Host Specificity of Anthonomus Tenebrosus (Coleoptera: Curculionidae), A Potential Biological Control Agent of Tropical Soda Apple (Solanaceae) in Florida (Report‪)‬

Tropical soda apple (TSA), Solanum viarum Dunal (Solanaceae), is an invasive weed native to southeastern Brazil, northeastern Argentina, Paraguay, and Uruguay that has invaded Florida grasslands and natural ecosystems. In 1988, TSA was first reported in the USA in Glades County, Florida (Coile 1993; Mullahey & Colvin 1993); the introduction pathway is unknown. In 1993, a survey of beef cattle operations in south Florida estimated 157,145 ha of infested pasture land, twice the infestation present in 1992 (Mullahey et al. 1994). The infested area increased to more than 303,000 ha in 1995-96 (Mullahey et al. 1998). Currently, more than 404,000 ha are believed to be infested in Florida (Medal et al. 2010b). Due, at least in part, to favorable environmental conditions, the lack of natural enemies (herbivores and pathogens), and seed dispersal by wildlife and cattle feeding on the fruits. TSA has been spreading rapidly and has been observed in the majority of the counties in Florida and also in Alabama, Georgia, Louisiana, Mississippi, North Carolina, Pennsylvania, South Carolina, Tennessee, Texas, and Puerto Rico (Bryson & Byrd Jr. 1996; Dowler 1996; Mullahey et al. 1993, 1998; Medal et al. 2003, 2010a). Although TSA has been reported in Pennsylvania and Tennessee, it is highly probable that does not overwinter in these states. Patterson (1996) studied the effects of temperatures and photoperiods on TSA in controlled environmental chambers and speculated that the range of TSA could expand northward into the midwestern US. S. viarum was placed on the Florida and Federal Noxious Weed Lists in 1995. TSA typically invades improved pastures, where it reduces livestock carrying capacity. Foliage and stems are unpalatable to cattle; dense stands of the prickly shrub prevent access of cattle to shaded areas, which results in summer heat stress (Mullahey et al. 1998). TSA control costs for Florida ranchers were estimated at $6.5 to 16 million annually (Thomas 2007), and economic losses from cattle heat stress alone were estimated at $2 million (Mullahey et al. 1998). TSA is a reservoir for at least 6 crop viruses (potato leaf-roll virus, potato virus Y, tomato mosaic virus, tomato mottle virus, tobacco etch virus, and cucumber mosaic virus) and the early blight of potato and tomato fungus, Alternaria solani Sorauer (McGovern et al. 1994a, 1994b; McGovern et al. 1996). In addition, major insect pests utilize TSA as an alternate host; including Colorado potato beetle, Leptinotarsa decemlineata (Say); tomato hornworm Manduca quinquemaculata (Haworth); tobacco hornworm, M. sexta (L.); tobacco budworm, Helicoverpa virescens (Fabricius); tomato pinworm, Keiferia lycopersicella (Walsingham); green peach aphid, Myzuz persicae (Sulzer); silverleaf whitefly biotype B of Bemisia tabaci (Gennadius); soybean looper, Pseudoplusia includens (Walker); and the southern green stink bug, Nezara viridula (L.) (Habeck et al. 1996; Medal et al. 1999; Sudbrink et al. 2000). TSA also reduces biodiversity in natural areas, ditch banks, and roadsides by displacing native vegetation (Langeland & Burks 1998). TSA interferes with restoration efforts in Florida by invading areas that are reclaimed following phosphate mining operations (Albin 1994).