Source: UNIVERSITY OF WASHINGTON submitted to NRP
WSDA KNOTWEED BIOCONTROL PROJECT
Sponsoring Institution
Other Cooperating Institutions
Project Status
COMPLETE
Funding Source
STATE
Reporting Frequency
Annual
Accession No.
0224635
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Jul 1, 2009
Project End Date
Jun 30, 2010
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIVERSITY OF WASHINGTON
4333 BROOKLYN AVE NE
SEATTLE,WA 98195
Performing Department
Restoration Ecology and Environmental Horticulture
Non Technical Summary
Two introduced knotweed species, Fallopia japonica (Japanese knotweed) and F. sachalinensis (giant knotweed), and the hybrid between the two, F. x bohemica (Bohemian knotweed) are invasive throughout most of the United States. These weeds displace native plants, destroy critical fish and wildlife habitat, and reduce recreational opportunities. The plant is fast spreading and difficult to control, especially in riparian zones. We will develop a classical biological control program against Japanese knotweed using natural enemies introduced from Asia. The overall goal is to determine suitability of several insects as biological control agents. Biological control is a cost effective, ecologically sound, and sustainable approach to managing widespread weeds. The project area includes all regions of North America where knotweed is invasive. It will be particularly beneficial to 7 U.S. States, including Washington, where knotweed is classified as a noxious weed. Biological control is most effectively applied in heavily infested areas and in areas that are difficult to access or treat by other means. Biological control will eventually benefit all land managers, agencies, counties, and private landowners throughout North America that are fighting knotweed invasions.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2152300113080%
2152300108020%
Knowledge Area
215 - Biological Control of Pests Affecting Plants;

Subject Of Investigation
2300 - Weeds;

Field Of Science
1130 - Entomology and acarology; 1080 - Genetics;
Goals / Objectives
1. Obtain and grow five test plant species. This will require travel to the East Coast and/or hiring of professional botanists where appropriate. 2. Ship critical plant species to CABI-UK (Centre for Agricultural Bioscience International) for testing of southern strain Aphalara itadori (UK collaboration). 3. Complete testing of northern strain of Aphalara itadori in the Oregon State University (OSU) quarantine. 4. Arrange for the collection and shipment of Aphalara itadori (central strain) and additional Ostrinia ovalipennis from Japan to the OSU Quarantine Facility. 5. Initiate testing of Ostrinia ovalipennis and Aphalara itadori (central strain). 6. Carry out genetic analyses to determine the frequency and distribution of various knotweed types. MILESTONES AND OUTPUT: A progress report on the biocontrol project will be submitted by November 30, 2009 and will include a summary of research and other activities, photographs of the biocontrol insects and their impacts on knotweed, and GIS locations of sampled and genetically characterized clones.
Project Methods
SUMMARY OF THE ENTIRE STUDY: We will follow government regulations and standard procedures in testing candidate biocontrol agents for knotweed to ensure that they will be safe to introduce. The steps in developing a new biological control program include: 1. Identifying the weed as a valid target. 2. Carrying out surveys for potential candidate biocontrol agents in the native range. 3. Developing the test plant list. 4. Host specificity testing of candidate agents. 5. Approvals and permitting. 6. Release and monitoring. Steps 1 through 3 have already been completed and host specificity testing of candidate biocontrol agents is currently in progress for two insects, with two additional insects to be imported and tested this year. When testing is complete, a petition for release will be submitted for review to the Technical Advisory Group. Final permitting is issued by USDA-APHIS and individual states. SPECIFIC METHODS FOR THIS SEGMENT OF THE STUDY: 1. Host Specificity and Impact Studies: Currently, we are working with two strains of the psyllid Aphalara itadori. We are currently performing host specificity testing on this insect in a quarantine facility located at Oregon State University in Corvallis, Oregon. To test the insects' ability to reproduce and develop on non-target plants, adult insects are caged onto individual test plants in a no-choice scenario. Five pairs of A. itadori are placed onto each plant for 5 days. At the end of 6 days, the adults are removed and the number of eggs on the plant recorded. The plants are kept watered and fertilized for sufficient time to allow any F1 adults to emerge (typically 6 to 8 weeks). The tests are carried out in replicate blocks which included one individual of each of the different test plant species plus one knotweed plant as a control. Each block of plants is replicated 6 times through time. To date, A. itadori has been tested on 17 of the 62 plant species to be tested. Ostrinia ovalipennis (to be imported in September 2009) will be tested using similar methods. To test the impact of candidate agents on target plants, each candidate agent will be caged onto 5 individuals of each target species: F. japonica, F. sachalinensis, and F. x bohemica. The species will be distinguished using flow cytometry. Five plants will be caged without insects as controls. Plant measures will be taken after one generation of the insects and again after two generations. 2. Genetic Studies: Leaf tissue samples of knotweed will be collected from infested areas throughout the Pacific Northwest. Our target will be 8 to 10 individuals from 10 to 15 different watersheds. Ploidy level analysis will enable us to distinguish species and hybrid forms, while DNA sequencing will allow us to differentiate between closely related plants to assess population diversity and determine the degree of sexual reproduction occurring in the population.

Progress 07/01/09 to 06/30/10

Outputs
OUTPUTS: We carried out research critical to the development of a biological control program for invasive knotweeds (Fallopia spp.). We obtained and grew the remaining test plant species needed to complete host specificity testing of the psyllid Aphalara itadori. We shipped plants to our collaborators at CABI Europe UK so they could complete testing of the southern strain of this insect. We completed testing of the northern strain of this insect in the Oregon State University Quarantine Facility. We arranged for collection and shipment of Ostrinia ovalipennis (moth) from Japan and initiated testing of this species. We collected knotweed tissue samples throughout Oregon and Washington for genetic analyses. Information about the knotweed project was shared with landowners, land managers, and the scientific community through public presentations at knotweed-focused meetings for the State of Oregon and Washington as well as invasive plant and biocontrol conferences on both the East and West Coast. PARTICIPANTS: Individuals: 1. Fritzi Grevstad (P.I.) University of Washington. 2. Paolo Sanguankeo, University of Washington. Partner Organizations: 1. University of Washington. 2. Washington State Department of Agriculture. 3. USDA Forest Service, Forest Health Technology Enterprise Team. 4. Oregon Department of Agriculture. 5. Oregon State University. 6. USDA Agricultural Research Service. Collaborators and Contacts: 1. Marshall Uno, Washington State Department of Agriculture. 2. Jennifer Andreas, Washington State University Extension. 3. John Gaskin, USDA ARS. 4. Richard Reardon, USDA Forest Service, Forest Health Technology Enterprise Team. 5. Richard Shaw, CABI Europe UK. 6. Robert Bourchier, Agriculture and Agrifood Canada. 7. Jim McIver, Eastern Oregon Agricultural Research Center, Oregon State University. 8. Eric Coombs, Oregon Department of Agriculture. 9. Peter McEvoy, Oregon State University. 10. Darrell Ross, Oregon State University. 11. Suguro Ohno, Okinawa Prefecture Agricultural Research Center. 12. Bernd Blossey, Cornell University. 13. Roy Van Driesche, University of Massachusetts. 14. Christian Marks, The Nature Conservancy. Training and professional development was provided one research technician to learn about methods in biological control host specificity testing. TARGET AUDIENCES: Target audiences include landowners, land managers, county and state agencies, other scientists, other regions and countries that have invasive knotweed as an environmental problem. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
We tested Aphalara itadori (north strain) on the five remaining test plants to bring the total number of plants tested to 69. We also collaborated with CABI-Europe-UK to complete testing of the southern ecotype of A. itadori. Both ecotypes were found to be very host specific. However, a very small number of individuals did developed on 3 non-target plant species. None of the non-target plants were able to sustain populations of either psyllid and no damage to the plants was detected. A petition for release has been written up for the north ecotype, but we will await remaining results for the southern ecotype before submitting the petition for review by the Technical Advisory Group on Biological Control of Weeds. The stem-boring moth (Ostrinia ovalipennis) was found to develop on and cause damage to several native and economically important plants and was therefore eliminated as a candidate biocontrol agent. Genetic analyses of knotweed tissue samples collected throughout Oregon and Washington indicated that (1) species identification based on morphological characters (leaf shape and leaf hairs) was generally accurate; (2) different river systems varied in which species of knotweeds they contained; (3) genetic variation was present within all river systems (no infestation was completely clonal). These outcomes are important steps toward developing and implementing a safe and effective biological control program for knotweeds.

Publications

  • McIver, J. and F. Grevstad. 2010. Natural enemies of invasive knotweeds in the Pacific Northwest. USDA Forest Service, Forest Health Technology Enterprise Team, 39 pp.