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Delivery system using sodium alginate virus loaded pellets to red imported fire ants (Solenopsis invicta, Hymenoptera: Formicidae)

Tufts, Danielle M., Spencer, Kyle, Hunter, Wayne B., Bextine, Blake
Florida entomologist 2011 v.94 no.2 pp. 237-241
RNA interference, Solenopsis invicta, baiting, biological control, double-stranded RNA, fire ants, foraging, longevity, microencapsulation, pellets, reverse transcriptase polymerase chain reaction, sodium alginate, toxins, virion, viruses
Microencapsulation as a delivery mechanism of SINV-1 and other molecules such as dsRNA, offers an approach to Solenopsis invicta Buren management that is target specific and fitscurrent approaches to baiting ants with toxins and/or RNA-interference. The delivery method presented here targets ground dwelling, foraging ants with an ant-infecting virus which is specific to the genus, Solenopsis. Endemic ant-infecting viruses, like S. invicta viruses (SINV-1, SINV-2, and SINV-3) are being evaluated for efficacy in S. invicta population suppression. In this study, SINV-1 (TX5 strain) was extracted from S. invicta colonies and microencapsulated in sodium alginate pellets. Pellets containing extracted whole virions were offered to confirmed non-infected S. invicta colonies. Colonies were sampled every 5 d and tested by reverse transcription polymerase chain reaction (RT-PCR) for presence of vira lRNA. The longevity of control and viral pellets were also evaluated. Within 30 d, post-feeding of virus, 35% of S. invicta colonies acquired SINV-1 infection (P= 0.03). Thus, microencapsulation as a delivery mechanism was successful to deliver SINV-1 toS. invictacolonies. Future incorporation of this economically affordable method can be implemented to deliver biological agents for specific ant species and to augment current approaches that bait ants. While a virus was used to demonstrate delivery, an adequate and affordable virus production system still needs to be developed before a viral strategy can be adopted as a tool for biological control of fire ants.