Oahu Invasive Species Committee (OISC)

  • A A A
  • Home
  • About Us
    • Who We Are
    • Where We Work
    • Meet Our Staff
    • Photo Gallery
    • Video Gallery
    • Awards
    • Contact
    • JOBS
  • Target Pests
  • Outreach & Education
    • Educational Resources
    • Community Outreach
    • Worksheets & Games
    • On-Demand Webinars
  • Volunteer
    • Join the Devil Weed Crew!
    • OISC Lyon Arboretum Volunteer Trip
    • Pūpūkea-Paumalu Volunteer Trip
  • Learn More
    • Common Invasives Info
    • How You Can Help
    • Hike Pono
    • News & Updates
      • News & Updates
      • OISC in the Media
      • Meetings
      • Reports
        • OISC Reports
    • Donate
    • JOBS
  • Report A Pest
  • Private Property Surveys

JOIN THE DEVIL WEED CREW

 


We’re so excited to launch this new community volunteer program! Being part of the crew will mean you will really get to know (and love getting rid of) this invasive plant.

Thumbnail Image for pdf linkWe are looking for people to commit to surveying Oahu trails and reporting their findings to OISC. There are also known areas on the island where Devil Weed is prevalent and large patches will need to be removed. We may reach out for help with these. This is a community led effort to help OISC determine the spread of devil weed on Oʻahu. ANYONE can participate anytime…just survey when/where you can!

  1. Simply pick a trail from our list.
  2. Look for devil weed on the trail.
  3. Report whether or not you find it using a free smart phone app.

Get started by heading over the Devil Weed Crew volunteer page!

Questions…Contact Erin Bishop, OISC Outreach Coordinator. E: oisc@hawaii.edu, C: 808-286-4616

Filed Under: Home Slider, News & updates Tagged With: #devilweed, #volunteer

Benefits of Devil Weed (AKA Siam Weed) Removal in Australia

“The removal of Siam weed… appears to have resulted in health benefits, with locals reporting a reduced incidence of asthma caused by Siam weed,” Dr Atkins, of the Western Australia Department of Agriculture and Food. Read the article HERE.

Siam weed, more commonly known as devil weed in Hawaii, is one of OISC top priority target species! If you see this plant growing along the road, in your backyard or on your favorite hiking trail, report it to OISC immediately at oisc@hawaii.edu or call 266-7994.

Filed Under: Blog, News & updates Tagged With: #devilweed

Devil Weed

Are you finding devil weed on your property? Pull plants and throw away in trash (NOT greenwaste).

Please report devil weed locations to OISC. Send photo and location to oisc@hawaii.edu or text 808-286-4616. 

 

This slideshow requires JavaScript.

Devil weed (Chromolaena odorata)

Family: Asteraceae

Devil weed (A.K.A Siam weed, bitter bush) is a well-documented pest and is considered one of the world’s worst 100 invasive species.   It is highly invasive and is on the Hawai’i State Noxious Weed List.   Devil weed received an extremely high score on the Hawai’i Weed Risk Assessment (HWRA), suggesting it has the potential to be exceedingly invasive in Hawai’i.

Description:

  • Herb or shrub with long rambling branches
  • Leaves are triangular shaped, opposite, with a toothed leaf edge.  Leaves are also limp with velvety hair and have a distinct turpentine smell when crushed.
  • The leaves have three thick veins shaped like a pitch fork, hence the common name “devil weed.”
  • Flowers are held in small clusters.  Pale purple to off-white, usually with distinct long stamens.
  • Fruits are tiny and have soft white hairs, which allow it to be spread on the wind or water. The hairs also act like Velcro, attaching themselves to anything passing by.
  • Native to tropical America.

Harm:

  • An aggressive colonizer of clearings and wet disturbed forests, creating dense thickets that impede growth and regeneration of native species.
  • Forms dense thickets 4-6 feet high.
  • Forms thick canopy that shades out other plants.
  • Releases toxins into the surrounding soil, reducing growth of other plants.
  • Toxic to livestock.
  • Forms monocultures, reducing biodiversity.
  • Consumes large amounts of water and negatively affect soil nutrient levels.
  • Can host pests and pathogens of kava/awa (Piper methysticum).
  • Each plant can produce 800,000 seeds each year, which are readily wind dispersed.
  • Sand-grained sized seeds are also easily spread by birds and other animals when they eat the fruit, and by people when dirt or mud containing the seeds stick to shoes, clothing, equipment, or vehicles.

On O’ahu

  • First detected in 2011 at the Kahuku Training Area/Kahuku Motocross Track, devil weed is now found in Kahana Valley, Pūpūkea and in ’Aiea. OISC is working to reduce these populations, but detections have been popping up across the island.
  • OISC’s management goal for devil weed was island-wide detection and eradication, however it has now had several long-range introductions to all sides of the island. It is now beyond OISC resources to eradicate island-wide.
  • Decontamination of hiking gear, bikes, and hunting gear between use is necessary to prevent it from spreading across O’ahu, as well as to other islands.
  • Begin your hikes, trails and hunts with clean gear. Don’t introduce hitchhiking weed seeds to new areas.
  • Early detection and removal are essential. Pull any devil weed plants out and throw away in garbage….NOT green waste.
  • For more information about devil weed detections….please call OISC at 286-4616 or email oisc@hawaii.edu
  • Join the Devil Weed Crew…volunteers that survey and remove devil weed from all Oahu trails. For more information, visit: Devil Weed Crew Page

Pest Alerts and Publications:

  • Devil Weed Rack Card
  • Devil Weed Pest Alert 
  • Chromolaena odorata Newsletter: Devil Weed in Hawaii

For more information, see:

  • Devil Weed Crew Oahu – Facebook Group
  • Devil Weed ID Video
  • Devil Weed Look-a-Likes
  • Hawai’i State-listed Noxious Weeds
  • Global Invasive Species Database; Chromolaena odorata

Filed Under: OISC Priority Pests Tagged With: #devilweed

News & Updates

OISC IS HIRING FOR FIELD CREW!

HISAM 2022 – Hawaii Invasive Species Awareness Month

BOLO LIST

Outreach & Education

  • Volunteer
  • Target Pests
  • Outreach & Education
  • News & Updates

About Us

  • Home
  • About Us
  • Who We Are
  • Meet Our Staff
  • Where We Work
  • Photo Gallery
  • Video Gallery
  • Awards
  • Contact
  • JOBS

Learn More

  • Outreach & Education
  • What You Can Do
  • Meetings
  • Schedule of Events
  • Early Detection
  • Donate

Stay Informed

  • Monthly Reports
  • Target Pests
  • Join OISC Email List
  • News & Updates

Contact Us

Oahu Invasive Species Committee (OISC)
Office: (808) 266-7994
Fax: (808) 266-7995

OISC Manager: Nate Dube
E-mail: oiscmgr@hawaii.edu
OISC Outreach Coordinator: Erin Bishop
E-mail: oisc@hawaii.edu

Pest Hotline: 808-643-PEST (7378)
Report a Pest Online

© 2022 Oahu Invasive Species Committee (OISC) • Sitemap • Log in

 

Loading Comments...