Larvae of Phyllophaga are destructive turfgrass pests in the south-central region of the United States. Methods to reliably identify immature Phyllophaga to species are not readily available. The objective of this study was to develop a molecular method that would reliably identify larvae of Phyllophaga inhabiting turfgrass ecosystems. Black light traps were used to collect adult Phyllophaga spp. from golf courses throughout Oklahoma in 2006. Phyllophaga larvae were obtained from sod production facilities and golf courses by removing sod using a sod cutter. Genomic DNA was extracted from larvae and traditionally identified adult specimens. The cytochrome c oxidase I (COI) region from each was amplified and sequenced. Based on phylogenetic trees constructed from COI sequence alignments, adults of Phyllophaga clustered into ten unique clades. To date, COI sequences from Phyllophaga larvae have fallen into three clusters, two of which correspond to species clusters from adults. These results suggest DNA sequences can be used as “barcodes” to distinguish between species of Phyllophaga larvae.