- Author: Ben Faber
I recently went looking for our copies of Walter Ebeling's book on pests of subtropical tree crops. It was created over 40 years ago, but is still a great reference for past pests and those that still pop up with less frequency than avocado thrips and persea mite do today. But both copies have disappeared from the office. and we have a new entomology advisor - Hamutahl Cohen - who is coming up to speed on the pest issues of our coastal area.
But all is not lost. It's online. This is the section of Subtropical Fruit Pests by Walter Ebeling that covers avocado pests in not only California, but what was and is known to exist in other avocado growing regions around the US and the world. It was reproduced at the Hofshi Foundation's Avocadosource website. At this point it only contains the chapters pertaining to avocado. Other chapters in the full text cover citrus, grape, walnut, almond pecan, olive, fig, date and other "Minor Subtropical Fruits". The beauty of the book is not only historical, but that it is still current (although the DDT recommendations are out of date) for many pests. It also chronicles pests that have appeared in the past, disappeared and then reappeared. An example is Avocado Bud Mite - here, gone, here and seemingly gone again, probably to reappear sometime in the future. This is no replacement for the UC-IPM website, http://ipm.ucanr.edu/PMG/crops-agriculture.html , but it is a good look at how the pest has been managed in the past and is done so currently. http://www.avocadosource.com/papers/research_articles/ebelingwalter1959b.pdf
I thought I had the only copies of this book in Ventura County, but you could too. There are some listed on ABE Books for cheap, which is where I got our replacement. At one point the University of California made hard copies of all manner of valuable material available for cheap or free. It still does, but much is online now. Check out the selections: https://anrcatalog.ucanr.edu/
This pestiferous book was compiled by Walter Ebeling at UC Riverside/Los Angeles. He was of some note, considered the Father of Urban Entomology. As you can see from the descriptions of avocado pests, he was a good all round entomologist, as well. Urban entomology really forces you to know a lot because of the diversity of arthropods in urban settings. He passed in 2010 and was recognized world-wide for his work.
- Author: Ben Faber
DPR funds educational resources to increase the adoption of reduced-risk, sustainable pest management practices for farmersAs part of DPR's goal to accelerate the transition to safer, more sustainable pest management and fulfill its mission to foster reduced-risk pest management, DPR has funded a project with Wild Farm Alliance (WFA) to provide educational resources for farmers to encourage the use of beneficial birds for pest control. When beneficial birds are supported, they can sustainably reduce pest insects and rodents that cause crop damage. Wild Farm Alliance created two free Continuing Education Courses about supporting avian pest control. The courses are online and can be taken any time throughout the year. These courses are approved for CE credit through DPR. Habitat on Farms Support Avian Pest Control Services (4 CE Units) Participants will learn about research that shows the benefits of installing habitat in and around farms to attract beneficial birds that provide valuable pest control services. Nest Boxes and Perches on Farms Support Avian Pest Control Services (3 CE Units) Participants will learn about the research showing the benefits to the farm of installing Western Bluebird and other songbird nest boxes, Barn Owl and American Kestrel boxes, and songbird and raptor perches to gain these birds' valuable pest control services. DPR's Integrated Pest Management Branch is supporting the use of sustainable pest management strategies in our state in a variety of ways, including funding these educational courses on beneficial birds for Pest Control Advisors and pesticide applicator license and certificate holders. https://content.govdelivery.com/accounts/CADPR/bulletins/35b24c1
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- Author: Kathey Keatley Garvey
Sometimes distant relationships are better than close relationships.
https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=43912
Persimmons, asparagus, figs and other crops distantly related to native California plants attract fewer pests and diseases than the closer kin, and thus receive fewer pesticide treatments, according to a newly published article by two UC Davis-linked scientists in the Proceedings of the Natural Academy of Sciences (PNAS).
Co-authors Ian Pearse, research ecologist with the U.S. Geological Survey and a UC Davis alumnus, and Jay Rosenheim, UC Davis distinguished professor of entomology, analyzed the 2011-2015 state records of pesticide applications of 93 major California crops.
“We hypothesized that California crops that lack close relatives in the native flora will be attacked by fewer herbivores and pathogens and require less pesticide use,” said Rosenheim, a 32-year member of the UC Davis Department of Entomology and Nematology faculty and a newly elected fellow of the Entomological Society of America.
Rosenheim and Pearse examined the pesticide applications against arthropods, pathogens, and weed plants and compiled the data into a comprehensive analysis.
Their findings appear in the PNAS article, “Phylogenetic Escape from Pests Reduces Pesticides on Some Crop Plants,” published Oct. 12. “Phylogenetic relationship” refers to the relative times in the past that species shared common ancestors.
“It is well understood that many of the insect pests and diseases that attack our crops are often invasive species that come from overseas,” Rosenheim explained. “Almost all crops grown in California have been domesticated from wild plants whose area of origin is overseas, and many of the invading pests come from the original home of the wild ancestor of the now domesticated crop plant.”
“In contrast, our study focuses on the roughly half of all herbivores and diseases that attack California crops and that are actually native to California. These organisms originally attacked members of the native California flora, but have now shifted to attack a novel host: the crop plant.”
However, “host shifts aren't always easy,” Rosenheim said. “It's relatively easy to shift to attack a close relative of a native host plant, but it's relatively hard to shift to attack a very different host plant.”
Said Pearse: “Our study shows that crops like dates, asparagus, figs, kiwis, or persimmons that are distantly related to native California plants--and thus separated by many million years of independent evolution-- are colonized by fewer pests and diseases.”
These crop plants, the scientists said, are “too different” to be attacked readily. As a result, fewer pesticide applications are needed to protect those crops. “Thus, we can capitalize on an understanding of the evolutionary relatedness of crops and native plants to find crops that will suffer less attack, and that can therefore be grown with less use of toxic pesticides,” Pearse pointed out.
"The crops that require the most pesticide applications, Pearse said, "are those, like artichokes, blackberries, and sweet corn, that have close relatives in the Californian flora and are of high economic value per acre."
California's top agricultural crops include almonds, grapes, lettuce, strawberries, tomatoes and walnuts.
Rosenheim said persimmons are a good example “of the phenomenon we've studied: they have very, very few pests--almost zero in my experience--and that's probably because persimmons have no close relatives in the California native plant community.”
Pearse, a 2005 Fulbright scholar who received his doctorate in ecology from UC Davis in 2011, studying with Professor Rick Karban, joined the U.S. Geological Survey in Fort Collins in 2016. He focuses his research on invasive species and plant-insect interactions. Rosenheim researches insect ecology, with a focus on host-parasitoid, predator-prey, and plant-insect interactions, with direct applications to biological control.
“Pesticides are a ubiquitous (found everywhere) component of conventional crop production but come with considerable economic and ecological costs. We tested the hypothesis that variation in pesticide use among crop species is a function of crop economics and the phylogenetic relationship of a crop to native plants, because unrelated crops accrue fewer herbivores and pathogens. Comparative analyses of a dataset of 93 Californian crops showed that more valuable crops and crops with close relatives in the native plant flora received greater pesticide use, explaining roughly half of the variance in pesticide use among crops against pathogens and herbivores. Phylogenetic escape from arthropod and pathogen pests results in lower pesticides, suggesting that the introduced status of some crops can be leveraged to reduce pesticides.”
Coffee, anyone?
- Author: Ben Faber
What Are the UC Ag Experts Talking About?
Join the online crowd
February 19, 2020
Pesticide Resistance Management of Citrus Pests
Dr. Elizabeth Grafton-Cardwell will talk about how insects develop resistance (including examples of resistance in citrus thrips, California red scale, and citricola scale), pesticide use tactics to avoid resistance, the potential for resistance in Asian citrus psyllid, and best practices for citrus pest management. One hour of DPR continuing education unit is approved.
webinar registration at Pesticide Webinar
This presentation is part of the series of 1-hour webinars, designed for growers and Pest Control Advisers, highlighting various pest management and horticultural topics for citrus and avocados. During each session, a UC Expert on the subject will make a presentation and entertain write-in questions via chat during and/or after the presentation. As we develop this program, we may expand to other crops.
Upcoming topics:
- Gibbing in Avocados (Ben Faber, March 2020)
- Citricola scale by Elizabeth Grafton-Cardwell (April 2020)
- Invasive shot hole borers in avocado by Akif Eskalen (May 2020)
- Vertebrate pests by Roger Baldwin (June 2020)
- Ants in citrus by Mark Hoddle (July 2020)
- Use of plant growth regulators on citrus by Ashraf El-kereamy (August 2020)
- Author: Ben Faber
Biological control is the management of pests and their damage by the beneficial action of parasites (parasitoids), pathogens, and predators. These beneficial organisms, collectively, are named natural enemies.
Conserving (or protecting) and releasing natural enemies are important components of integrated pest management (IPM). In most situations, employing practices that conserve natural enemies is more effective, and less expensive and time consuming, than purchasing and releasing them.
Learn about the specific situations where purchasing and releasing parasites and predators can increase the effectiveness of biological control. Before purchasing natural enemies, consult the University of California (UC) IPM Pest Management Guidelines for that crop to learn whether UC research has shown that releasing them is effective. Some natural enemies on the market have never been demonstrated to effectively control any agricultural pest in California.
Obtaining Natural Enemies
Natural enemies can be purchased directly from various producers (companies that rear them) and suppliers (companies that purchase from producers and repackage and resell them). Some sources of parasites and predators are members of the Association of Natural Biocontrol Producers (ANBP). All ANBP members formally agree to a code of ethics and standardized methods.
Natural enemies purchased by users are commonly delivered via shipping services. Purchase parasites and predators only from in-state providers. It is illegal to obtain insects and other arthropods outside of California and carry or have them shipped across state lines without a permit from agricultural officials. Some pest control advisers and pest scouts will procure and release natural enemies as a service for growers.
Methods for Releasing Natural Enemies
Two methods for releasing natural enemies are inoculation and inundation:
- Inoculation—relatively few natural enemies are released. The offspring of these natural enemies provide biological control, not the individuals released.
- Inundation—large numbers of natural enemies are released, often several times over a growing season. The natural enemies released, and possibly their offspring, provide biological control.
The mealybug destroyer is an example of a natural enemy that is only released through inoculation—at relatively low numbers once per year early in the growing season. Aphytis melinus and Trichogramma parasites are released by inundation—at regular intervals over the growing season—to control California red scale and eggs of pest moths, respectively. Both inoculation and inundation can be used with predatory mites, depending on the situation.
Releasing Natural Enemies Effectively
Releasing natural enemies is most likely to be effective in situations where: 1) University of California researchers or other pest management experts have previously demonstrated success and 2) some level of pests and their damage can be tolerated in that crop. Desperate situations are not good opportunities for releasing natural enemies. Pests or their damage may already be too widespread for any release of parasites or predators to prevent economic loss of crop quality or quantity.
Increase the likelihood that natural enemy releases will be effective by
- Accurately identifying the pest and its natural enemies.
- Learning about the biology of the pest and its natural enemies.
- Releasing the appropriate natural enemy life stage and species.
- Releasing when the pests' vulnerable life stage(s) are present and at numbers that can be controlled by natural enemy releases.
Natural enemies are unlikely to be effective when released as if you were applying a pesticide. Instead, anticipate pest problems and begin making releases before pests are too abundant or economic damage is imminent.
- Remember that natural enemies are living organisms that require food, shelter, and water. Protect them from extreme conditions. For example, release them at night or early in the day during hot weather.
- Avoid applying broad-spectrum, residual (persistent) insecticides and miticides, and in some situations certain systemic or other pesticides, before or after releasing natural enemies. When needed, use pesticides selectively. For example, spot spray only where pests are abundant but localized.
Common reasons for the lack of satisfactory biological control after releases include the
- Application of broad-spectrum, residual insecticides, or in some situations systemic or other pesticides, prior to or after a release.
- Incorrect timing of release.
- Release of the wrong natural enemy for the pest situation.
- Release of a natural enemy species that is known to be ineffective.
For information on the use of biological control, see the UC IPM Pest Management Guidelines for your crop and specific pests. Most crops have a table called “Relative Toxicities of Insecticides and Miticides to Natural Enemies and Honey Bees” in the “General Information” section. Use these resources to guide pesticide selection to conserve natural enemies and improve biological pest control.
More Information
- Association of Natural Biocontrol Producers, Clovis, CA
- Grower Guide: Quality Assurance of Biocontrol Products (pdf), Vineland Research and Innovation Centre, Ontario
- Insectary Plants
- Natural Enemies Gallery
- Natural Enemies Handbook: The Illustrated Guide to Biological Pest Control
- Protecting Natural Enemies and Pollinators
- UC IPM Pest Management Guidelines
This Page is duplicated from the UC Integrated Pest Management website - https://www2.ipm.ucanr.edu/agriculture/natural-enemy-releases-for-biological-control-of-crop-pests/
Photo of predatory" mealybug destroyer" or Cryptolaemus