Manipulation of Solenopsis invicta virus-1 titers by RNA interference in red imported fire ant (Solenopsis invicta)

Solenopsis invicta Buren (red imported fire ant) is an economically important urban pest native to South America that has few natural enemies in the southern United States. Solenopsis invicta virus-1 (SINV-1) is a picorna-like single stranded positive sense virus only known to affect S. invicta.  RNA interference (RNAi) is a known regulator of RNA viruses in biological systems and is an emerging biologically based insect control method.  The purpose of this study was to increase, then decrease viral titers of SINV-1 in S. invicta colonies over a period of one month.  Manipulation of SINV-1 viral titers was attempted by first exposing S. invicta colonies to SINV-1 viral extract, then after fifteen days, exposing the same colonies to novel double stranded RNA (dsRNA) coded for SINV-1 viral capsid genes.  S. invicta colony mortality was monitored over the one month period, and significant increases and decreases in viral titers were noted. In conclusion, RNAi was used to manipulate viral titers of SINV-1 in populations of S. invicta.