Four years ago, we beat back an invasion of zombie spaghetti; but this crawling menace has returned. Back in 2006, a leafless, stringy, yellow parasitic vine, Japanese dodder, was discovered on host plants and trees in several Sacramento County neighborhoods. At the time, this invader was stopped; at least that was the hope.
The latest find was this month near Clarksburg, in Yolo County, adjacent to the Sacramento River. One official surmised that dodder seeds or plant parts were spread there deliberately, in order to harvest the mature plant for medicinal purposes. Currently, the Yolo County Agriculture office is working with the California Department of Food and Agriculture (CDFA) to come up with an eradication plan.
Japanese dodder, also called strangleweed, resembles contorted spaghetti and is a non-native aggressive species that is spread by seeds, stems and roots, and can quickly move to other host plants. Once a seed or growing tip finds a host, it sends root-like structures called haustoria into the host's limbs, sucking out water and nutrients. Severe infestations can kill host plants. Japanese dodder attacks full-grown trees including many of our California native and agricultural fruit trees. And it is one tough seed. Dodder seed can survive soil solarization, a method for killing weeds using a clear, plastic tarp and the sun’s heat. Why? Probably because of its hard seed coat.
Japanese dodder, Cuscuta japonica, is native to Asia. It will also attack and cover just about any garden plant, especially ornamental shrubs and fruit trees, with a preference toward citrus. However, Japanese dodder also can parasitize annuals, perennials, and trees such as oaks and willows. Contact your county agricultural commissioner to receive proper identification and help with control.
So far, control of Japanese dodder is through mechanical removal of the host, but because stem fragments act as propagules, only agency officials should remove Japanese dodder at the time. This will ensure correct vegetation disposal and prevent spread.
At the CDFA website, you will find this Japanese dodder FAQ:
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| Japanese Dodder |
What does Japanese dodder look like?
Vibrant yellow-green to gold leafless vine.
Robust, round, twining stems that are fleshy and/or stout (1 – 3 mm in diameter), possibly with small red to purplish spots.
Mature stems are comparable in size to cooked spaghetti.
Unlikely to have flowers (normal flowering season is August – October).
If flowers are found, they will be small (3-7 mm), sessile, pale yellow to cream colored, in short, dense axillary spikes.
Unlikely to have flowers (normal flowering season is August – October).
If flowers are found, they will be small (3-7 mm), sessile, pale yellow to cream colored, in short, dense axillary spikes.
Infestations often large, spreading, and web-like. Frequently covers large shrubs and small trees.
Where is it likely to be found?
Currently, infestations have been found in the counties of Alameda (Oakland), Butte (Oroville), Contra Costa (El Cerrito, San Pablo, Pinole and Richmond), Fresno (Fresno), Merced (Merced & Winton), Shasta (Redding), Sutter (Yuba City), Tulare (Visalia), Yolo (West Sacramento), Yuba (Olivehurst and Marysville), Sacramento (Sacramento), and Los Angeles (Los Angeles).
Infestations are highly correlated with Asian immigrant residential neighborhoods.
Possibly near roads and freeways.
Probable hosts include fruit trees and ornamental shrubs, although it can occur in native plants such as willows and oaks.
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| Japanes dodder wrapped around fennel |
Native dodders are typically orange.
Japanese dodder has thick, robust stems.
Japanese dodder has thick, robust stems.
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| Native dodder (CDFA photos) |
Native dodder stems are usually more thread or string-like.
Japanese dodder infestations are typically large, entirely covering shrubs or trees.
Native dodder infestations are likely to be smaller, infecting nonwoody plants or small shrubs.
Japanese dodder has been found in residential areas and ornamental plantings.
Native dodders are found in wildland areas or crops.
Japanese dodder is unlikely to be found in hot, dry desert climates or at high altitudes.
If you find an infestation:
Do not attempt to remove or control it with herbicides.
Document the Location with GPS coordinates.
If GPS is unavailable, write down the address and/or nearest cross streets and/or directions to the site. Be specific!
Identify the host plant(s), if possible.
Take pictures.
Call or contact your County Ag Commissioner's office or the CDFA. They may ask you to collect a sample.
In Yolo County, contact the Ag office via their website or telephone 530-666-8140.
In Yolo County, contact the Ag office via their website or telephone 530-666-8140.
More information on dodder is available on the California Department of Food and Agriculture website.
In Sacramento County, Suspected Japanese dodder sightings may be reported to the Sacramento County Agricultural Commissioner's Pest Hotline at (916) 875-6744 (recording 24 hours a day),
Quite interesting, when I lived in New Mexico we used to collect native dodder to use to dye cotton and wool before spinning and weaving. It is a very different, but way cool plant.
ReplyDeleteWe have an invasions of Japanese Dodder in our live oaks (Virginia oaks) in Florida. I can find no information on line about eradication in Florida. I see this post dates from 2010. Has there been progress in eradication in trees since then in California? Thank you.
ReplyDeleteUnfortunately, hand eradication is still the primary means of removal. https://www.cdfa.ca.gov/plant/ar/ipc_jd.html
DeleteThank you for the information, however disappointing. The trees are so tall, we cannot get to the top to remove.
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