Biological control (biocontrol) agents are organisms used to control pest species. Insect biocontrol agents are highly specific, controlling one host species or species closely related to the host. Teleonemia scrupulosa was introduced throughout Hawaii as a biocontrol agent for the invasive plant Lantana camara (lantana). T. scrupulosa was selected as a suitable biocontrol for lantana based on field observations. Although host-specificity tests were not conducted before the release of the insect, T. scrupulosa successfully controlled lantana throughout Hawaii with the aid of other introduced biocontrol agents. Years after the initial introduction, there were observations of T. scrupulosa feeding on a Hawaii native plant, Myoporum stellatum (Oahu naio), in the absence of the host lantana. Previous research has shown T. scrupulosa is able to feed and reproduce on M. stellatum. Understanding the causes of non-target attacks by biocontrol agents is essential for improving the predictive power of host-specificity testing for insect biocontrol agents. This project builds on previous research by understanding the rare case of a non-target attack by T. scrupulosa on a distantly related plant, M. stellatum, by investigating intraspecific genetic variation within mtDNA genes COI and COII of three T. scrupulosa populations. Results have shown slight genetic variation within one T. scrupulosa population consistent with the existence of multiple introduced populations. This knowledge may aid in the determination of a possible host shift of T. scrupulosa in Hawaii due to possible co-adaptive traits developed after introduction or genetic variation allowing certain T. scrupulosa populations to utilize other plant species.