Exotics Plant Species Report
Cape Ivy Funding Needed
December, 1999

Cape ivy (Delairea odorata) formerly known as German ivy (Senecio mikanioides) is a highly invasive non-native weed of coastal California. It is rated List A-1 (most invasive) by the California Exotic Pest Plant Council (CalEPPC). Cape ivy infestations occur from San Diego to southern coastal Oregon in riparian forests, coastal scrublands, grasslands, Monterey pine forest, coastal bluff communities, and seasonal wetlands. Cape ivy is established and highly problematical in Golden Gate National Recreation Area, Point Reyes National Seashore, Santa Monica Mountains National Recreation Area, Redwood National Park, Big Basin State Park, Hearst San Simeon State Park, Mt. Tamalpais State Park, Van Damme State Park, Jughandle State Park, and on U.S. Forest Service lands along the Big Sur coast. In San Diego County, Cape ivy runs the length of Bonsall Preserve with 100% cover in the southern part of the preserve and populations have been reported from Reidy Creek in Escondido, the Elfin Forest area, Torrey Pines State Park (and feeder streams), the Lake Hodges area, Sabre Springs, Marian Bear Natural Park, Tecolote Canyon, and the Jamul area. Cape ivy tends to grow vigorously in physically challenging environments such as streamside thickets, steep slopes and poison oak habitat. It is extremely difficult to control by conventional mechanical and chemical means when already well established in an area.

Development of a safe and effective classical biological control program for Cape ivy was proposed and a biological control research project was initiated two years ago. A research team was assembled in South Africa (the native habitat for Cape ivy) and the first year was funded by the National Park Service, the David and Lucile Packard Foundation, the California Native Plant Society (state and four local chapters-note the San Diego chapter was not one of those local chapters), the Golden Gate National Parks Association, the California Department of Parks and Recreation, and a major private donor. The third year of the project requires $63,000 with approximately $35,000 already having been identified for the project (a CNPS individual member, California Department of Parks and Recreation, CalEPPC, CNPS state organization, and another CNPS individual member).

To date, more than 400 insect species have been collected and most have been identified. Four candidate species appear suitable for classical biological control testing as they appear to be insects specialized to use Cape ivy: a defoliating caterpillar, a stem-boring moth, a stem-galling fly, and a leaf beetle. The main focus in year three will be both field and laboratory work concerning host specificity testing. There is a great advantage to doing the evaluation in South Africa where native plant species closely related to Cape ivy can be inspected in the field and tested under non-quarantine conditions in the laboratory to determine if they are being used by the candidate species. If the candidate insects do not oviposit or develop on closely related plant species, they will be considered suitable for further specificity testing, evaluation, and possible release in the United States (hence the need for seeds of Senecio ganderi to cultivate this sensitive species of San Diego County for host specificity testing). The local chapter is considering making a $2,000 donation for this work and we ask chapter members to contribute to this project. As in prior years, CalEPPC will serve as a fiscal agent to receive non-federal contributions of funding to the project. CalEPPC is a California not-for-profit organization qualified to receive tax-deductible donations.

Failure to fund the team in the third year will mean the collapse of the program and loss of much of the work of the first two years. Money is needed by the end of 1999 but it is probable that the actual receipt of money could be delayed until April if we can absolutely guarantee its arrival. Unfortunately, promises and hoped for grants are not enough. If you know of individuals, organizations, or agencies that may have an economic, recreational, or aesthetic interest in controlling the plant, please forward their information to Jake Sigg, CNPS, San Francisco, CA 94122 (415) 731-3028 (T), jsigg@pacbell.net or Dr. Joe Balciunas, Biological Control of Western Weeds Quarantine at USDA-ARS, Western Regional Research Center, 800 Buchanan Street, Albany, CA 94710-1105 (510) 559-5975, joebalci@pw.usda.gov. For more detailed information about the project you can contact Cindy Burrascano locally (619) 421-5767 or CynthiaGB@aol.com.

-- Cindy Burrascano

The National Park Service has a good photo of Cape Ivy.

Other Resources:
CNPS Invasive Exotics (state site)
CNPS Policy on Invasive Exotics
California Exotic Pest Plant Council