Project Number: 6036-32000-051-014-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Jan 15, 2020
End Date: Mar 31, 2022
To improve the integrated pest management (IPM) of fire ants in the Coachella Valley, California, by: 1) Evaluating the effect of irrigation on fire ant bait efficacy to determine the need to withhold irrigation after bait application; 2) Identifying periods of peak mating flight activity to improve timing of bait applications; and 3) Determining the spread of fire ant biocontrol agents released in the Coachella Valley to assess their further utilization for fire ant IPM. The Coachella Valley encompasses heavily irrigated, urban landscapes, and seasonal rains within a desert climate. The surrounding desert limits the natural influx of fire ants which may facilitate successful IPM of this invasive ant once control strategies accommodate this unique habitat.
1) Compare the efficacy of standard fire ant bait on fire ants in field sites where irrigation is withheld after baiting and in sites that follow a normal, daily irrigation schedule. Based on our laboratory and field studies with standard and water-resistant baits, we hypothesize that fire ant bait efficacy will be similar at the irrigated and non-irrigated sites. If true, the logistical costs to withhold irrigation after bait applications can be saved. 2) Fire ant alate (winged reproductive males and females) traps will be used to monitor the occurrence of mating flights at 2-week intervals with the assistance of the Coachella Valley Mosquito & Vector Control District (CVMVCD) staff. Monitored sites will be irrigated, and temperature and precipitation data will be collected to correlate flights with weather events. Current alate trap designs will be improved (e.g. portability) to facilitate sampling. 3) The geographic spread of the fire ant biocontrol agents, fire ant decapitating phorid flies and Solenopsis invicta virus 3, we previously established in 2014-15, will be determined with sticky tri-stand traps, and PCR, respectively. Sampling locations for the biocontrol agents will start within 50 m of the vicinity of the release sites then extend radially for intervals of 1–10 km for at least 2 intervals beyond immediate vicinity of the release sites. Sites will be on road right-of-ways with good fire ant habitat. Sampling will occur in the Spring of 2021. Collected data will help guide the next steps in utilizing biocontrol agents in the Coachella Valley.