1a. Objectives (from AD-416):
To determine the feasibility of using a bait formulation to deliver double stranded RNA (dsRNA) complimentary to the yolk protein receptor (VgR) specific to fire ant queens to stop egg-laying.
1b. Approach (from AD-416):
1) Design dsRNA to VgR from the fire ant. 2) Synthesize a dsRNA VgR that is stable and transportable across the ant digestive system via aliphatic-PEG polymer technology (NC State University patent pending). 3) Evaluate the activity of injected VgR dsRNA versus aliphatic PEG dsRNA on Vg synthesis and egg laying in fire ant queens. 4) Evaluate effects of VgR dsRNA versus aliphatic PEG dsRNA provided in nectar or other food substances by colony feeding on Vg synthesis and egg laying in fire ant queens.
3. Progress Report:
This research directly supports and corresponds to in-house project Objective 3: Characterize semiochemicals through investigation of pheromone biosynthesis and surveillance methods, including the detection and treatment of incipient or low level populations; and Sub-Objective 3.1: Determine the function(s) of isolated neuropeptide and biogenic amine hormones, known in other insects to function in pheromone biosynthesis, development, and behavior modulation; and investigate function-interference for novel biologically-based control. ARS conducted bioassays utilizing fire ant workers to assess the effects of dsRNA in sucrose solutions provided by NCSU. Preliminary testing by NCSU suggested that fire ant workers would die within 3 days of exposure to this solution. Minimal mortality was observed in workers provided access to the dsRNA solutions. Agreement has terminated in 2013.