In this project we will focus on the cattail mosquito, Coquillettidia perturbans. It has been suggested that the Coquillettidia perturbans species of mosquito actually exists as two cryptic species, a potentially common phenomenon in the insect world. A cryptic species is when two or more species that were classified as one species are proven to not be the same species regardless of their similarities. We will use DNA barcoding as a method of differentiation between possible cryptic species by investigating a section of the mitochondrial gene COI (cytochrome oxidase subunit I). We will do this by extracting DNA from Coquillettidia perturbans samples provided by the Suffolk County Department of Health, extracting DNA from these samples, performing PCR to amplify the COI gene, and performing gel electrophoresis to determine if the PCR reactions have worked for each sample. It has been shown that differences of above 2% in the DNA sequence of the COI gene can distinguish between species.