JM Beuzelin1 and MT VanWeelden 2
1University of Florida Institute of Food and Agricultural Sciences, Everglades Research and Education Center, Belle Glade, Florida, USA; jbeuzelin@ufl.edu
2University of Florida Institute of Food and Agricultural Sciences, Palm Beach County Extension, Belle Glade, Florida, USA
At least 14 arthropod species have been listed as pests of sugarcane in Florida, which is produced in the southern region of the state on 160,000 ha. Among these pests, stemborers (Lepidoptera: Crambidae) and wireworms (Coleoptera: Elateridae) are major concerns. Populations of one stemborer, Diatraea saccharalis, were managed throughout the 1980s using insecticides applied when larval infestations exceeded a 2-3% threshold. However, areawide releases of Cotesia flavipes during the 1990s decreased the need for insecticides, which have not been used for the past 25 years. Recent on-farm surveys indicated that D. saccharalis populations occur below economic levels thanks to parasitism by C. flavipes and predation by ants including Solenopsis invicta. Another stemborer, Eoreuma loftini, was first observed in the central region of Florida in 2012. Pheromone trapping conducted since 2012 shows that populations of this invasive insect have expanded their geographical range southward at approximately 4 km/year. Additional trapping suggests that E. loftini has not become established in the sugarcane producing region of Florida. Thus, stemborers are not the focus of an active management strategy under current sugarcane production practices in Florida. Wireworms, however, are controlled either using a flooded fallow, or rotating with flooded rice, or most often using an insecticide at planting. Phorate, an organophosphate, is currently used for wireworm management, but less hazardous insecticides have been studied to provide reduced risk alternatives. Thiamethoxam and broflanilide protect young sugarcane plants from injury caused by Melanotus communis, the most prevalent wireworm species in Florida sugarcane. However, the regulatory process for the registration of thiamethoxam and broflanilide has stalled. Thus, a wireworm management strategy less reliant on insecticides should be developed.