This insect has been an extremely effective biological control agent in coastal regions of the southeastern United States. This 3-page fact sheet was written by Ted D. Center, James P. Cuda, Michael J. Grodowitz, and published by the UF Department of Entomology and Nematology, October 2012.

EENY476/IN859 Alligatorweed thrips (suggested) Amynothrips andersoni ONeill (Insecta:Thysanoptera:Phlaeothripidae)

EENY476, a 3-page illustrated fact sheet by Ted D. Center, James P. Cuda, and Michael J. Grodowitz, is part of the Featured Creatures collection. It describes this natural enemy of alligatorweed — distribution, description, hosts, life cycle, and economic importance. Includes references. Published by the UF Department of Entomology and Nematology, June 2010.