Management of Garden Symphylans (Scutigerella immaculata Newport) with Crop Rotation Tactics and Improved Sampling Methods

2004 Annual Report for SW03-033

Project Type: Research and Education
Funds awarded in 2003: $160,132.00
Projected End Date: 12/31/2005
Matching Non-Federal Funds: $19,851.00
Region: Western
State: Oregon
Principal Investigator:
Jon Umble
Oregon State University

Management of Garden Symphylans (Scutigerella immaculata Newport) with Crop Rotation Tactics and Improved Sampling Methods


This project was initiated in January 2004. A strategic planning meeting was held in January 2004 to develop a final plan of action. Much of this first year of work involved identification, establishment and evaluation of field plots at four experimental sites. Results from these plots provided strong evidence that the cultivation of potatoes led to significant decreases in garden symphylan populations. Trials investigating the specific mechanism leading to this decrease were initiated in the greenhouse and laboratory. Studies involving sampling methods are being conducted in order to develop practical specific guidelines for use by growers, researchers and private industry.

Objectives/Performance Targets

Objective 1: (Field Based Objective) Compare the effects of a weed-free potato cropping system and a potato cropping system that includes a weed host (of garden symphylans) on garden symphylan populations and the subsequent growth of a highly susceptible crop in the field.

Objective 2: (Greenhouse/Lab Based Objective) Screen additional crops for activity against garden symphylan populations

Objective 3: (Field Based Objective) Further develop the bait sampling method (used for assessing garden symphylan populations) so it may be used effectively by growers, researchers and private industry.

Objective 4: (Field Based Objective) Increase the ability to interpret garden symphylan population density estimates for management purposes by developing a damage curve and action thresholds for a highly susceptible crop.

Objective 5) Disseminate information about the biology, ecology and management of garden symphylan to a broad audience including conventional and organic growers, extension agents and private industry.


Objective 1 Accomplishments/Milestones: The first field season of trials related to this objective was very successful. At four infested sites (2 in Oregon and 2 in California), post-harvest garden symphylan populations were highest in “good host” monocrop treatment (either sweet corn or broccoli), intermediate in the intercrop treatment and nearly undetectable in the potato monocrop treatment. This trial provided strong evidence that cultivation of potato crops significantly decreased garden symphylan populations, and that this effect was fairly consistent over very different conditions (e.g. 4 sites with different soils, climates, tillage, timing of planting, irrigation, etc.). Continued work will include measurement of spring 2005 garden symphylan populations, and the subsequent growth of a highly susceptible crop.

Objective 2 Accomplishments/Milestones: In 2004, based on grower and researcher suggestions, 19 crops (+ intercrops) were selected and screened for activity against garden symphylans in a greenhouse trial. These included six potato varieties, eggplant, Sudan grass, broccoli, cauliflower, sweet corn, garden huckleberry, lettuce, French marigold, Mexican marigold, California poppy and potato intercrops. A population decrease of over 80% was observed in the six potato varieties included in the trial. This trial provided strong evidence that the observed population decrease in potato is consistent over a number of potato varieties, with variable alkaloid (plant defense compounds) compositions. None of the other crops screened decreased populations to the extent of potato. Laboratory trials are currently being conducted to evaluate the effect of isolated potato alkaloids on garden symphylan feeding and mortality. Future work will include continued screening crops and alkaloids.

Objective 3 Accomplishments/Milestones: In 2004, the bait sampling method was further developed by examining the relationship between this method and the considerably more time consuming standard soil sampling method. Studies are being conducted to identify the conditions under which the bait sampling method works best in order to develop specific guidelines for the use of the bait sampling method by growers, researchers and private industry.

Objective 4 Accomplishments/Milestones: The experimental plots for this objective have been identified. Crops will be planted and evaluated in the spring of 2005.

Objective 5 Accomplishments/Milestones: Information concerning the biology, ecology and management of garden symphylans was disseminated through a number of avenues including grower field days, grower and research meetings and featured articles in newsletters. Current work is underway to develop a garden symphylan website, which will include information for growers, private industry and researchers.

Impacts and Contributions/Outcomes

Continued development of the bait sampling method has led to increasing confidence in this method. This method has been adopted on a trial basis by a number of growers, researchers and private industry members. Further work with this method, including continued evaluation by end users, will aid in developing specific guidelines for this method, such as timing, number of samples and interpretation of sampling results. Reliable and economic sampling methods allow growers and private industry to make informed management decisions (e.g. intensity of tillage, pesticide applications, crop selection), and to evaluate the effects of management operations on garden symphylan populations. Continued crop rotation research (i.e. crop suitability for garden symphylan population development) will provide growers a management tactic to decrease garden symphylan populations.


Mendel Friedman
Research Scientist
USDA/ARS Produce Safety and Microbiology Lab.
Western Regional Research Center, 800 Buchanan Str
Albany, CA 94710
Office Phone: 5105595615
Rex Dufour
National Center For Appropriate Technology
California Office
Davis, CA
Office Phone: 5307568518
Jim Leap
Farm Operations Manager
The Center for Agroecology and Sustainable Food Sy
University of California at Santa Cruz
Santa Cruz, CA 95064
Office Phone: 8314593375
Jack Gray
Wintergreen Farms
89762 Poodle Creek Rd
Noti, OR 97461
Office Phone: 5419351920
Mark VanHorn
UC Davis Student Farm
University of California at Davis
Davis, CA 95616
Office Phone: 5307527645
James Todd
Willamette Agricultural Consulting Inc.
7555 Conifer St. NE
Salem, OR 97301
Office Phone: 5033787003
Mike Dickman

Dickman Farms
15829 Mount Angel Scotts Mills Hwy NE
Silverton, OR 97381
Office Phone: 5038456472
Peter Kenagy
Kenagy Farm
1640 NE North Nebergall Loop
Albany, OR 97321
Office Phone: 5419268038
Fisher Glenn
Extension Entomologist
Oregon State University
Department of Crop and Soil Science,
Ag & Life Science 3017
Corvallis, OR 97331
Office Phone: 5417375502
James Fisher
Research Entomologist
USDA/ARS Horticultural Crops Research Laboratory
3420 NW Orchard Ave.
Corvallis, OR 97330
Office Phone: 5417529456
Daniel McGrath
Extension Horticulturist
Oregon State University
Linn Co. Extension Oregon State University 104
4th Street SW
Albany, OR 97321
Office Phone: 5417376278
Tom Denison
Denison Farms
1835 NE Steele Ave
Corvallis, OR 97330
Office Phone: 5417524156
Michelle Vesser

Occidental Arts and Ecology Center
15290 Coleman Valley Road
Occidental, CA 95465