Recently, an indigenous cerambycid, the red oak borer (ROB) Enaphalodes rufulus (Haldeman), reached epidemic populations in the Ozark National Forest of Arkansas. It has been a contributing factor to tree mortality in a widespread oak decline event. Factors regulating red oak borer population levels are largely unknown. On average, a red oak borer female can oviposit 100 to 200 eggs but within-tree larval populations are low. The significance of egg/neonate mortality on red oak borer populations has not been documented. Ants (Camponotus and Formica spp.) are among the most abundant potential predators in these forests, and the objective of this study was to develop molecular tools to determine if ants prey on ROB eggs and neonates. We sequenced a portion of the mitochondrial 16S rRNA gene of ROB, and developed polymerase chain reaction (PCR) primers to detect red oak borer DNA in the guts of Camponotus and Formica ants. Using laboratory-reared ants and ROB, we established that ROB DNA could be detected by PCR in ants that fed on ROB larvae or eggs. Furthermore, we screened ant populations collected from multiple forest sites before, during, and after the 2005 ROB emergence, and compared detection rates of ROB DNA in ants with the incidence of eggs and neonate larvae in the forest.