New York Natural Heritage Program
West Virginia White
Pieris virginiensis W. H. Edwards, 1870

Threats [-]
The West Virginia white is reported to be sensitive to forest fragmentation due to its poor colonizing ability and is threatened by the spread of the exotic plant, garlic mustard (Alliolaria petiolata) which may choke out stands of the the caterpillars' foodplant (toothwort, Dentaria sp.). In addition, while female butterflies will oviposit on garlic mustard, this plant is toxic to the caterpillars. Overbrowsing of toothwort as a result of very high deer densities is also a possible threat. Spraying for gypsy moth control has been and, at least in places, may continue to be a serious threat to this butterfly due to its occurrence in low population densities and its poor ability to colonize new locations (Cappuccino 1985). Logging practices which lead to the loss of stands of toothwort and destruction of toothwort stands from ATV use are possible threats in at least one region of New York (Taft 2006).

Conservation Strategies and Management Practices [-]
Employing forest management practices and ATV restrictions that do not contribute to the loss of toothwort stands would be desirable. Removal of garlic mustard where it occurs at or near West Virginia White colonies would be advantageous, but may only be practical on a small site by site scale.

Research Needs [-]
Research on deer densities in comparison to the distribution and abundance of toothwort may provide information useful for the conservation of West Virginia White colonies. Further research on dispersal tendencies may provide information useful in minimizing fragmentation of populations due to forest and other management practices.