Location: Insect Behavior and Biocontrol Research2013 Annual Report
1a. Objectives (from AD-416):
To characterize crop and weed hosts, and insect vectors of Groundnut ringspot virus to facilitate development of better management options for this newly emerging virus infecting Florida fresh-market vegetables including tomato and pepper.
1b. Approach (from AD-416):
Florida is home to a number of invasive and native thrips species (at least eight) that have been implicated in the transmission of other viruses related to Groundnut Ringspot Virus (GRSV). It is unknown which other thrips species are capable of transmitting GRSV. Therefore, locally important thrips species will be analyzed and compared for their ability to transmit the GRSV. The nucleic acid-based diagnostic test for Groundnut ringspot virus previously developed by ARS Scientists will be used to analyze natural and/or experimental plant hosts (crops and weeds) for this virus to develop a host range for the virus. The information generated from this research will be useful to fresh-market vegetable growers, the specialty crop industry, Florida Cooperative Extension Service, private crop consultants and Florida Department of Agriculture and Consumer Services (FDACS) to guide development of management strategies for this newly emerging virus.
3. Progress Report:
This research relates directly to Objective 1. Develop habitat manipulation strategies as components of IPM programs for polyphagous pests through behavioral and ecological studies of their interactions with host plants and natural enemies. During the period covered by this report, project personnel completed additional caged vector experiments using western flower thrips, including transmission tests with Tomato chlorotic spot virus (TCSV), which is closely related to GRSV. Additional experiments are underway to determine which host plants are most important for thrips acquisition (and subsequent transmission) of GRSV and TCSV. Results of parallel thrips transmission experiments with GRSV and TCSV have extended previous project work and continue to represent substantial progress in project efforts to determine which local thrips species are important for GRSV and TCSV transmission in Florida. Field and transplant house sampling of tomato, and also pepper, eggplant, potato and solanaceous weeds has continued with over 164 samples collected and tested during this reporting period. GRSV, TCSV and TSWV have all been detected in many locations in south Florida. Collectively, these results suggest that like GRSV, TCSV has become established in south Florida and make it important to continue to monitor tomato production for this newly detected relative of GRSV. An experimental host range determination for TCSV has continued in parallel to project work on GRSV. Collectively these results represent substantial progress in project efforts since TCSV is one of the parents of the Florida GRSV isolate. Weekly thrips counts and GRSV/TCSV incidence data from disease hotspots have been collected. These data will be used by other project personnel to prepare distribution maps of thrips and GRSV/TCSV for subsequent analysis. This activity will continue each season through the conclusion of the project. Field transect studies have continued in GRSV/TCSV hotspots. Resistant and susceptible tomato cultivars for field tests have been identified from greenhouse host range testing for use in field trials in the fall growing season.