Grant Information
| Knowledge Area | Subject of Investigation | Field of Science | Percent |
|---|---|---|---|
| 216 - Integrated Pest Management Systems | 999 - Citrus, general/other | 1130 - Entomology and acarology | 40% |
| 216 - Integrated Pest Management Systems | 1099 - Tropical/subtropical fruit, general/other | 1130 - Entomology and acarology | 30% |
| 215 - Biological Control of Pests Affecting Plants | 999 - Citrus, general/other | 1130 - Entomology and acarology | 20% |
| 215 - Biological Control of Pests Affecting Plants | 1099 - Tropical/subtropical fruit, general/other | 1130 - Entomology and acarology | 10% |
Citrus production in California (oranges, grapefruit, lemons, and mandarins combined) had a 2010 crop value of $1.26 billion. Bearing citrus in the state is grown on a total of 268,600 acres within 5 diverse climatic regions - the Sacramento Valley, San Joaquin Valley, southern California coastal, southern California interior, and southern California desert regions. Arthropod pest management problems and solutions vary greatly between the various climatic regions and on different varieties of citrus within each region. Asian citrus psyllid (ACP) was first found in California late in 2008, has now spread throughout much of southern California, and is under "eradication" (really suppression) in much of southern California. In recent months, officials have come to the realization that the massive Los Angeles area infestation is beyond control and biological control is now being looked at to replace chemical treatment of backyard trees. Huanglongbing is a serious bacterial disease of citrus vectored by ACP and this disease has had severe impacts on citrus production in China, Brazil, Florida, and more recently, Mexico. The disease is moving northward towards California from Mexico and it is only a matter of time before the HLB is found in California and ACP spreads into the San Joaquin Valley production region. This project will address the need to make citrus arthropod pest control more reliable and less costly while minimizing the grower's reliance on broad-spectrum pesticide use to the degree that is possible. Substantial effort will be spent on helping the industry determine how to best deal with Asian citrus psyllid. This will logically progress from the current situation where we are mostly in suppression mode while the insect expands its range, then to a management phase once eradication/suppression is no longer feasible, and then to a third phase once huanglongbing is found and spreads in California. Based on 2010 statistics, avocados in California had an annual crop value of $415 million and were grown on 58,500 acres with the majority of this located in the coastal regions of San Diego, Ventura, and Santa Barbara counties. Prior to the early 1990's, California avocado growers were able to manage their arthropod pest problems with minimal chemical intervention and relied heavily on cultural and biological controls. This pattern was disturbed in recent years by the increasing importance of two newly introduced exotic pest species, the avocado thrips and persea mite. On citrus, research will focus largely on Asian citrus psyllid with continued research on citrus thrips; soft scales including black scale and citricola scales; bean thrips; Fuller rose beetle and Diaprepes root weevil; and mites or other contaminants of export citrus. On avocados, research will focus on avocado thrips and persea mite, focusing on basic biology, alternative management methods, selective chemical control, pesticide resistance management, and evaluation of the any promising natural enemies. Proactive research will be conducted on exotic armored scales that are likely to be introduced into California in the future and their biological control.
Develop, test, and implement improved pest management strategies for arthropod pests of citrus and avocados and their natural enemies in California. On citrus, research will focus largely on Asian citrus psyllid with continued research on citrus thrips; soft scales including black scale and citricola scales; bean thrips; Fuller rose beetle and Diaprepes root weevil; and mites or other contaminants of export citrus. On avocados, research will focus on avocado thrips and persea mite, focusing on basic biology, alternative management methods, selective chemical control, pesticide resistance management, and evaluation of the any promising natural enemies. Proactive research will be conducted on exotic armored scales that are likely to be introduced into California in the future and their biological control. On both commodities, research will be reactive to the current situation, i.e. a number of scenarios could alter the focus and emphasis placed on different research projects, e.g., (1) the appearance of Asian citrus psyllid in the San Joaquin Valley, (2) the emergence of huanglongbing on California citrus, (3) escalation in citrus thrips resistance to spinetoram or avocado thrips or persea mite resistance to abamectin, (4) the appearance of a new exotic pest on either commodity, or (5) citrus exports to a particular country face a new phytosanitary challenge. Specific high priority objectives over the 5 years of this revision are:
Based on an understanding of the biology of the pest species on citrus and avocado and interactions with other pest species and natural enemies, develop improved management strategies which will lead to minimization of economic damage while utilizing minimal economic and agricultural chemical inputs. A number of procedures will be used to achieve the objective for specific pest management problems including but not limited to the following. a. Literature review and development of pest management simulation models where appropriate. Models may aid in problem formulation or may be based on degree-day accumulations to assist in field monitoring programs. b. Laboratory and/or field-based studies on the basic biology of the pest and/or natural enemies of interest. c. Development of improved field monitoring methods and refinement of economic thresholds. d. Monitoring of pesticide resistance levels and determination of the mechanisms and genetics of resistance and/or cross-resistance. e. Pesticide efficacy evaluations. Develop selective control alternatives and evaluate new classes of chemistry. f. Evaluation and improvement of biological controls through monitoring and/or natural enemy or pesticide manipulations. Study the biology of endemic parasitoids and predators and determine if their impact can be augmented. Import new parasitoid species or strains through Quarantine and conduct field releases after obtaining permits for importation and release. g. Develop improved methods of rearing natural enemies in the laboratory and/or in insectaries. Do field evaluation of inoculative and/or augmentative natural enemy releases. In relation to the specific high priority objectives (1) - (3) listed above, the following initial procedures will be used: (1) Conduct laboratory and field spray efficacy trials to evaluate selective chemicals and/or new classes of chemistry. (2) A number of parasitoid species are in culture, some collected locally and others resulting from foreign exploration or from shipments by cooperators. Basic biology studies, host specificity research, and requests for release from Quarantine will be conducted as needed. Methods will be developed for rearing high quality host material and for efficient rearing of parasitoids so as to produce the numbers needed for field release. Inoculative or augmentative release programs will be developed and evaluated in various regions of California. (3) Pest management on citrus and avocado in California is evolving rapidly as new issues arise (more restrictive pesticide and environmental regulations, an increasingly global marketplace with stronger foreign competition, reduced restrictions on trade with lessened phytosanitary security, public pressure for improved food safety and product quality, urban interface issues, increasing land, labor, and water costs, etc.) and new pest species are introduced. These new issues and pest species must be integrated into applied pest management programs that allow citrus and avocado growers to compete in a challenging and competitive marketplace.
Target Audience
The target audience of these research efforts is largely citrus and avocado growers and pest control advisors in California, University of California farm advisors and specialists, and researchers working on citrus and avocados in California and other areas of the world. Much of the information and research is relevant to researchers, advisers, and growers in other areas of the world such as Arizona, Florida, and Texas in the U.S. and Australia, Brazil, Chile, Israel, Mexico, New Zealand, Peru, South Africa, and Spain.
Changes / Problems
As Asian citrus psyllid (ACP) and huanglongbing continued to expand in California, more emphasis was placed on dealing with this disease vector (ACP) at the expense of work on other citrus pests. In addition, research focused on citrus export problems due to contamination by quarantine pests including Fuller rose beetle, ASYNONYCHUS GODMANI (South Korea); bean thrips, CALIOTHRIPS FASCIATUS (Australia); and several mite species (New Zealand). Due to the sensitivities involved in international trade, substantial unpublished research was conducted on these quarantine pests. Two new avocado pests appeared late in 2015, the Kuroshio shot hole borer and later the polyphagous shot hole borer (both are EUWALLACEA nr. FORNICATUS). These insects vector several fungi, in particular two FUSARIUM fungi that cause Fusarium dieback. At the request of the California Avocado Commission, research was shifted from other pest species to emphasize work on these beetles.
Training & Professional Development
Over the 5 years of this project 36 presentations were made to growers, pest control advisors and others training them on how to best deal with Asian citrus psyllid, 17 with shot hole borers on avocados, 13 covering proactive pesticide resistance management, 11 dealing with managing Fuller rose beetle in relation to export shipments to South Korea, and 8 dealing with other citrus export issues. In addition, at the request of USDA-APHIS, 18 presentations were made to County Agricultural Commissioner inspectors training them on how to deal with citrus export issues relating to citrus shipments to South Korea, China, Australia, and New Zealand.
Dissemination Streams
Research results were reported as refereed scientific journal articles, which are abstracted and available on the worldwide web to other researchers, advisors, specialists, pest control advisors, and more and more to growers as they become increasingly computer literate; and also as technical reports in lay magazines written targeting growers and pest control advisors. Practical approaches and applications were reported at numerous meetings with the citrus and avocado industries over the year and via 3-4 annual reports that were required for all industry-funded grants. As new information was obtained, web-based pest management guidelines for citrus (http://ipm.ucanr.edu/PMG/selectnewpest.citrus.html) and avocado (http://ipm.ucanr.edu/PMG/selectnewpest.avocado.html) were updated and revised.
Next Reporting Steps
This project will be terminated as of June 2017 so there will not be another reporting period.