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Brief Reports

Projects in Progress List:

Glassy-Winged Sharpshooter,      Millennium Grove Avocado Demonstration,   Pepper Weevil,      Walnut Husk Fly,       Habitat Enhancement Training,
Red Gum Lerp Psyllid,      Southeast Asia Project,
Biological Agriculture Systems in Cotton,        Compost Tea Workshop,
Youth Seminars,       Ventura River Trail Insect Attracting Garden

new  Reading Weeds book (in progres)

Past Events List:

Soil and Compost Ecology Seminar,   
Choosing Borders and Interplantings for Natural Control of Pests,
Fighting New Pests of Avocados Biologically

Projects in Progress

Biological Control of Glassy-Winged Sharpshooter (GWSS)

PROBLEM: GWSS has spread rapidly in Ventura and Santa Barbara counties threatening citrus, avocado, and grapes.

SIGNIFICANCE: Tree crops are rendered unmarketable by heavy frass. Grapes are killed by Pierce’s disease vectored by GWSS. A variety of efforts, including genetically engineered resistant cultivars, parasite mass rearing, etc. are being heavily funded. However, the potential to leverage the effectiveness of the natural or mass-reared sharpshooter enemies by habitat manipulation has received little attention as a potential suppressive technique.

STRATEGY: Continue to observe ecology of GWSS and associated natural enemy complex and potential trap crops, report findings in the community and look for growers willing to participate in a demonstration.


Confirmed the potential role of natural enemies in GWSS suppression:

Observed 95%+ rates of parasitism in some Ventura County orchards.

Observed nearly universal association between green lacewing and GWSS, including voracious feeding by lacewing larvae on egg masses.

Confirmed potential for certain plant species to differentially attract the pest.

Observed potential trap crops including non-egg-laying aggregations on fennel and tree tobacco.

Observed strong preference for corn as an egg-laying site.


Millennium Grove Avocado Demonstration

PROBLEM: Spray oriented critics maintain that biological control is compromised over large areas of the Santa Clara River Valley by dust plumes originating at the Toland Sanitary Landfill.

SIGNIFICANCE: Road dust is frequently noted as interfering with biological control on crops located within a few yards of the dust source. Regional dust effects, operating over a scale of miles, have never been specifically investigated. Biological control monitoring at the landfill carries implications wherever agriculture lies adjacent to large-scale earth-moving operations.

STRATEGY: Create a biological pest control demonstration on landfill- owned buffer zones where exposure to putative dust sources is greatest. Successful biological control at the landfill will serve the dual purpose of satisfying critics on the regional dust issue and providing a no-spray demonstration to the local community.

ACCOMPLISHMENTS: Launched a monthly insect monitoring program under contract with landfill operators. Demonstrated that most "dust-induced" insect outbreaks in the landfill buffer zones are actually ant-induced and disappear as ants are brought under control. Advising on biological management of persea mite in the newly planted 18 acre avocado orchard and on habitat manipulation to support the natural enemy complex—including mulch, cover crops, insectary plants, etc.

Biological Control of Pepper Weevil

PROBLEM: Pepper weevil is the only economically significant pest for organic pepper farmers in Ventura and Santa Barbara counties.

SIGNIFICANCE: Only chemically managed farms are able to participate in the lucrative late season pepper market by using a heavy weekly pesticide spray schedule.

STRATEGY: Pursue two parallel strategies with regard to this pest: release of pepper weevil parasite Catolaccus hunterii in farmer/cooperator fields, and mass-rearing of a locally adapted parasite for expanded augmentative release.

ACCOMPLISHMENTS: Secured USDA approval for parasite introduction. Undertook program of weekly parasite releases in cooperation with University of Florida researcher Dr. Dave Schuster during 1999 season. Verified short-term survival and spread of released parasites. Gathered tentative evidence of parasite reproduction. Establishing culture of factitious host Callosobruchus macculatus to allow rearing of locally adapted parasite strain. Establishing parasite culture for study and release on local farms as numbers permit.

Walnut Husk Fly Project

PROBLEM: Walnut husk fly is the key pest in much of California’s walnuts. As growers find alternatives to broad-spectrum pesticides, such as against codling moth, naturally occurring beneficials drive all pests below the level of economic damage with exception of walnut husk fly.

SIGNIFICANCE: When growers spray to control this pest, they disrupt the natural enemy complex. The disruption forces them to rely on toxic materials to control other walnut pests in a "spray for one; spray for all" cascade of effects. By maintaining bare ground in walnut orchards, a complete soil food fails to develop and soil-dwelling husk fly predators are too few to suppress the pest. The situation is complicated by the harvesting requirements of walnuts. Many cover crops could potentially enhance the soil food web. Unfortunately, these same plants may interfere with collecting. Ground cover may encourage mold on fallen nuts because of greater ground moisture.

STRATEGY: Build a complete soil food web so that the ground stage of the husk fly is attacked by natural enemies. Select and determine how to manage ground covers that feed the soil organisms without impeding harvest. Compare husk fly damage with neighboring orchards.

ACCOMPLISHMENTS: A nine-acre grove in the Santa Ynez Valley was planted with a variety of perennial and self-seeding annual grasses and legumes to determine which species established and could be managed. At harvest time, a combination of low mowing and natural drying provided a substrate compatible with harvesting requirements. Mounds of horse-stall bedding straw were placed near each tree to encourage spiders, predator beetles, predator mites, fungi, etc. Husk fly damage has been low during several years of the study, but unusual weather and a variety of other circumstances complicate the interpretation.

Habitat Enhancement Training Project

PROBLEM: Widespread use of pesticides continues because growers lack information about ecologically based alternatives.

SIGNIFICANCE: Although growers are typically aware of insectary reared beneficials, they lack knowledge of habitat manipulation required for full effectiveness of released and native beneficials. There are few trainers able to impart this information to growers and few demonstration farms where they may see the effects of habitat enhancement. More experience is needed about how farmers choose and manage appropriate habitat enhancements.

STRATEGY: Recruit interested farmers in Santa Barbara and Ventura counties. Work with them to choose and manage hedgerows and cover crops that support predators and parasites to realize the full potential of ecologically based pest management. These farmers will become trainers by successful example and their farms serve as demonstrations for other farmers, pest control advisors, etc.

OUTCOME: The California Energy Commission and the Environmental Protection agency funded the project, running from 1997 through early 2000. During the course of the project six cooperating farmers who are leaders in their localities planted cover crops, strips of flowering plants in row crops, and perennial hedgerows along farm roads to attract beneficial insects. Significant pesticide reduction was realized at all participating farms. Through farm tours, lectures and printed material, approximately 1700 agriculture professionals were exposed to ecologically based pest management. The book "Helping the Good Bugs Win" soon to be published is a legacy of the project and an attempt to extend these concepts in wider and wider circles.

Biological Control of Red Gum Lerp Psyllid

PROBLEM: Lerp psyllid, Glycaspis brimblecmbei, has spread rapidly throughout California’s landscape red gum Eucalyptus.

SIGNIFICANCE: Lerp honeydew creates problems and trees are threatened. Natural enemies attack but fail to control. Most people do not appreciate the importance of classical biological control projects to restore natural enemies with pests and do not understand the role of ant interference in biological control. They can learn these fundamental principles through this example.

STRATEGY: Demonstrate improved biological control by reducing ant interference, pursue collaboration with the University of California regarding production and release of imported parasites and provide education to the public about the case.

ACCOMPLISHMENTS: Educational materials have been developed, assistance was provided for a science fair project that won several prizes and community attention.


Southeast Asia Project

Three of the four countries of SE Asia, Cambodia, Lao PDR, and Thailand have been selected as potential sites for implementation of the Farmer Field School (FFS) project. The goal of this project is to transfer the concepts and skills necessary to implement the "Five Features of IPM" (formulated by Everett Deitrick in 1969) to the farming communities of SE Asia.

The five principles can be summarized as: 1. Avoiding use of disruptive pesticides whenever possible, 2. Building beneficial refuges including strip and trap crops, 3. Monitoring insect ecology, 4. Developing cultural practices that take advantage of the known behaviors of both pests and beneficials, and 5. Release of beneficial organisms. While these principles are included in the approach of many existing IPM training programs it is our emphasis on an ecological basis for pest management that we feel provides the best chance for sustainable insect pest management practices while maintaining farm production at modern levels of excellence.



This project seeks to include rural subsistence farmers and commercial producers, including greenhouse production. Target groups will be formed through networking with farmer associations, commercial production associations, local NGO’s, educational institutions and the international community.


Training programs will be focused on existing projects wherever possible, providing tools and techniques for increasing the ecological component of these efforts.

Resource materials for field identification of pests and beneficials, such as photos, preserved samples, and microscopic analysis will be provided in a format that enables trainees to learn about insects as communities of pests and beneficials.

Networking opportunities will be improved as necessary so that trainers can send collected insect samples to the Dietrick Institute for identification via either the internet or mail. Inputs may include computers, computer microscopes, and internet connection support where needed.


We understand that transferring the concepts of IPM requires long-term support of practitioners so there will be a strong emphasis on providing access to the internet and training of trainers where to find local and international assistance.

The training methodology most appropriate for this project is one that allows the trainee to become deeply involved in a hands-on way. One approach,  called the "Experiential Learning Cycle",  emphasizes group activities and sharing of knowledge where the trainer becomes a facilitator of the learning process rather than a presenter of information.  This is the training model we hope will be used by project partners and one we will support through curriculum development and training of trainers.  For a full report click here.

Project Leader:  David A. Loring

Biological Agriculture Systems in Cotton (BASIC)

PROBLEM: Kern County accounts for 27% of the state’s cotton pesticide use. No pesticide reduction program for cotton exists in the southern Central Valley. The price of cotton is so low that unless inputs are reduced and/or organic premiums obtained, cotton-growing will stop being economically viable in the region.

SIGNIFICANCE: In California, cotton is the single largest user of EPA category 1 and category 2 pesticides. Participants in the BASIC Project (Biological Agriculture Systems in Cotton) in the northern San Joaquin successfully reduced pesticide usage by 83%. Our organization is uniquely qualified to extend the US EPA BASIC Project to Kern County. There are no local consultants with the experience to teach Kern County cotton growers how to get off of systemic pesticides and transition to ecologically based pest management.

STRATEGY: Recreate regional biological crop systems by establishing beneficial insect reservoirs on six farms, minimum 30 acre blocks. Plant and manage borders and break-strips of unsprayed alfalfa, perennial draught-resistant borders, and annual insectary plants within crop rows. Build from the experience of Everett Dietrick, our senior entomologist, who researched the relationship of alfalfa hay management to biological control in neighboring crops and has experience taking California cotton out of spray in the 1960’s. Recruit local independent pest control advisors to a management team. Compare pesticide use reduction before and after first season of use of biologically intensive strategies.

ACCOMPLISHMENTS: Cooperative agreement forming with the Sustainable Cotton Project and Rodger and Sandy Sanders as cooperators. A project description, job description for a local coordinator and grower cooperator agreements are drafted, and first year strategy outlined for the Sanders farm.

Compost Tea Workshop

PROBLEM: Research points increasingly to the use of microbial innoculants to foster plant nutrition and combat pathogens (See USDA- ARS’s Kuykendall’s recent findings). Growers and horticulturists need to be aware of these findings and taught correct mixing and application of bacterial/fungal preparations.

SIGNIFICANCE: Compost teas can help retain nutrients in the rhizosphere that would otherwise be leached into ground water. Others form protective sheaths around root hairs or produce exudates that block pathogens from attacking the crop. The net effect of these preparations is to reduce fertilizer and pesticide use.

STRATEGY: Conduct compost tea seminar with a discussion of underlying science and demonstration of mixing and application. Speakers will include: John Lafleur, Ganna Walska Lotusland in Santa Barbara; John Agulia, ABC Organic Research Foundation; and Michael Alms, Growing Concern.

Youth Seminars

PROBLEM: Youth from age nine and up are interested in insect ecology, but their teachers do not have the knowledge or resources to teach them.

SIGNIFICANCE: Early introduction to biological control, building on children’s natural fascination with "bugs", will make future farmers and consumers more conversant with ecologically based pest management.

STRATEGY: Develop a youth oriented introduction to ecologically based pest management and present two seminars to 4H groups, Future Farmers of America, etc., offer the lesson plan and results on our web site. Organize a sustainable gardener competition for youth as part of the Ventura County Fair.

ACCOMPLISHMENTS: Hosted the Entomology Club of the Bardsdale 4H Club. Gaining experience, resources and contacts to further develop the project.

Ventura River Trail Insect Attracting Garden

PROBLEM: Few sites exist where local growers may examine the various plants that are candidates for inclusion in insectary habitats. Dietrick Institute staff lack opportunities to study species and varieties, rates of growth, details of establishment and maintenance, and what kinds of insects are associated with them.

SIGNIFICANCE: Plantings in the easement bordering our facility will make study and demonstrations possible. In addition, the Ventura River Trail is a high use foot and cycle path. By planting an insectary habitat strip, accompanied by explanatory signs, hundreds of people passing by each week can be introduced to information about biological control.

STRATEGY: Plant and maintain beneficial insect refuge demonstration garden along a new hike/bike easement on our property with explanatory signs.

ACCOMPLISHMENTS: A 50-yard strip fronting the trail has been cleared, mulched, some planted in barley and treated with microbial teas to try to break down years of accumulated herbicides from the former railroad bed. Local government installed a rail fence and agreed not to apply more herbicides to the area. Drawings and plant selection are in process while we look for local government help with irrigation lines and signage.

Past Events

Soil and Compost Ecology Seminar

PROBLEM: Recent findings by soil scientists, potentially important to farmers, are not available; the knowledge is confined to the academic community.

SIGNIFICANCE: Those who work with synthetic fertilizers frequently point out that plants cannot tell the difference between a nitrogen atom from their product and one derived from compost. Although correct in a trivial sense, this fact is used to imply that no substantive differences exist between synthetic and natural fertilizers. The latest scientific findings have uncovered profound differences in the way these two fertilizer regimes affect soil bacteria and fungi. The research further reveals that altered microbial populations dramatically influence every other organism inhabiting the soil, including crops and crop pests, and can lead to the success or failure of transitions away from chemical farms and establishing biological control. Farmers interested in doing on-farm experimentation including comparisons of microbial bioassays before and after interventions and on the best and worst parts of their farms need guidance how to collect samples and understand the results.

STRATEGY: Host a seminar at which Dr. Elaine Ingham summarized current knowledge of soil microbial populations and their impact on water and nutrient retention, prevention and mitigation of soil borne disease, relationships to soil arthropod pests, etc.

OUTCOME: The seminar, conducted in October 23, 1996, attracted an audience of 90 growers, farm advisors, and other agriculture and urban pest management experts. Dr. Ingham addressed the above need using simplified concepts based on categorizing microbes into functional groups. She explained the mechanisms by which conventional chemical agriculture interferes with the normal functioning of the soil food web forcing continued applications of synthetics elaborating on an example in Central Coast strawberry coast. Her dynamic style kept most of the crowd attentive well past the scheduled close of the meeting.

Choosing Borders and Interplantings for Natural Control of Pests

PROBLEM(S): Growers often view biological control as roughly equivalent to "spraying with bugs". However, successful biological control often depends on the presence of a supportive habitat for mass-reared or naturally occurring beneficial insects in and around the crop. We were looking for cooperating farmers with good potential for success in demonstrating beneficial insect habitats for pesticide use reduction.

SIGNIFICANCE:  To attract and maintain populations of beneficial insects, the farm must provide for all of their needs. The requirements may include alternate sources of prey or hosts, complimentary nutrients such as pollen and nectar, overwintering sites, etc. Simple monoculture farms rarely meet all of these needs over a sufficient period to insure adequate beneficial populations. By growing a carefully chosen set of insectary plants in and around the field, we provide the resources beneficials need to stand guard over the crop.

STRATEGY: Conduct a farm field day to attract interested farmers in the area. Advertise the opportunity to be a cooperator on our new project. Explain the habitat concept, provide information that helps farmers choose habitat plants. Allow farmers to observe the habitat and its effects on a working farm.

OUTCOME: A field day on December 16, 1996, at Naturfarm in Lompoc was attended by 45 people including some local leaders in the agriculture community. Dr Joseph Patt of Rutgers University discussed floral morphology emphasizing its roll in fostering beneficial insects. Nurseryman Jeff Chandler of Cornflower Farms provided growers with information about particular plant species that may be incorporated into habitat areas. Cindy Douglas and Deke led a tour of the farm describing the proper management of pest-break strips to optimize biological control. One cooperator was recruited.

Fighting New Pests of Avocados Biologically

PROBLEM: Persea mite and avocado thrips have become widespread in Ventura county. Studies by UC Cooperative Extension indicate that no registered pesticide controls the new pests.

SIGNIFICANCE: Avocado is among the most frequently planted trees among homeowners in our area. Many backyard avocado growers, ignorant of UCCE findings and of biological control, are watching their trees defoliate and attempting, in vain, to combat these pests with toxic materials.

STRATEGY: Conduct a biological control presentation for the general public explaining biological control in avocados and printed educational materials.

OUTCOME: The seminar, funded by UC SAREP, was conducted on August 23, 1997. Of the 120 participants, many brought leaves that we looked at under a microscope with a video screen. The varied mite and insect activity on the leaves led to discussion about what each person has done to care for his or her trees. We related efforts to increase mulching and floral diversity around their trees with evidence of biological control of pests.

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