Cochineal insects (Dactylopius: Dactylopiidae: Coccoidea) are strict cactus parasites that are both pests of agriculture, commercially grown themselves, and useful biological control agents. Any genetic framework for this genus is completely lacking at onset of this project. Work here is focused on species delimitation within the genus Dactylopius. In the first chapter I present a morphological description of a new species of Dactylopius from the Chihuahuan Desert. In the second chapter I delimit the cochineal insect (Dactylopius coccus) using mtDNA data using a variety of population genetic and phylogenetic approaches. Third chapter I use mtDNA and nuclear coding and non-coding DNA to delimit the other species found within the genus sampled from across their recorded geographic and host-plant range.