Next generation sequencing approach to molecular gut content analysis of red imported fire ants (Solenopsis invicta)

We used Next Generation Sequencing (NGS) of fire ant (Solenopsis invicta) brood gut content to reveal the role of fire ants in natural and agricultural food webs. NGS can broadly unravel trophic interactions by amplifying total gut/ body DNA of a predator/consumer, using general primers to produce a snapshot of a diversity of consumed prey. NGS promises to radically improve our understanding of trophic linkages and replace the traditional PCR/ sanger sequencing based techniques that are limited by primer specificity and a narrow focus on a small set of prey. The NGS gut content analysis was performed on DNA amplicons from field collected fire ant brood. We collected S. invicta brood from multiple field sites in Texas. We chose to collect 4^th instar brood as they process solid food for the colony and retain a meconium that potentially extends the DNA detection window.  We extracted and amplified DNA using a CO1 primer set and a mitochondrial 16s primer set.  Samples were sequenced on an Illumina HiSeq, and the resulting reads were processed and analyzed to identify unique taxa.  We found that fire ant colonies consume a wide range of prey including arthropod herbivores and predators, but that fire ant diet varies by site and habitat type.