ARS | Publication request: SWALLOW-WORTS (VINCETOXICUM SPP.): A NEW WEED TARGET FOR BIOLOGICAL CONTROL

Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 10, 2005
Publication Date: February 13, 2006
Citation: Milbrath, L.R. 2006. Swallow-worts (vincetoxicum spp.): a new weed target for biological control. Weed Science Society of America Meeting Abstracts. no.126. [CD-ROM]. Vol. 46. Lawrence, KS: Weed Science Society of America.

Technical Abstract: Swallow-worts (Vincetoxicum rossicum, pale swallow-wort, and V. nigrum, black swallow-wort) are exotic, herbaceous, perennial, twining vines in the milkweed family (Asclepiadaceae). Pale swallow-wort is native to Ukraine and southwestern European Russia, whereas black swallow-wort is native to southwestern Europe. Both species are becoming invasive in North America, and can produce large, dense stands that reduce floral and faunal diversity and possibly redirect succession or interfere with forest regeneration. The primary infestations are found in New England, New York and Ontario. Swallow-wort grows in both full sun and shaded understories in a variety of natural, semi-natural, and agricultural settings. Reproduction and spread is primarily through the production of polyembryonic seeds. Mostly anecdotal data indicate little to no damage to swallow-wort by native arthropods (insects and mites), diseases or vertebrates such as deer. As an initial step in the development of a classical biological control program for swallow-worts, biweekly arthropod surveys were conducted in 2005 of pale swallow-wort infestations at multiple sites in New York. Plants from both open field and closed-canopy habitats were visually examined and dissected for arthropods. No insects or mites were observed feeding in the root crown, stems or pods. Few confirmed foliage-feeding insects or mites were found, many of which are known to feed on a broad range of plants. Spider mites were especially abundant at some locations due to a summer drought. In general no damage to pale swallow-wort was observed which may explain, in part, the increasing invasiveness of this exotic weed.