Grant Information
| Knowledge Area | Subject of Investigation | Field of Science | Percent |
|---|---|---|---|
| 211 - Insects, Mites, and Other Arthropods Affecting Plants | 999 - Citrus, general/other | 1130 - Entomology and acarology | 100% |
While certain exotic pests and pathogens, such as citrus root weevil species (example: Diaprepes abbreviatus (L.)), citrus leafminer, Pyllocnistis cytrella Stainton, and citrus bacterial canker, Xanthomonas axonopodis (Hasse), have proven challenging to manage in Florida citrus and required unusual efforts of chemical input or tree removal as compared with most other pests and diseases in citrus, the arrival of the Asian citrus psyllid, Diaphorina citri Kuwayama, in Florida in the 1990s and the associated identification of a tree-killing disease, Huanglongbing (HLB), in Florida in 2005 (Grafton-Cardwell et al. 2013) essentially eliminated several decades of effort to develop effective IPM practices in Florida citrus. The disease is caused by a bacterial pathogen that this psyllid vector transmits. The pathosystem transformed Florida citriculture due to the severity of this disease with respect to tree decline and possible tree death. The associated need for intensive vector management to maintain existence of productive trees has resulted in a near elimination of previously effective biological control in Florida citrus (Grafton-Cardwell et al. 2013). Citrus growers in Florida are finding it increasingly difficult to maintain low HLB incidence in their plantings and to remain profitable, even as they implement inoculum removal via infected tree removal, multiple insecticide application strategies believed to be effective in keeping disease rates low, and enhanced nutritional programs which aim to reduce the impact of disease symptoms. The importance of effective vector control has risen as many growers are abandoning the strategy of inoculum removal and instead attempting to prolong life and productivity of diseased trees with intense supplemental applications of micronutrients. These strategies are costly; moreover, with eroding success in controlling HLB incidence possibly due to high surrounding inoculum pressure, it is becoming increasingly difficult to accomplish effective control. The loss of an insecticide due to development of resistance may be a future further blow to an industry that relies on insecticides for D. citri control and management of other significant pests. Long-term HLB solutions such as resistant citrus cultivars and other methods of blocking HLB transmission by the vector may succeed in the future, but they will take time, perhaps decades, to develop. Diaphorina citri transmits three species of bacteria belonging to the genus Candidatus Liberibacter. Ca. Liberibacter asiaticus is the most likely causal agent of the citrus HLB disease in the US, although Koch's postulates have not yet been fulfilled (Tylor et al. 2009; Pelz-Stelinski et al. 2010). First discovered in Florida in 1998 (Halbert 1998), D. citri quickly became established throughout the state, making its eradication impossible. Currently, D. citri can be found in all citrus growing US states; i.e. Alabama, Arizona, California, Florida, Georgia, Louisiana, Mississippi, South Carolina, Texas, as well as Hawaii (Grafton-Cardwell et al. 2013). In 2005, plants with HLB infection were detected in Florida; within 4 years, all 32 citrus growing counties in the state had HLB-infected citrus (Grafton-Cardwell et al. 2013). HLB is considered the most destructive disease of citrus crops in the world. All known citrus cultivars are susceptible to HLB (Folimonova et al. 2009), and prevention of disease transmission has proven difficult worldwide (Grafton-Cardwell et al. 2013). Infected young trees can die before they reach the fruit bearing stage (Grafton-Cardwell et al. 2013). Infected mature trees decline and can die within 5-10 years of infection, if not managed with enhanced nutrition. Before their demise, infected mature trees produce a portion of fruit that are unmarketable; these fruit are small, misshapen, with uneven Given the mobility of D. citri, HLB has rapidly spread in Florida despite efforts to control the disease (Boina et al. 2009a; Tiwari et al. 2010). D. citri adults disperse long distances during periods of peak activity and move the causal pathogen of HLB widely; particularly from unmanaged, abandoned areas into well managed groves (Tiwari et al. 2010). Grower neighbors often made independent decisions on production and pest management, and these tendencies are being overcome through outreach and demonstrations of the benefits of cooperative actions. A spray program effectively applied to a single block of citrus and not to neighboring blocks will be ineffectual, as untreated blocks serve as sources of infected D. citri and disease (Tiwari et al. 2010). Thus, it has become clear that area-wide, cooperative management of the vector has been necessary. Recently, the US National Academy of Science published a strategic plan for management of HLB and identified development and implementation of area-wide, cooperative so-called "Citrus Health Management Areas (CHMAs)" as the most important organizational priority for HLB management (National Research Council 2010). Significant progress has been made to develop these CHMAs and many already exist (www.flchma.org) (Rogers et al. 2012). Existing CHMAs will continue to improve in Florida and throughout the US in effectiveness and new ones will become established as new D. citri management strategies are developed. While D. citri is the main focus of this project, based on what is described above, other insect pests of Florida citrus (and other crops) will also be investigated to develop management strategies for multiple pests.
Resistance management of ACP: Insecticides are a fundamental component of our current strategy to control huanglongbing (HLB). Vector control is carried out with the goal of maintaining Asian citrus psyllid (ACP) population densities as low as possible. There is no threshold for a vector of a disease that can kill trees and render fruit unsuitable for consumption. Consequently, intense use of insecticides is necessarily practiced; however, such use can encourage development of insecticide resistance in ACP populations. Insecticide resistance is already developing in regional ACP populations in Florida (documented in our previous work), which could render our primary defense tools against citrus HLB ineffective or reduce their effectiveness. We have found that 100-fold resistance to imidacloprid can develop within only five breeding generations of ACP. We have also found that this can occur in the field and may cause reduced efficacy of this important tool for young tree protection. We have also uncovered the underlying physiological mechanisms for this resistance and uncovered the genetic basis for it, leading to development of tools such as RNAi. At least two new insecticide modes of action will be introduced to Florida ACP management soon. This project will continue monitoring for insecticide resistance and to develop an understanding for how to abate or delay the onset of resistance in ACP to existing and newly available tools as has been published by orevious protocols from out lab (Tiwari et al. 2011a,b; 2012). Recommendations for effective resistance management in the field will be guided by detailed laboratory investigations, making our practical efforts in the field highly efficient. We will determine how quickly resistance develops in ACP and how long it takes for it to reverse. We will investigate the potential for cross-resistance between a wide variety of insecticides in order to develop the most appropriate rotation protocols. We will also determine the fitness costs of resistance and how they affect psyllid biology; namely, development, reproductive potential, and pathogen transmission parameters. Finally, we will investigate the genetics and modes of inheritance of resistance to obtain a deeper understanding for how rapidly this can occur and the potential for keeping it at bay and/or reserving the problem once it appears. Collectively, outcomes from our experiments will result in practical strategies to maintain the effective use of current insecticides for ACP management. Recommendations from our studies will be incorporated into citrus pest management guides and delivered to growers through presentations and publications. Psyllid biology and management: Factors that affect host acceptance by Asian citrus psyllids (ACP) govern the transmission of huanglongbing (HLB) in citrus groves in Florida. These factors may be biotic or abiotic: size of tree, flushing status, nutritional status, disease infection status, volatile emissions, border effects, sun exposure or other microclimate variability. These factors can make some trees ('party trees') more attractive than surrounding trees resulting in overcrowded conditions that are optimal for transmission and acquisition of the HLB pathogen. Investigating the factors that render a tree more attractive may provide useful information for targeted management of the vector and the pathogen. Our goals are to determine the factors that govern host acceptance by ACP in citrus groves. Specifically, we will examine the biotic and abiotic parameters that differ between reset, mature, and 'party trees' (those inundated with ACP infestation) and how these factors affect host acceptance and ACP fitness. We will determine if resets and/or 'party trees' serve as sources of ACP populations in subsequent years and how dispersal to or from these trees may affect transmission of the HLB pathogen between local trees. Furthermore, the effect of time since acquisition of the HLB pathogen on host acceptance behavior will be examined. We expect that understanding these factors affecting psyllid host acceptance, performance, and distribution will provide useful information for psyllid management to restrict spread of HLB. Laboratory and field investigations will be based, in part, on previously established specific methods that our lab conducts routinely (Boina 2009a, Mann et al. 2011, 2012, 2013; Tiwari et al. 2010, 2011 a,b, 2012). We will also investigate the effect of non-neurotoxic and standard insecticides on ACP as described in Boina (2009b) and Tiwari et al. (2012b), as well as possible psyllid repellents as described in Mann et al. (2012b). All of the cited works our methods developed by and routinely used in our lab. Management of citrus leafminer by mating disruption: We are continuing our work on development of citrus leafminer mating disruption as an alternative tool to pesticides for citrus leafminer management. We are continuing evaluation of new formulations, deployment strategies, and applicators as described in Lapointe and Stelinski (2011) and Lapointe et al. (2011). Ambrosia beetle management: The redbay ambrosia beetle, Xyleborus glabratus, is an invasive beetle that has become established in the southeastern United States and transmits a fungus, Raffaelea lauricola, that causes lethal laurel wilt. Among the susceptible Lauraceae hosts are redbay, Persea borbonia and avocado, Persea americana. Given that X. glabratus transmits the pathogen causing lethal laurel wilt disease, there is a crucial need for detection of this pest at low population densities. Consequently, our goal is to create a better lure for monitoring and control of the redbay ambrosia beetle. We will analyze the volatile emissions of R. lauricola and test a synthetic fungus odor blend as a potential attractant in a natural redbay forest infested with X. glabratus. In initial trials, the synthetic Raffaelea odor blend was not attractive to the beetles by itself; however, traps baited with the Raffaelea odor paired with manuka oil lures captured 56% more beetles on average than manuka lures alone. In addition, we will develop Raffaelea lure prototypes with various release rates with a commercial partner to develop commercial products. Tri-tropic interactions plant-herbivore-predator (parasite) interactions: We hypothesize that (1) the age of the HLB infection may influence ACP host acceptance behavior, (2) nutritional supplementation of plants may increase attractiveness of citrus in decline from HLB, and (3) exposure to high levels of methyl salicylate will interfere with the ability of ACP to discriminate between infected and healthy plants. We will conduct olfactometer, semi-field, and field experiments to determine whether MeSA could be used as a tool to disrupt ACP host finding behavior and as a tool to attract its wasp parasitoids. Methods will be based on previously established lad protocols as cited in the Literature Cited section. We will also continue to develop plant-root defense chemicals into practical tools for enhanced biological control of root pests, such as Diaprepes root weevil in citrus as described in Ali et al. (2012).
Target Audience
Growers and professionals is the citrus, avocado, and other relevant specialty crop industries in Florida.
Changes / Problems
Nothing Reported
Training & Professional Development
I am advising one PhD student, Benita Shreshtha, who is working on interactions of Asian citrus psyllid natural enemies. Benita received the President's Prize from ESA for second place in the poster competition in Vancouver. In 2018, Denis Willett who graduated his PhD program from my lab was appointed as new Assistant Professor of Chemical Ecology at Cornell. In 2018, my student Nicholas Johnston graduated and began his PhD program under Xavier Martini. Also, students for whom I served as committee member, Eliot Smith (Entomology and Nematology), and Lindsy Iglesias, graduated. I am also serving on the committees of Alexandros Dritsoulas (Nematology-Gainesville/CREC) and Emilie Demard (Entomology-IRREC). I completed my mentorship of an international visiting scholar (Dr. Meeja Seo) who returned to Chungnam National University in the Republic of Korea. Dr. Seo worked on the ecology and management of ambrosia beetle species affecting forestry and avocado in Florida while working in my laboratory. She published several papers from her work in my lab. Also, I began mentoring one international PhD student (Wenquan Qin) from South China Agricultural University. Mr. Qin will be learning various techniques in insect toxicology while in my lab for a three month period. Currently, I am advising three post-docs in my lab. These three post-docs each specialize in projects dealing with insect toxicology, chemical ecology, and molecular insect-pathogen interactions, respectively. I also supervise two full time biological scientists and five short-term (OPS) techs in my program.
Dissemination Streams
My extension program focuses on development and delivery of statewide educational efforts in citrus pest management with the focus on optimizing the profitability and sustainability of citrus production with the following goals: 1) Changing grower behavior to maintain integrated pest management tactics in citrus under conditions of chronic disease(s) reducing yield and 2) Changing grower behavior to overcome insecticide resistance development. The goals and accomplishments of my extension program are described in depth in the abbreviated T&P packet below. In 2018, I delivered presentations at the UF IFAS Citrus Nursery Workshop, Citrus Growers' Workshop, Citrus Expo, Citrus Pest Management In Service Training # 31517, and Citrus Growers' Institute reaching approximately 1,200 people.
Next Reporting Steps
My 2019 research program will focus on meeting the goals of recently funded CRDF grants, as well as, existing USDA-MAC, USDA_SCRI and USDA-SCRI-CDRE funding obtained prior to 2018. My intention is to also continue to garner new funding for the lab. Specific areas of current research: Insecticide resistance management for key pests of citrus. Elucidation of mechanisms and implementation of appropriate management programs in the field. Investigation of the fundamental principles of vector-pathogen interactions with a focus on transmission mechanisms and effects of pathogen infection on vector host selection behavior. Development of a Bt-based management strategy for Asian citrus psyllid. Behavior, ecology, and management of ambrosia beetles (and their associated fungal communities) in avocado and forestry with a focus on the Laurel wilt pathosystem. Development and implementation of pesticide alternatives--attract-and-kill technologies--with focus on (but not exclusive to) Asian citrus psyllid. Identification of natural product chemicals that affect behavior of entomopathogenic and plant parasitic nematodes. Implementation of identified synthetic chemicals to modify nematode behavior in agroecosystems. Use of attractants for entomopathogenic nematodes to enhance efficacy of biological control. Use of nematode dispersal pheromones to repel plant pathogenic nematodes away from crops. Identification and implementation of insect repellents and attractants with a focus on Asian citrus psyllid, Diaprepes root weevil, Sri Lanka weevil, redbay ambrosia beetle, and moths. Development of management strategies for Asian citrus psyllid based on understanding of its general ecology. Evaluation of newly available agrochemicals (insecticides, adjuvants) for insect pest management in citrus.
Target Audience
Citrus growers and producers
Changes / Problems
Nothing Reported
Training & Professional Development
Although new area-wide ACP control programs were initially adopted in Florida in coordinated scale and incorporated resistance management strategies, their adoption was short-lived (2-3 years) and is now in question as growers struggle to maintain profits in the face of declining yields due to citrus greening. My continued monitoring of insecticide resistance revealed a recurrent problem with ACP resistant populations in 2017-present, which has been associated with product failures. The challenge of my current program is to develop and implement new methods for improved insecticide resistance despite lack of area-wide grower cooperation in some regions, reliance in less expensive insecticide chemistries, and greater disparity in practices between growers who manage their groves versus those who choose to drastically reduce or abandon management.
Dissemination Streams
I integrate a diversity of methods to meet the objectives of this extension program. In addition to formal or informal presentations and publications, a large portion of my research is conducted 'on-farm' in cooperation with grower collaborators. In this manner, I maintain direct contact with numerous citrus growers, allowing me to learn about their needs, their successes and new insights. It also allows growers to see the results of my research first-hand as it is taking place. In some cases, growers are able to see new or experimental technologies and methods long before they are implemented commercially. I have visited with over 45 citrus growers to discuss their individual citrus pest management problems and how to implement solutions. I regularly provide education by fielding phone calls and readily welcome walk-in visits to discuss citrus pest management needs of growers. I have disseminated new information about citrus pest management using UF's Electronic Delivery Source (EDIS) system. This includes information on citrus pest management practices, citrus production practices, and the biology and identification of pests in Florida citrus, as well as other agricultural crops. In addition to using EDIS, I have consistently provided up-to-date information to clientele and county faculty through publications in popular citrus industry magazines. I was the research manager of the Mid-Florida Citrus Foundation groves at Conserv II during 2011-2016. This was a non-profit foundation and grove operation located in Lake and Orange Counties that is administered by citrus growers in the central Florida region. This grove served as a resource for citrus research for approximately two decades prior to closing in 2016 due to decline from HLB. As research manager, I met with the grower board of directors and citrus agents, multiple times annually. During these meetings, we not only discussed grove operations and maintenance, but also identified pressing research needs for this site. As research manager, I served as liaison to other researchers and helped facilitate completion of their projects at the site. Field days were held at the site, during which hundreds of growers visit and see the results of research taking place in real time. This site served as a valuable resource for many of my own field experiments. This role at Mid-Florida Citrus Foundation allowed me to seamlessly integrate my research into my extension program. I have co-developed a web page on use of low volume application technology for management of Asian citrus psyllid. I also oversee a website dedicated to disseminating new information on Caribbean fruit fly management in citrus. I co-maintain the website Science for Citrus Health (http://ucanr.edu/sites/scienceforcitrushealth/). I also regularly develop new extension articles for this website. This website serves a teaching tool to educate growers on the research and methods being conducted and developed to protect citrus from the causative agent of citrus greening. With respect to presenting information on insecticide alternative tools for citrus pest management and insecticide resistance in Florida, I am one of the leading entomologists to deliver presentations at grower seminars, workshops, and field days on these topics. I regularly disseminate new information by way of presenting PowerPoint presentations (lecture-style grower conferences and workshops), poster presentations with handouts (field days), and brief written reports (evening small group grower meetings).
Next Reporting Steps
Nothing Reported
<br><br>
<br>What was accomplished under these goals? I have developed a program for evaluating new tools (experimental or currently unregistered pesticides) for management of key citrus pests and extend this information to growers and the pesticide industry in an efficient manner. I have focused a significant amount of my efforts on Asian citrus psyllid and citrus leafminer given the current needs of the industry, but have also actively pursued extension activities on other important pests, such as the Diaprepes root weevil. A large part of this program has been dedicated to educating growers on the use of low volume pesticide applications for control of Asian citrus psyllid. My extension and research programs have been intimately linked to produce measurable outcomes for improved citrus production. They have significantly contributed to the adoption and wide use of low volume pesticide spray technologies for management of Asian citrus psyllid in Florida. Low volume pesticide sprayers deliver 2-10 gallons of spray volume per acre and are thus able to cover many more acres of crop per hour, at a lower cost, than conventional pesticide sprayers. As a direct impact, my research and closely associated extension efforts significantly contributed to the issuing of four 24(c) (special local needs) labels to allow use of these products (Danitol, Mustang, Delegate, and Micromite) for Asian citrus psyllid management with low volume sprayers in Florida citrus. Following this progress in Florida, other researchers and extension personnel in Texas have educated citrus growers in that state regarding this technology for management of Asian citrus psyllid. Adoption of low volume technology in Texas for psyllid control is thus also beginning. Since this new use pattern of low volume application has become established for Asian citrus psyllid management in Florida, a significant portion of my extension program has continued to focus on educating growers on how to implement low volume spray technologies optimally, safely, and according to the law. Much of this extension effort has been based on the research findings of my laboratory and the laboratories of Drs. M. Salyani and M. Rogers from UF-CREC and Dr. P. Stansly from the UF- SWFREC. Partially based on my efforts, this technology is now widely adopted among the Florida citrus industry. Low volume application technology requires 30% of the investment of conventional airblast spraying for ACP control. As a direct impact, it has been estimated by economists focusing on citrus production that adoption of low volume ground technology as a component of Asian citrus psyllid management (beginning ca. 2009) by Florida citrus growers is saving the industry at least $40 million per year. My Extension program on the biology of key citrus pests has also contributed to statewide change in behavior regarding the problem of abandoned citrus groves in Florida. Currently, there are nearly 140,000 acres of abandoned citrus in Florida. My research program has clearly demonstrated that these abandoned groves have a negative impact on commercial citrus production by contributing to the introduction of pests and disease into adjacent managed areas. The integration of my research and Extension programs has led to changes in behavior including removal of these unmanaged, abandoned areas or site-specific management, such as a focus on border rows, for those growers who are adjacent to these problem areas. Another direct impact of this extension effort is its contribution to the addition of several new recommendations for pest management to the Florida Citrus Pest Management Guide (use patterns for Delegate WG, Movento 240 SC, Mustang Max, Sevin XLR, and Intrepid 2F). Also, a direct result of my effort has been a 24(c) (special local needs) label for use of Intrepid 2F insecticide against citrus leafminer in Florida citrus. The remaining portion of my effort in this program focuses on continued education of growers on optimal citrus pest management based on the recommendations set forth by the citrus Extension team in the Florida Citrus Pest Management Guide. My research efforts in this area have directly resulted in the registration of a pheromone-based mating disruption product (SPLAT-CLM) manufactured and distributed by ISCA Technologies for control of citrus leafminer in Florida citrus. This is a pesticide alternative control tool that protects crops by mating disruption (preventing reproduction) rather than deploying a toxicant. The 24(c) (special local needs) label was approved in April of 2010 with the assistance of my extension and research efforts on this topic. The product currently is fully labeled for use in Florida. My extensive statewide Extension program regarding the proper use of mating disruption for citrus leafminer has resulted in use of this technology on up to 3,000 acres of citrus in FL annually. To my knowledge, this is the first pesticide alternative pest control product to be developed, registered, and in the early stages of adoption for control of citrus leafminer in Florida and elsewhere. As adoption of this pest-specific and otherwise harmless (to the environment and non-target organisms) product increases, the negative impact of conventional pesticides (environmental contamination, killing of beneficial insects, pesticide resistance) should be reduced. Furthermore, my efforts in this program have increased the use of pheromone traps for citrus leafminer monitoring by Florida citrus growers. Grower adoption of pest monitoring should improve efficiency of pest management by allowing growers to better evaluate and time their annual treatments. <br><br><b>Publications</b><br>
Target Audience
The main target audienceincludes citrusgrowers, citrus nurseries, the agrochemicalindustry, and homeowners.
Changes / Problems
Nothing Reported
Training & Professional Development
My extension program continues to focus on development of educational tools and dissemination of information about: 1) insecticide resistance management for Asian citrus psyllid in Florida, and 2) arthropod and nematode management and monitoring technologies in citrus, and 3) insecticide alternative control strategies, such as mating disruption. I also assist the core extension management team regularly. I have also become involved in statewide extension programs dealing with ambrosia beetles in a small role.
Dissemination Streams
In 2017, I co-launched an educational website on citrus biotechnology and disease management with Peggy Lemaux (UC-Berkley) and Beth Grafton-Cardwell (UC-Riverside). This included introducing the grower and research community to this tool with presentations at the International Research Conference on HLB in Orlando, FL and the California Citrus Conference in Visalia, CA. By the numbers, in 2017, I presented or co-authored 10 extension talks and/or display presentations to groups of growers, production managers, or industry personnel. Also, I authored one trade journal article in the California Citograph. Finally, I co-authored one revised EDIS document. I also engaged in many phone call consultations, office visits, and several field visits as part of my extension responsibility.
Next Reporting Steps
My 2018 research program will focus on meeting the goals of recently funded NIFA-USDA-SCRI grant, two USDA-APHIS-MAC grant, as well as, new CRDF funding obtained obtained in 2016-17. My intention is to also continue to garner new funding for the lab, as calls for proposals are announced. Specific areas of current research: Insecticide resistance management for key pests of citrus. Elucidation of mechanisms and implementation of appropriate management programs in the field. Investigation of the fundamental principles of vector-pathogen interactions with a focus on transmission mechanisms and effects of pathogen infection on vector host selection behavior. Development of a Bt-based management strategy for Asian citrus psyllid. Behavior, ecology, and management of ambrosia beetles (and their associated fungal communities) in avocado and forestry with a focus on the Laurel wilt pathosystem. Development and implementation of pesticide alternatives--attract-and-kill technologies--with focus on (but not exclusive to) Asian citrus psyllid. Identification of natural product chemicals that affect behavior of entomopathogenic and plant parasitic nematodes. Implementation of identified synthetic chemicals to modify nematode behavior in agroecosystems. Use of attractants for entomopathogenic nematodes to enhance efficacy of biological control. Use of nematode dispersal pheromones to repel plant pathogenic nematodes away from crops. Identification and implementation of insect repellents and attractants with a focus on Asian citrus psyllid, Diaprepes root weevil, Sri Lanka weevil, redbay ambrosia beetle, and moths. Development of management strategies for Asian citrus psyllid based on understanding of its general ecology. Testing and implementation of biopesticides and insect growth regulators for pest control in citrus and other crops. Evaluation of newly available agrochemicals (insecticides, adjuvants) for insect pest management in citrus. Post-doctoral scholar and graduate student advising I will be advising 3 post-docs and 2 graduate students during 2018. I will also serve on committees of 3 other graduate students. Research Publications for 2018. I plan on publishing approximately 7-10 (possibly more) peer reviewed journal articles in 2018 in top-notch scientific journals. Extension program I expect that my extension role in the Florida citrus industry will continue at its current pace in both materials produced and impact. I will continue to work with all of the county extension agents focusing on citrus and continue educating growers about my research and the research of my colleagues at CREC, IFAS, and other institutions. I expect that I may be invited to contribute presentations at annual venues, as well, as the more intimate OJ breaks and small meetings. I will continue serving as one of the go-to people regarding psyllid resistance management, psyllid biology/ecology, as well as pyllid control with pesticide alternatives. I will also continue to be one of the go-to entomologists regarding other current insect pests such as the citrus leafminer and Diaprepes root weevil. I have developed a well-known extension role as educator of integrated management strategies, insect ecology, and pesticide alternatives. I will continue to distribute new information through publication in appropriate extension outlets such as trade journals or EDIS. Teaching Activities: Graduate student (1 Ph.D and 1 masters as advisor) and post-doc (3) advising will comprise the majority of my teaching activities, as well as, serving on other student committees (3 students). I will be co-instructing in the citrus pest management course at Lake Alfred in 2018, if it is offered and expect to guest lecture in multiple courses. <br><br>
<br>What was accomplished under these goals? Project Objectives: 1 Findings: The results indicate susceptibility reductions of ACP to a number of insecticides have returned to the levels where they were in 2010. As a reminder, we started to see decreased susceptibility to insecticides in 2009, which kept getting worse through 2013. In 2014, we saw a surprising, yet welcome reversal of the problem, which remained in 2015. We were never able to adequately explain why, but maybe CHMAs were helping. In 2016, there was evidence of reduced susceptibility again; however, this was not widespread. In 2017, we have further evidnce of decreased susceptibility levels among psyllid populations, particularly for neonicotinoid insecticides. For thiamethoxam, we are killing less than 30% of field psyllids at a concentration that should kill all of them. At that same dosage of imidacloprid, we are killing 40% of field psyllids when we should see 75% kill. Given the concentration of imidacloprid that was required to kill field psyllids and taking into account how much could be delivered to the leaf at a label rate dosage, it is possible that label rate efficacy may be reduced. Although the data indicate a mild shift for reduced sensitivity with the organophosphates and pyrethroids, that seems insufficient for product failure at this point. Insecticide resistance.After five applications, we measured the LC50values for four different insecticides and compared them with the laboratory population and the same field population before applications were made. Only insects in plots treated with dimethoate without rotation showed moderate levels of resistance to this chemical. Resistance was not recorded in any of the rotation treatments. Project Objectives: 2, 3, 5, 6, and 7 Findings: Dispersal of D. citri as Influenced by Temperature and Relative Humidity. Dispersal of D. citri increased linearly as temperature was increased within the range of temperatures tested and independently of relative humidity level. However, changes in relative humidity alone or humidity interacting with temperature had no significant effect on dispersal of D. citri. Removal of humidity, and of the humidity x temperature interaction improved the model as demonstrated by the lower AIC obtained for the simplified model. Similarly, the best GAM only included temperature as the predictor (estimate=0.0227, SE=0.002, P <br><b>Publications</b><br>
Target Audience
Florida citrus and avocado growers.
Changes / Problems
Nothing Reported
Training & Professional Development
I am co-advising one master's student, Nicholas Johnston. Also, I am advising one PhD student, Dara Stockton. In 2016, Denis Willett graduated his PhD program from my lab and he is currently a post-doc with the USDA in Gainesville. Also, Jeff Eikwort graduated with a Master's from my lab and he is currently working for the Florida Forest Service as a state forester. A master's student (Alicia Kelley) on who's committee I served also graduated in 2016. I am currently serving on the committees of 1) Alex Erp (Entomology and Nematology), 2) Lindsie Iglesias (Interdisciplinary Ecology), 3) Kevin Langdon (Entomology and Nematology), 4) Derrick Jent (Entomology and Nematology). and 5) Eliot Smith (Entomology and Nematology). Currently, I am advising two post-docs in my lab and co-advising another post-doc with the USDA. I also supervise two full time biological scientists and two short-term (OPS) techs in my program.
Dissemination Streams
My extension program continues to focus on development of educational tools and dissemination of information about: 1) Integrated pest management strategies for Florida citrus, and 2) Judicious use of pesticides including pesticide alternative tools, monitoring, resistance management, and pesticide application technologies, and 3) insecticide alternative control strategies, such as mating disruption. I also assist the core extension management team regularly. I have also become involved in statewide extension programs dealing with ambrosia beetles in a small role. The goals and accomplishments of my extension program are described in depth below. In 2016, I began co-developing an educational website on citrus biotechnology and disease management with Peggy Lemaux (UC-Berkley) and Beth Grafton-Cardwell (UC-Riverside). A beta version has been launched and we expect an initial useful version to launch in 2017. By the numbers, in 2016, I presented or co-authored 8 extension talks to groups of growers, production managers, or industry personnel. Also, I authored one trade journal article in Citrus Industry Magazine and a second in the California Citograph. Finally, I co-authored two revised EDIS documents. I also engaged in many phone call consultations, office visits, and several field visits as part of my extension responsibility. In 2016, I authored or co-authored 12 peer-reviewed articles in journals spanning several disciplines. My work published in 2016 was multidisciplinary and was published in respected journals. This includes papers in PLoS Computational Biology, Chemical Senses, BioControl, and Journal of Chemical Ecology among others. Several of my 2016 papers focused on management and biology of Asian citrus psyllid and ambrosia beetles. However, I also published papers on mating disruption and pheromone monitoring of moths; basic vector-pathogen interactions in the redbay ambrosia beetle-Laurel wilt pathosystem; and nematode chemical ecology and communication behavior. Some of my research publications in 2016 received significant media coverage and three were selected as issue covers. I authored one invited presentation and co-authored four presentations by my students and post-docs at the International Congress of Entomology. I processed and edited many papers as Associate Editor of Florida Entomologist, Environmental Entomology, and Frontiers in Ecology and Evolution. I reviewed many manuscripts in 2015 for several journals spanning many disciplines.
Next Reporting Steps
My 2017 research program will focus on meeting the goals of recently funded NIFA-USDA-SCRI grant; the USDA-APHIS-MAC grant, as well as, existing CRDF and USDA funding obtained prior to 2016. My intention is to also continue to garner new funding for the lab. Specific areas of current research: Insecticide resistance management for key pests of citrus. Elucidation of mechanisms and implementation of appropriate management programs in the field. Investigation of the fundamental principles of vector-pathogen interactions with a focus on transmission mechanisms and effects of pathogen infection on vector host selection behavior. Development of a Bt-based management strategy for Asian citrus psyllid. Behavior, ecology, and management of ambrosia beetles (and their associated fungal communities) in avocado and forestry with a focus on the Laurel wilt pathosystem. Development and implementation of pesticide alternatives--attract-and-kill technologies--with focus on (but not exclusive to) Asian citrus psyllid. Identification of natural product chemicals that affect behavior of entomopathogenic and plant parasitic nematodes. Implementation of identified synthetic chemicals to modify nematode behavior in agroecosystems. Use of attractants for entomopathogenic nematodes to enhance efficacy of biological control. Use of nematode dispersal pheromones to repel plant pathogenic nematodes away from crops. Identification and implementation of insect repellents and attractants with a focus on Asian citrus psyllid, Diaprepes root weevil, Sri Lanka weevil, redbay ambrosia beetle, and moths. Development of management strategies for Asian citrus psyllid based on understanding of its general ecology. Testing and implementation of biopesticides and insect growth regulators for pest control in citrus and other crops. Evaluation of newly available agrochemicals (insecticides, adjuvants) for insect pest management in citrus. Development of new insecticide delivery mechanisms including mechanical application devices and nano-technology release devices. Post-doctoral scholar and graduate student advising I will be advising 2 post-docs and 2 graduate students during 2017. I will also serve on committees of 5 other graduate students. I will also be co-advising a visiting PhD student from Iran in a collaboration with Dr. Larry Duncan's program. My intention is to begin recruiting a new PhD student as well. Research Publications for 2016. I plan on publishing approximately 13-16 (possibly more) peer reviewed journal articles in 2017 in top-notch scientific journals. Extension program I expect that my extension role in the Florida citrus industry will continue at its current pace in both materials produced and impact. I will continue to work with all of the county extension agents focusing on citrus and continue educating growers about my research and the research of my colleagues at CREC, IFAS, and other institutions. I expect that I may be invited to contribute presentations at annual venues, as well, as the more intimate OJ breaks and small meetings that take place regularly. Some of these have already been scheduled for 2016, such as the Florida Citrus Show in Fort Pierce. I will continue serving as one of the go-to people regarding psyllid management, psyllid biology/ecology, as well as pyllid control with pesticide alternatives. I will also continue to be one of the go-to entomologists regarding other current insect pests such as the citrus leafminer and Diaprepes root weevil. I have developed a well-known extension role as educator of integrated management strategies, insect ecology, and pesticide alternatives. I will continue to distribute new information through publication in appropriate extension outlets such as trade journals or EDIS. Teaching Activities: Graduate student (1 Ph.D and 1 masters as advisor) and post-doc (2) advising will comprise the majority of my teaching activities, as well as, serving on other student committees (5 students). I will likely contribute guest lectures to the Insect Physiology course on campus as I have done annually since 2006. I will also likely present a guest lecture in the Chemical Ecology seminar in Gainesville. I will be co-instructing in the citrus pest management course at Lake Alfred in the Spring of 2017. <br><br>
<br>What was accomplished under these goals? My research program in 2016 focused primarily on insect and pathogen interactions and pest management in citrus and avocado. My lab also conducted research on fundamental aspects of insect and nematode behavior and chemical ecology. Among some highlights from 2016, we found that a phytopathogenic fungus Raffaelea lauricola manipulates release of volatiles from its host to increase the attraction of its vector the redbay ambrosia beetle Xyleborus glabratus. Contrary to systems where a phytopathogen changes the odor of a host by increasing attractive volatiles to its vector, we found that R. lauricola is instead able to shut down the emission of a repellent, methyl salicylate, that follow fungus infection. The release of methyl salicylate is indeed correlated to the activation of the salicylic acid defense pathway and repels the arrival of the redbay ambrosia beetles. Importantly, R. lauricola and X. glabratus are responsible of a devastating disease in southeastern forest in North America, and have decimated the Lauracea population in this area. Our research led to the development of a push-pull management technique, which will be evaluated on large scale in avacado 2017; there is industry interest in pursuing this as a commercial product. We have also continued our fundamental and applied research on Asian citrus psyllid. Among some highlights for 2016, we found that drought stress affects citrus signaling, and particularly herbivore and pathogen induced volatiles. We found that the initial attraction of Diaphorina citri, the vector of the pathogen responsive of the citrus greening disease, was much lower under drought stress. Interestingly attraction of the vector to infected and non-stressed plants was correlated with greater release of methyl salicylate as compared with uninfected and non-stressed control citrus plants. Drought stress abolished methyl salicylate release from citrus greening plants as compared with non-stressed and infected plants. Conincidentally, we found that the parasitoid wasp, Tamarixia radiata, was attracted to headspace volatiles released from D. citri-infested citrus plants under control conditions. However, wasps did not show preference between headspace volatiles of psyllid-infested and uninfested plants, under drought conditions, suggesting that herbivore-induced defenses did not activate to recruit this natural enemy under drought stress. We have also investigated how abiotic factors, including temperature, humidity and barometric pressure influence Asian citrus psyllid dispersal and flight initiation. We found that Asian citrus psyllid dispersal increased with temperature but not with humidity. We also demonstrated that rapid fall of barometric pressure inhibited psyllid movement. Therefore, we believe that a better that these new data may help to predict psyllid arrival depending of abiotic factors. We have also spent considerable effort investigating the mating system of Asian citrus psyllid. We have found considerable behavioral plasticity in the reproductive repertoire of the Asian citrus psyllid. Most importantly, we uncovered the role male color polyphenisms play in directing female mate selection and fecundity. Combined, these results suggest that females use male appearance as an age-dependent sexual advertisement to maximize reproductive output. We have also found that female psyllids exhibit a strong capacity for learning with respect to choosing best hosts for ovipisition to maximize their fitness. We continue our work on resistance management of Asian citrus psyllid. We finished characterizing the sodium channel of this insect and understand a great deal about presentation of pyrethroid resistance; we developed a rapid and inexpensive technique to evaluate insecticide susceptibility of Asian citrus psyllid in the field on large scale; and we conducted our annual resistance survey of Asian citrus psyllid populations in Florida which indicated that we are doing a good job of managing the potential problem. Also, we have been conducting research on non-target effects of Asian citrus psyllid management on honeybees. Our work on the behavioral and chemical ecology of nematodes continues. Among some highlights, recently we have described the multitrophic effects of learning in these belowground parasitoids. In particular, we uncovered considerable social behavioral plasticity in entomopathogenic nematodes for their hosts, nematophagous fungal predators, and other entomopathogenic nematode parasitoids. Most importantly, we found and quantified the role social behavioral plasticity plays in amplifying belowground signals from plants. Combined, these results suggest a mechanism for regulation of community structure by plant signaling and highlight the role of behavioral plasticity in shaping community dynamics. <br><br><b>Publications</b><br>
Target Audience
Growers of produce; primarily citrus.
Changes / Problems
Nothing Reported
Training & Professional Development
Currently, I serve as chair of one M.S. student and chair of two Ph.D students in the Entomology and Nematology Dept. In addition, I serve on the committee of two M.S. students in the Entomology and Nematology Dept.; two PhD students in the Entomology and Nematology Department, and one student in the Doctor of Plant Medicine program.Training of graduate students and post-docs. I have two postdoctoral associates that I am mentoring. Also training of citrus and avocado growers, as well as, foresters. Also, participation in workshops and seminars.
Dissemination Streams
I presented or co-authored 3 extension talks to groups of growers, production managers, or industry personnel. Also, I authored two trade journal articles in Citrus Industry Magazine and a third one in the California Cytograph. Finally, I co-authored one revised EDIS document. I also engaged in many phone call consultations, office visits, and several field visits as part of my extension responsibility. I was also one of the lead co-organizers of the Grower Day that followed the 2015 IRCHLB meeting in Orlando and presented at this event at CREC.
Next Reporting Steps
I expect that my extension role in the Florida citrus industry will continue at its current pace in both materials produced and impact. I will continue to work with all of the county extension agents focusing on citrus and continue educating growers about my research and the research of my colleagues at CREC, IFAS, and other institutions. I expect that I may be invited to contribute presentations at annual venues, as well, as the more intimate OJ breaks and small meetings that take place regularly. Some of these have already been scheduled for 2016, such as the Florida Citrus Show in Fort Pierce. I will continue serving as one of the go-to people regarding psyllid management, psyllid biology/ecology, as well as pyllid control with pesticide alternatives. I will also continue to be one of the go-to entomologists regarding other current insect pests such as the citrus leafminer and Diaprepes root weevil. I have developed a well-known extension role as educator of integrated management strategies, insect ecology, and pesticide alternatives. I will continue to distribute new information through publication in appropriate extension outlets such as trade journals or EDIS. <br><br>
<br>What was accomplished under these goals? My research program in 2015 focused primarily on insect and pathogen pest management in citrus and avocado. My lab also conducted research on fundamental aspects of insect and nematode behavior and chemical ecology. In 2015, in collaboration with USDA-ARS, I made further progress on refinement and practical application of mating disruption for citrus leafminer. A new and commercially available product was again deployed by ISCA Technologies, in several Florida groves. We continued to evaluate its effectiveness in large-scale field tests. Approximately 3,000 acres of Florida citrus were treated with the product in 2015 and we have helped in evaluating the product with the help of CRDF funding. We have continued to make further progress on development of repellents and attractants for Asian citrus psyllid (ACP), as well as, other insect pests. My lab works with several companies that have plans to develop these lures into practical products (examples: Alpha Scents and ISCA technologies). In addition, in collaboration with scientists at UC Davis (Co-PI: Christina Davis), we developed a plant volatile-based attractant for both sexes of ACP. These results were published this year. Also, a patent application for this technology was filed. Furthermore, ISCA Technologies continues to work on commercializing an existing plant-based lure formulation for ACP and a significant amount of research on this product was conducted this year. Also, Alpha Scents has marketed a lure for ACP based on my research with M. Setamou and J. Patt. My lab also collaborated heavily with Scientists from MIT and University of Texas in 2015, developing a nano-technologies release device for insecticides. Were were able to develop a device that achieves that same efficacy against Asian citrus psyllid, yet uses 200 fold less active ingredient as compared with standard formulations of imidacloprid (published inGreen Chemistry). My lab also continues development of new lures for monitoring redbay ambrosia beetle. Two companies have expressed interest in developing this into a commercial product and much of that work was published this year. We also concluded a significant amount on research in 2015, published inThe ISME Journalon pathogen transmission in this vector complex, based on statewide collected data from Florida. With two newly funded USDA-NIFA-SCRI grants (see below), we will continue this research on the Laurel wilt problem over the next five years. A large portion of my lab's research is focused on Asian citrus psyllid and other pests of citrus. I have also become involved in research on the Myllocerus beetle; however, this was only initiated since we did not receive funding for this in 2015. One focus has continued to be elucidating the mechanisms of insecticide resistance in ACP, surveying resistance throughout the state, and working on developing appropriate resistance management protocols and tools for managing resistance. Other basic and applied research on ACP included investigations of overwintering sites in Florida and alternative hosts; psyllid dispersal behavior; induced plant resistance in citrus against ACP; and laboratory and field evaluations of various chemistries for possible management of ACP and other insects in Florida. We also continued CA Citrus Research Board research on ACP chemical ecology and attractants and made significant progress towards development of practical tools. Research was also conducted on: mating disruption of multiple pests in multiple crops; practical management of redbay ambrosia beetles; and ecology, behavior, and application of entomopathogenic nematodes. In additional to practical research geared toward pest management, the lab continues to conduct fundamental ecological research focused on insect learning and behavior. The two research thrusts are meant to complement one another. <br><br><b>Publications</b><br>
Target Audience
Citrus growers, small and tree fruit growers, intergrated pest management extension specialists, extension and outreach, formal course instruction.
Changes / Problems
Nothing Reported
Training & Professional Development
Training of graduate students and post-docs. Also training of citrus and avocado growers, as well as, foresters. Also, participation in workshops and seminars.
Dissemination Streams
Results have been dissminated though refereed publications and book chapters, industry grower magazine articles, extension presentations and workshops, professional seminars and meetings/presentations, online websites, and direct contact with clientelle.
Next Reporting Steps
Nothing Reported
<br><br>
<br>What was accomplished under these goals? My research program in 2013 focused primarily on citrus pest management, and fundamental aspects of insect and nematode behavior and chemical ecology. In 2013, in collaboration with USDA-ARS, I made further progress on refinement and practical application of mating disruption for citrus leafminer. A new commercially available product was launched by ISCA technologies, named DCEPT. We verified its effectiveness in large-scale field tests. Based on this work, a meeting was held between the CRDF board and ISCA technologies. A plan has been proposed to treat 3,000 acres of Florida citrus in 2014, based on this research. Funding would come from the CRDF, growers, and ISCA. The plan is under evaluation currently. This would be the first area-wide scale use of mating disruption for citrus leaminer. My lab has made further progress on development of repellents and attractants for Asian citrus psyllid. This has included the publication of female-specific cuticular hydrocarbons that are attractive to male ACP. Three companies (Alpha Scents and Bayer in the U.S.A. and Contech Inc in Canada) have expressed interest in developing this further into potential practical tools and some have initiated R&D. In addition, in collaboration with scientists at UC Davis (PI: Christina Davis), we have further refined and improved a plant volatile-based attractant for both sexes of ACP. A patent and associated manuscript for publication are both in the works currently from that collaboration. Furthermore, ISCA technologies is working on commercializing an existing plant-based lure formulation for ACP. My lab also developed and published a new lure for monitoring redbay ambrosia beetle. Two companies have expressed interest in developing this into a commercial product. A large portion of my lab’s research was focused on Asian citrus psyllid. This included further elucidating the mechanisms of insecticide resistance in ACP, surveying resistance throughout the state, and working on developing appropriate resistance management protocols and tools. Other basic and applied research on ACP included investigations of overwintering sites in Florida and alternative hosts; psyllid dispersal behavior; induced resistance in citrus against ACP; and laboratory and field evaluation of a novel chemistry (cyazipyr) that will be launched for ACP management in 2014. Research was also conducted on: mating disruption of multiple pests in multiple cropping systems; practical management of redbay ambrosia beetles; and ecology of entomopathogenic nematodes. <br><br><b>Publications</b><br>