Pesticide science is faced with a growing demand for green or sustainable pesticide chemistries that offer reduced risks to human health and the environment. Efforts are placed on the development of new pesticides containing novel active ingredients and/or formulations from natural sources. These products continue to drive innovation and have been proven to present effective alternatives to conventional pesticides. The use of botanical extracts for management of arthropods can be traced back through centuries, and their biological properties continue to be explored in the scientific literature. Many of the terpenoid compounds contained in plant essential oil extracts are capable of eliciting strong inhibitory effects against arthropods in laboratory settings; however, effective delivery can pose many challenges in the formulation process including selection of active ingredients, emulsifiers, spreaders, and other necessary components. Recent data demonstrates that select botanical terpenes/plant essential oils can control public health pests under field and laboratory settings, but current products may not necessarily encompass the full potential of their active ingredients. Further research continues to improve on botanical formulations and offer new approaches, such as microencapsulation, for use in product development. These findings highlight improvements in the formulation of plant essential oil active ingredients, and provide support for using botanicals to control public health pests.