Proceedings of the Sixty-first Annual Meeting of the Northeastern ...

97
RAPID RESPONSE TO THE INVASIVE VINE, BUSHKILLER, IN NORTH CAROLINA.
R.J. Richardson, A.M. West, and A.P. Gardner, North Carolina State Univ., Raleigh,
NC.
ABSTRACT
Bushkiller (Cayratia japonica (Thunb.) Gagnep.) is an aggressive, perennial vine
in the grape family (Vitaceae). Prior to 2005, this exotic species was only known to
occur in North America in the Texas to Mississippi area. Bushkiller is somewhat similar
in appearance to Virginia creeper (Parthenocissus quinquefolia (L.) Planch.). Both
species bear leaves of five leaflets with serrated margins. However, bushkiller is
herbaceous with a terminal leaflet larger than the other four leaflets providing a distinct
appearance. Tendrils are opposite from leaves and do not have adhesive discs like
Virginia creeper. The flowers are small yellow clusters and have not produced viable
seed in North Carolina. In August 2005, an unknown weed sample was submitted to
North Carolina State University for identification. This plant sample was soon
recognized as bushkiller (Cayratia japonica (Thunb.) Gagnep.) and confirmed by
herbaria samples. Local extension agents and homeowners were immediately
contacted to arrange a site visit. By September, scientists from NCSU, APHIS, and
USGS had visited the site in Winston-Salem, NC, to assess the situation. A small task
force was then created to develop and execute an eradication plan. The task force
obtained limited funding to begin eradication procedures in 2006. The plan consisted of
foliar applications, cut-stem treatments, and handweeding of the infested site.
Greenhouse trials indicated that triclopyr was the most efficacious herbicide on
bushkiller with adequate selectivity for use on the infested site. NCSU personnel,
county extension agents, and local volunteers participated in the eradication efforts with
support of the affected homeowners. While vigor and density of the bushkiller
population has been reduced, treatments will need to be continued at least through
2007 before complete eradication could be possible. Extension agents and the general
public have not reported this species at any other sites in North Carolina.
79