NE2001: Harnessing Chemical Ecology to Address Agricultural Pest and Pollinator Priorities
(Multistate Research Project)
NE2001: Harnessing Chemical Ecology to Address Agricultural Pest and Pollinator Priorities
Duration: 10/01/2020 to 09/30/2025
Statement of Issues and Justification
The need, as indicated by stakeholders:
Agriculture is both culturally important and an economic driver in the Northeast, and both culture and economics are driving us towards a strong need for more sustainable agroecosystems. For example, the total value of principal crops in the Northeast was > $5.32 billion and Northeast vegetable growers harvested over 133,000 acres with a value more than $700 million. New York alone ranked 5th in the nation for vegetable production and garnered $323 million from fruit, berry and grape production (NASS 2013). In addition, agriculture in the eastern United States is focused on many crops that require insect pollination. The combined value of these crops based on 2016 data from the USDA National Agricultural Statistics Service (http://www.nass.usda.gov/) is $10.49 billion/year. And pollination services in agriculture are worth about $500 million for the State of New York alone, highlighting the economic importance of both the crops and the beneficial insects that support them. Food security is of growing importance for the large segment of the population living in large cities which rely on imported food and also for the rural population, so maintaining agricultural productivity is essential for the well-being of many in the region.
Agriculture in the Northeast is valuable and productive, relying on a mix of growing practices that range from heavy reliance on pesticides to integrated pest management and adopting organic practices. To support this diverse base of food production, innovations are needed that reduce the risks of pesticides in conventional agriculture and enhance the productivity in organic systems. On behalf of stakeholders, the Northeast IPM Center states that they 'are enthusiastic about alternative, non-pesticidal strategies that unite several disciplines and lead to sustainable solutions'. They continue to say “the demand for organic fruit and vegetables continues to grow, and producers are demanding holistic, ecology-based systems”. Northeast regional priorities for fruit, vegetable and specialty crops are replete with calls for research and sustainable practices to reduce the impacts of insect pests and to protect valuable pollinators. This multi-state project seeks to harness innate properties of crops and agroecosystems to address pest and pollinator priorities. Although the project does not advance specific research questions restricted to particular crops, the broader umbrella allows for dynamic groups to form, meet annually, and address pressing questions in applied pest and pollinator management across the region.
The purpose of this multistate project is to provide a framework and opportunity for collaboration for diverse land grant researchers to work together to solve pressing problems in pest and pollinator management. The project aims to bring people together around a set of general goals. This broad umbrella allows us to coalesce a dynamic group of researchers from different locations and funding situations. The multistate project itself does not have funding for participants, which means that the project must be broad in order to bring in as many chemical ecologist participators as possible. Participants fall into three categories from which they may garner funding to participate in the project: 1) Researchers at a subset of Agricultural Stations that can apply for multistate funding to conduct a specific research project, 2) Researchers who can bring in external funding to conduct a project in support of the multistate project goals, and, 3) researchers who have no funding other than a small amount to cover the cost of travel to the annual multistate meeting. Even in New York, a State where researchers can receive funding through the multistate project, the individual researchers must apply for separate funding by submitting an individual proposal with a specific set of questions and methods that must be peer reviewed before funding is received.
Because of these funding differences among participants, we have purposefully written topical areas that are broadly important for advancing applied agricultural pest and pollinator management in the northeast and the US. This allows researchers to join dynamically and contribute in a way that works for them and their research partners. Some people simply use attendance at the annual meetings to share ideas, which have already been enormously beneficial and often leads to the development of funded projects down the road. Others use the multi-state project to launch an external grant, such as research grants and the USDA-NIFA equipment grants. This flexibility allows us to have broad participation, innovation, and shared goals, which has been key to allowing this group to encompass the top set of researchers it has attracted.
- Develop chemical ecology tools, information and deployment strategies to support sustainable agriculture by reducing damage by pests in crops and ornamentals, including potatoes, brassicas, cucurbits, apples, blueberries, and sweet corn, while maintaining pollinator health in economically important agricultural systems.
- Identify the importance of variability and diversity at local and landscape scales and across States on chemically mediated interactions between pests, crops, and beneficial organisms. Test application strategies for managing this variability.
- Work to find ways to minimize the impact of pesticides and discover new pesticides that reduce the impact on pollinators, herbivores, microbes and natural enemies of pests.
- Exploit knowledge of domestication and breeding history to deploy better strategies to improve crop resilience to novel stressors such as climate change and emerging pests.
- Explore and exploit microorganism mediation of multi-trophic species interactions, including bacteria, fungi and nematodes.
- Broaden utilization a chemical ecology analytical facility for the Northeast to allow researchers ready access to equipment and technical expertise and increase training of High Quality Personnel.
- Conduct Extension and Outreach to facilitate adoption and awareness of science-based chemical ecology to support sustainable production and promote human health and welfare.
The importance of the work, and what the consequences are if it is not done:
As the discipline of chemical ecology matures, knowledge gained in ecological, behavioral and evolutionary studies can be translated into practical and applied pest management. Thus, blending fundamental and applied research enhances the likelihood of sustainable pest management and a reduction in pesticides released into our environment. The consequence of not pursuing sustainable, non-pesticidal management of pests is a continued reliance on insecticides and other pesticides, with potential long and short term adverse effects on our environment for future generations.
Generally, researchers of diverse disciplines converge upon a particular crop or target pest rather than developing management models that cut across a broad range of crops and pests. This multistate project has done the reverse, harnessing the intellectual breadth of chemical ecology practitioners and to focus their interests on agricultural pests and pollinators. Nonetheless, the multi-state team is remarkably diverse, spanning plant breeders, entomologists, applied ecologists, and pathologists. One of our key outcomes is bringing this diverse expertise to a common table annually to promote real-world applications of chemical ecology.
The technical feasibility of the research:
The field of chemical ecology originated nearly 60 years ago with the identification of an insect sex pheromone. That work engendered the applied practice of pheromone mating disruption and pheromone trapping to inform IPM decisions. Since then, it has become clear that understanding how to manipulate agricultural systems to maximize the benefits of beneficial species while minimizing the negative effects of pests requires understanding the community-wide biological activity of toxins and signaling compounds, particularly those coming from crop plants. Insect pests, natural enemies of pests, and pollinators are also part of a community including pathogens of insects and plants and that measures to control pest species can have negative consequences for beneficial members of the agroecosystem. This knowledge will lead to the development of practical and economic tools to suppress agricultural pests and enhance pollination. A concrete example of applications arising from this multistate is research showing which cultivars of wild and domesticated blueberries are most attractive to the new invasive pest, spotted wing drosophila. In another example, strawberry and apple growers have been provided information on the pesticides in the pollen loads of pollinating bees on their farms. Some farmers have been informed that their bees have high levels of pesticides and they have been aided in reducing the use of or select less harmful pesticides. In addition, a pesticide decision-making guide is available freely on the web and many growers across the Northeast are using this to choose the most pollinator-friendly and effective pesticides (https://pollinator.cals.cornell.edu/resources/grower-resources/).
Key to the future technical feasibility of the project has been the group’s success in developing a regionally accessible facility for chemical analysis of plant defenses and pesticide quantities. Maintaining state of the art equipment is expensive and this group has been able to work together to take advantage of special funding opportunities, such as USDA equipment grants, to improve our technical capacity and provide analysis on a sample fee basis. We continue to work with breeders and molecular biologists to link needs on the farm with technological advances in biology. Thus, we are confident of technical feasibility and fruitful knowledge as the discipline matures and as we begin to elucidate the roles of plant genetics, gene expression, and metabolic pathways that control chemical signaling among plants, pests, natural enemies, microbes and pollinators. Additional, emerging pests, new opportunities, and changing membership of the multi-state project allow for rapid deployment of collaborations across the region.
The advantages for doing the work as a multistate effort:
The field of chemical ecology is well represented in various land grant universities within the Northeast and while there are pest problems that are unique to the Northeast, there is substantial overlap in pest guilds within the areas comprising the region. The project has already attracted many leading chemical ecologists from the Northeast and across the country. There are 36 PIs involved, 20 of whom have attended the yearly meetings. In the first meetings, researchers presented the highlights of their research to get to know each other and find points of overlap. At the meeting in 2018 (which also included NYSAES Director Jan Nyrop, and Mary Purcell from the USDA), we specifically discussed ways to strengthen the connection between fundamental discovery and agricultural applications.
Already, the multistate project has been instrumental in allowing researchers to bring in additional resources, with the group bringing in approximately $5 million in grants from diverse sources ranging from the USDA NIFA, the Almond Board of California, Cypress Creek Renewables, Inc, and the IR-4 Minor Crop Pesticide Program. These grants have provided funding to support the chemical ecology multistate project umbrella goals.
Areas advantageous for future multistate efforts have been identified, in addition to continuing many existing projects. These include collaborative work on: 1) emerging non-insect pests, 2) development of new approaches to breeding that include screening diverse pools of cultivated germplasms for quantitative resistance traits; and 3) developing a quantitative framework for understanding the consequences of patchiness in herbivore attack in agricultural systems. Notably, these goals are not specific to a particular crop, but seek to test how chemical ecology approaches can be applied to solve general agricultural problems.
As mentioned above, analytical instrumentation is increasingly a limitation for academic researchers. The equipment is expensive to purchase and maintain and requires a skilled operator, which results in both high initial costs and per sample fees. The regional chemical ecology facility has begun to overcome these hurdles in a cost-effective manner. By focusing on developing techniques that are useful to researchers across the region, groups at many institutions can access the analytical power of a cutting-edge facility with a trained chemist to aid them with the chemical analysis component of their project. This allows many more researchers to incorporate high-level chemical analysis and elucidation of interactions and mechanisms previously out of reach.
What the likely impacts will be from successfully completing the work:
Impacts will continue to be seen in several areas. For example, we are increasing our understanding of how to manipulate mixtures of crop cultivars and other forms of plant diversity to affect the behavior of pests, beneficials and natural enemies to increase crop yield. Active research is aimed at discovering new plant natural products that can reduce pests and increase beneficials. For example, plants with anti-pathogenic properties are being investigated as a way to protect pollinating bees from parasites, and wildflower strips are being designed to increase pollinator health. The effect of insecticides, fungicides and herbicides in the agroecosystem will continue to be tested to discover which chemicals are both effective and safe for non-target organisms. And, crop varieties will be promoted that are the most valuable given the current pest problems in the region.
Related, Current and Previous Work
Substantial achievements were made over the past 5 years; in this section we outline the work that was accomplished as well as work that is incomplete or in need of further investigation.
Previous Objective 1: Develop chemical ecology tools and information to support sustainable agriculture by reducing damage by pests in crops such as potatoes, brassicas, cucurbits, apples, blueberries, and sweet corn, while maintaining pollinator health in agricultural systems.
The work conducted on this Objective included evaluation of plant defense elicitors for pest control, the role of microbes in plant resistance to insects, and plant traits that can benefit pollinators. The group made substantial progress in a wide range of cropping systems important in the northeast, including new target pests that are invasive species. As outlined below, we will continue the work we started and expand to include ornamentals and new emerging pests.
Several studies investigated the role of plant elicitors in protection against insect pests. For example, Stout and graduate student Kraus examined the ability to protect plants from rice water weevil using methyl jasmonate treatments and found protective effects, but also costs measured in terms of reduced plant growth (Kraus and Stout 2019). Rodriguez-Saona tested the efficacy of commercially available plant activators of the salicylate and jasmonate pathways in protecting cranberries against pests directly or by reducing phytoplasma infection (Pradit et al. 2019). Findings show that all elicitors made cranberry plants more susceptible to insects and future work is testing the effects of defense activators on plant nutrient content. Part of manipulating plant defenses for pest protection also involves identifying plant traits that are effective defenses. Karban and colleagues have studied the unidirectional leaf hairs found in many agriculturally important grasses (Karban et al. 2019). They found support for the hypothesis that these hairs usher small insects away from the valuable meristems located at the plant bases and that hairs can be induce by treatment with volatile organic compounds (Karban and Takabayashi 2019). Our future work in this area will proceed in several arenas. One, we will work to develop a predictive framework for when to activate plant defenses using elicitors and how to avoid yield losses is needed. This question particularly benefits from a multistate framework where replicated experiments using elicitors can be conducted across states and crops. Second, this work will to be done with both existing commercially available plant elicitors as well as novel compounds that induce different plant responses. Testing the effectiveness of elicitors across crops and locations will allow us to produce general guidelines on whether this approach is useful.
Researchers investigated the use of behavioral manipulations for pest management. As spotted wing Drosophila is a major pest across the region, the multi-state project has been extremely beneficial in connecting researchers from several land grant institutions to address highly overlapping issues. Rodriguez-Saona worked on the chemical ecology of the new invasive pest spotted wing Drosophila evaluating an attract and kill approach using HOOK SWD Lure-and-kill (ISCA Technologies, Inc), finding that this technique is most effective at lower spotted wing densities. Loeb investigated the role of insects in the transmission of fire blight, a major bacterial disease of pome fruits caused by Erwinia amylavora (Boucher et al. 2019). They detected E. amylovora on or inside several species of Diptera, including the seed corn maggot Delia platura. Adult flies prefer to feed on ooze associated with this disease and then transmit it to uninfected plants. Work is continuing on whether odors are involved in fly attraction to ooze, thereby facilitating acquisition and transmission.
The need to understand the role of microbes in pest management is becoming clear to researchers. Hoover studied the effect of the gut microbiome on lepidoptera and the invasive Asian longhorn beetle Anoplophora glabripennis, showing that larvae have a broad host range in part because they feed on plant tissues low in defenses. Future work in this area will focus on the economically important ornamental crops in the northeast. Kyle Wickings tested whether soil microbes affected chemical cues affecting oviposition choice of a major turf pest, Japanese beetles. The Wickings lab found that soil sterilization reduced oviposition and are now following up on these experiments. Microbial interactions are complex because they can take many forms (direct toxicity, indirect attraction/repulsion of pests or beneficials, or modification of plant-pest interactions through changes in traits. We expect the multi-state program incorporating microbes in applied chemical ecology to expand over the next five years.
In an effort to improve pollinator health, Adler grew and collected pollen from 19 taxa, including cultivated and wild sunflower and tested effects of this pollen against a devastating bumblebee pathogen. Their group reported that all sunflower and goldenrod pollen dramatically reduced this pathogen relative to control pollen (LoCascio et al 2019). They also ascertained what proportion of the sunflower pollen was needed in the diet to be medicinal and determined that it is 50% and that bees that receive sunflower pollen immediately after pathogen infection are more protected than when the medicinal pollen is eaten after infection (LoCascio et al. 2019). Current efforts are examining ways to incorporate medicinal pollen in bee colonies.
Objective 2: Define variability of chemically mediated interactions between pests, crops, and beneficial organisms in terms of plant chemistry, species interactions and landscape factors in the Northeast.
Work so far has focused on within plant and insect sources of variation in interactions. Interactions between responses across tissues within a single plant can have a big effect on pests. Plant induced responses have primarily been studied in leaves, but recent work led by multistate members Whitehead and Poveda in apples and other systems has shown that fruits can also respond rapidly to attack (Whitehead and Poveda 2011), Whitehead et al. in prep). Whitehead is investigating how the microbes on different portions of the apple fruit affect the apples resistance to insects. So far, the variation in microbes across the fruit surface has been documented and the effects on resistance is ongoing. On the insect predator side, Renner is investigating carabids because they are important biological control agents in many cropping systems but little is known about their chemical ecology. Carabids have specialized tissues that store toxic compounds that repel predators, and Renner is investigating their chemical makeup and organization, which will be key in understanding what else these bioactive chemicals due to prey and conspecific predators.
At the landscape level across four states, multistate members Thaler, Chen and Poveda have investigated how populations of the potato pest, Colorado potato beetle vary in their interactions with predators. Preliminary research shows that beetles from landscapes with low complexity have stronger defenses against predators. This work will be followed up on to ask how effective biological control is in simple or complex landscapes. Other work in landscape ecology will study how the farm landscape influences pollination services. Future work in this area will also include a systematic analysis of how landscape composition influences chemically-mediated interactions between plants, herbivores and pollinators; this will be used to guide farms where augmenting these interactions may benefit crop production.
Objective 3: Characterize the non-target effects of pesticides on pollinators, herbivores and natural enemies of pests.
This is an important topic at the intersection of two goals of this multi-state: to reduce the use of pesticides while developing and implementing the use of biorationale pesticides. To achieve this goal, the non-target effects of different pesticides must be understood. Kaplan has developed a pollinator protection program involving several members of the multistate, including Atallah, to minimize effects on cucurbit pollinators. McArt has worked with strawberry and apple growers to provide information on pesticides in the pollen loads of pollinating bees on farms. This knowledge is being used to reduce the use of or select less harmful pesticides. Poveda and students compared the pesticide residues in squash nectar and pollen and the pest suppression efficiency of seed coating treatments compared to post-planting applications; the field and lab experiments have been conducted and data are being analyzed. Hoover found that neonicitinoid-treated cotton seeds had no effect on extra-floral nectar production or composition, and had no effect on parasitoids of fall armyworms feeding on these plants. Levels of neonicitinoid were tested and found to be fairly high, but below the LC50 for the parasitoid. Chen studied whether epigenetic patterns in insects are associated with the evolution of resistance to pesticides (Chen and Schoville 2019, Brevik et al. 2018, Crossley et al 2017, Alyokhin and Chen 2017). Future work in this area will expand to include the discovery of less harmful pesticides, to include the consequences of resistance evolution, and to include how microbes can be manipulated to reduce herbivores or enhance pollinators.
Objective 4: Assess the impact of domestication on plant and animal chemical ecology in agricultural fields and identify unifying patterns of human and natural selection on chemical interactions of crop plants
To provide a robust test of whether increased allocation to yield can alter plant investment in defense, Whitehead and Poveda (2019) examined fruit chemical defense traits and herbivore resistance across 52 wild and 56 domesticated apple lines that vary >26-fold in fruit size. They showed a negative relationship between fruit size and phenolic content, observed across a large number of wild and domesticated lines, supporting the hypothesis of yield–defense trade-offs in crops. Continued studies will seek to identify varieties that have the resistance to insects while maintaining yield. Rodriguez-Saona evaluated the effects of domestication on plant defenses against herbivores in blueberries as a means to target future breeding efforts. They tested the preference of the new invasive pest, spotted wing Drosophila, between wild and domesticated blueberries and discovered that wild berries were more attractive to flies than cultivated blueberries.
Agrawal and cucurbit breeder Mazourek collaborated to utilize existing breeding pools developed in different regions to assess mechanisms of resistance to the major insect pest (Acalyma squash beetles), working towards breeding these traits into more susceptible varieties. Much of the field and behavioral work is complete (Brzozowski et al 2019; Brzozowski et al in review). Genomic selection to identify the genes is on-going. Because the squash bug (Anasa tristis) is an emergent pest in the North East (although already established in the southern USA), they have initiated projects to address using the same cucurbit breeding pools to address resistance to squash bugs. Future work in this area in general will also investigate finding varietal solutions that are robust in the face of climate change and new invasive pests.
Objective 5 Establish a chemical ecology analytical facility for the Northeast to allow researchers ready access to equipment and technical expertise.
The chemical ecology core facility is up and running at Cornell under the direction of Drs. Nico Baert and Scott McArt. The Cornell facility has been expanded to allow external users through a pay-for-service arrangement for multi-state researchers such that a consistent and rigorous protocol can be followed for analyses of phytochemistry relevant to breeding, pesticide residue analysis relevant to non-target effects, and analysis of volatile organic compounds relevant to attraction of pests, pollinators, and natural enemies. The facility has a new LC-MS/MS triple quadrapole and is geared up to run samples to simultaneously identify 260 pesticides, plant hormones (JA, SA, and auxins). Protocols for many plant secondary metabolites have been developed and more are in the process of being developed (terpenoids, alkaloids, withanolides). Future directions are to continue to work with researchers to develop more secondary chemical assays. As part of this effort, the group is submitting a USDA equipment grant to purchase a GC-MS that would be part of this facility. We will also increase use the facility as a training platform for graduate students and postdocs by facilitating researchers from Cornell and other institutions to come to run their samples and learn how to perform LC-MS.
Objective 6 Extension to facilitate adoption and awareness of science-based chemical ecology tools to support sustainable production.
The multistate groups have produced factsheets, proceedings and presentations to facilitate adoption of chemical ecology tools into agriculture. For example, Rodriguez-Saona and Loeb have presented research findings relating to the control of spotted wing Drosophila in Factsheets in conjunction with the Northeast IPM SWD Working Group (Rodriguez-Saona et al 2019a, Loeb et al 2019). Proceedings from Agricultural Trade Shows have been published documenting the efficacy of different traps for monitoring spotted wing (Rodriguez-Saona et al 2019 b, c). And, presentations have also been given at Fruit and Vegetable Trade Shows (Rodriguez-Saona 2019: Atlantic Coast Agricultural Convention and Trade Show, MidAtlantic Fruit & Vegetable Convention, Blueberry Open House). The Mazourek group has presented results on how to breed curcurbits that are resistant to pests to US and global vegetable seed breeders that supply NY growers (Vegetable Breeding Institute Field Days). A lot of work has been conducted to convey information on the non-target effects of pesticides to growers. The McArt lab has spearheaded production of a pesticide decision making guide which is available freely on the web and many growers across the Northeast are using this to choose the most pollinator-friendly and effective pesticides (https://pollinator.cals.cornell.edu/resources/grower-resources/). Kaplan’s Pollinator Protection has presented their research findings on revisiting IPM incorporating pollinators, pests and yield at many venues including the West Central Indiana Beekeepers Association and produced a web based informatic called “Don’t Just Spray- Survey” (https://pollinatorprotection.org/). Whitehead has presented her work on the importance of the apple microbiome at several cider growers meetings including the Virginia Association of Cider Makers Summer Meeting and led a workshop at Virginia Tech Kentland Farm Field Day.
As a last form of extension, the multistate project contributes to the general education of the public through relaying our findings in venues such as the Cornell teachers School, Insectapalooza (3,000 members of the public come and we host tables on pollination and plant-insect interactions). In addition, all labs take seriously the training of postdocs, technicians, graduate students and undergraduates who become educated in chemical ecology approaches to agriculture. We make an effort to attract underrepresented minorities to these positions.
The high monetary cost associated with bringing new pesticides to market, and the recognized economic, environmental and human costs of delivering pesticides to their targets are ample justification for developing alternative tactics to pesticidal control of pests. Specifically, methods that exploit the natural signaling and chemically mediated interactions that occur among crops, pests, and natural enemies can be used to improve integrated pest management and also to facilitate pollinator health and efficacy in agricultural systems. This proposal takes up this challenge by incorporating new frontiers in chemical ecology in agriculture, including the importance of microbes as major contributors to plant-arthropod interactions, which will be achieved in the new Objective 5. We will expand the work on pollination including herbivore-pollinator interactions and the non-target impacts of pesticides on pollinators, and continue to explore emerging pests of economically important crops. We will push the frontier on how crop protection is influenced by factors across scale from the plot to the landscape and State so farmers can understand how their context influences their risks and management options.
Major advances in pest management arose in the 1950s, with the advent of identifying pest pheromones and it is widely recognized that there is still tremendous potential to apply chemical ecology to pest management. The identification of silkworm pheromone in the 1950’s by Butenandt et al. (1959) was a milestone in chemical ecology. Similarly, plant defense by naturally occurring cucurbitacins, and the interplay between resistance and susceptibility to various pests (as well as impacts on cucurbit flavor) was a milestone in breeding for resistance in the 1970s (da Costa & Jones 1971). Chemically mediated interactions among crops and their herbivores and pollinators, largely insects and other arthropods, vary substantially and are highly dependent on the nature of the interaction. There is a wealth of research pointing to the continued possibility of harnessing chemically-based interactions and chemical communication to assist with pest management and pollinator efficacy.
Communication via volatile chemicals-While many plant secondary metabolites such as cucurbitacins, glucosinolates and capsaicins are mostly non-volatile, volatile emissions from plants are thought to play a part in virtually every aspect of a plant’s interaction with its environment. There are numerous reports of pests’ preferences for certain varieties of a crop, but that preference has rarely been attributed to differences in constitutively produced plant volatiles. However, published research by Hoffmann et al. (1996) and new multistate- funded research by Mazourek and Agrawal suggests that for the striped cucumber beetle, there is a strong attraction to certain cultivars or subspecies of Cucurbita pepo independent of the aggregation elicited by the release of a male-produced pheromone. This strongly suggests a quantitative or qualitative difference in constitutively expressed plant volatiles and introduces the possibility of manipulating these volatiles to help the crop avoid attracting an herbivore pest.
In addition to constitutively expressed plant volatiles affecting herbivores, herbivores in return can induce the production of plant volatiles and other secondary metabolites. Herbivore feeding and elicitors in herbivore saliva can elicit or prime both direct and indirect plant defenses (Scala et al. 2013; (Jones et al. 2019). Tumlinson’s group is identifying elicitors in herbivore saliva that induce plant defenses and can be used to develop environmentally friendly pest management strategies. These plant defenses are typically mediated by plant hormones such as jasmonic acid, salicylic acid and ethylene resulting in activation of metabolic pathways that produce secondary metabolites and can also be induced by elicitors in herbivore saliva (Jones et al. 2019). In turn, the metabolites have effects ranging from attracting herbivores to discouraging herbivores, or that are indirectly protective by attracting parasites and predators that feed on the herbivores (Kraus and Stout 2019). Plant induced responses have primarily been studied in leaves, but recent work led by Whitehead in apples and other systems has shown that fruits can also respond rapidly to attack (Whitehead and Poveda 2011), Whitehead et al. in prep). This work also highlights the necessary connection between plant resistance and pollinator attraction as herbivore damage to leaves can induce changes in floral tissues that negatively affect pollination (Glaum and Kessler 2017).
Induced plant volatiles can also act as indirect defenses of plants by alerting natural enemies to the presence of herbivore pests. A metaanalysis by multistate members Rodriguez-Saona and Kaplan showed that across multiple agricultural crops, including cranberries, predators are attracted to the induced plant volatile methyl salicylate (Rodriguez-Saona et al. 2011). When plants were genetically manipulated to produce certain volatiles it resulted in the attraction of natural enemies of the herbivore that would normally induce those volatiles (Kappers et al. 2005, Schnee et al. 2006). Other researchers have found indirect defenses and the attraction of natural enemies (e. g. Agrawal et al. 2002, Thaler et al. 2002, Menzel et al. 2014). However, some argue that manipulating crops to lure natural enemies to the field early enough to be effective control agents may be difficult to achieve and may have some unwanted side effects such as the attraction of predators and parasites that attack the pests’ predators and parasites (Kaplan 2012). The discovery of new elicitors that turn on different suites of plant volatiles, such as studied by the Felton and Tumlinson groups, may lead to methods of inducing plant volatiles that manipulate beneficial natural enemies in a way that increases predation on insect pests.
Understanding how diversity affects crop-pest interactions has been a longstanding goal in agroecology, leading to key discoveries about the benefits of landscape heterogeneity and crop mixtures (Reiss and Drinkwater 2018). For example, collaborative work between Wetzel and Karban showed that variability in plant nutrients reduced the performance of insect herbivores (Wetzel et al. 2016). A key piece missing from our understanding of the role of variability in agroecosystems is that we lack a general understanding of what patterns of variability in crop-pest interactions look like across cropping systems and across geographic areas. Laying the foundation for future work on the role of variability in pest control requires a large-scale, multi-state approach. Farms in the northeast are situated in different landscape contexts, from highly agricultural to a high proportion of natural habitats. This landscape context has a large impact on the abundance and traits of pest species as well as their interactions with beneficial organisms such as natural enemies and pollinators (Grab et al 2019). Understanding how plant-herbivore and plant-pollinator interactions are affected by the landscape is needed to tailor crop management strategies to the environment of the farm.
Applied pollinator chemical ecology
Insect pollination provides vital ecosystem services that sustain agricultural crop yields. Many agricultural crops rely completely on pollinators for successful yields and honeybees are the only managed insect used worldwide for pollination. Successful pollination can be at risk from factors including population declines and diseases, and climate change is disrupting the synchrony of bees and their hosts. Fortunately, there are often native bees to carry out this valuable service. Bartomeus et al. (2013) found that a diverse assemblage of bee species allowed extensive synchrony between bee activity and apple peak bloom due to complementarity among the bee species' activity periods and system stability imparted by differential responses among the species to a warming climate. Despite the potential for successful pollination by species other than honeybees, pollination can be limiting and therefore there are several areas where the field of chemical ecology can contribute to pollinator health and abundance.
There are several goals for achieving successful crop pollination including healthy bees, avoiding transmission of diseases by bees, maintaining attractiveness of flowers to pollinators, and compatibility of plant resistance to pests and pollinator attractiveness. We will use chemical ecology to address these goals. New research also suggests that secondary compounds in flowers can reduce pathogen loads in pollinators (Gherman et al. 2014). Working across MA and NY Adler, McArt and colleagues are using this to find crops cultivars containing secondary compounds that can be planted to rid bees of Crithidia, a lethal bee disease. Floral scents can be used to make crops attractive to pollinators. Bee pathogens may be transmitted via shared floral use, but the role of plant species and floral trait variation in shaping transmission dynamics is almost entirely unexplored. Results of multistate research including Adler and McArt (McArt et al. 2014, Adler et al 2018) suggest that variation among plant species, through their influence on pathogen transmission, may shape bee disease dynamics. Given widespread investment in pollinator‐friendly plantings to support pollinators, understanding how plant species affect disease transmission is important for recommending plant species that optimize pollinator health. Research has shown that greater volatile emissions by unpollinated blueberry flowers resulted in greater attraction of pollinators relative to pollinated flowers (Rodriguez- Saona et al. 2011). Furthermore, the variation in volatile emissions from blueberry flowers depending on pollination status, plant cultivar and time of day suggests a role of floral signals in increasing pollination of flowers. This work can help us select cultivars that are particularly attractive to pollinators. Lastly, many crops contain chemical defenses against herbivorous pests, and can induce chemical defenses that reduce feeding and insect growth. However, defensive chemicals expressed constitutively or induced by herbivory can also occur in floral resources that are consumed by pollinators (Adler 2000). For example, nectar and pollen often contain flavonoids, alkaloids, terpenoids, and other compounds frequently associated with anti-herbivore defense (Palmer-Young et al 2019), which can influence pollinator foraging and health in negative and positive ways (e.g. Koch et al 2019 Current Biology). The consequences of increased resistance to herbivores may have non-target effects on native and managed pollinators, and should be considered for crop management and breeding programs. Future work will discover cultivars and traits that can protect against pests while allowing for successful pollination.
Pesticide non-target effects
Among the multiple factors known to be influencing pollinator health, there is considerable interest in the effect that pesticides are having on bees. Insecticide residues are often found at levels known to influence susceptibility to parasites and pathogens (Alaux et al. 2010; Pettis et al. 2012; Wu et al. 2012), foraging behaviors (Henry et al. 2012; Stanley et al. 2015), and growth and survival of bees (Desneux, Decourtye & Delpuech 2006; Vidau et al. 2011; Henry et al. 2012; Whitehorn et al. 2012). At the same time, fungicide residues are often the most abundant pesticides found in bees and bee products (Chauzat et al. 2006; Mullin et al. 2010; Pettis et al. 2013; Sanchez-Bayo & Goka 2014; David et al. 2015; Frazier et al. 2015; Hladik, Vandever & Smalling 2016; Traynor et al. 2016). McArt lab data support these broader findings regarding fungicides; they have observed that fungicides are the dominant residues in honey bee wax from New York beekeeper colonies (Wheeler et al. 2017a), wax from bumble bee colonies placed in urban, natural and agricultural New York landscapes (Milano et al. in review), and honeybee beebread and mason bee pollen provisions collected during bloom in New York apple orchards (McArt et al. 2017a, Centrella et al. in prep). In addition, in NY and MI, McArt has collaboratively identified the main pollen diets of honeybees—placed in the field to pollinate cucumbers—and wild bees in Michigan (Wood et al. 2018) and quantified the concentrations of pesticides returning to their hive (Wood et al. 2019). A primary finding from this work was that oral exposure to the neonicotinoid thiamethoxam is temporally correlated with collection of pollen from fall-flowering forbs such as goldenrod, and not with crop pollen (e.g., corn) as commonly expected.
Fungicide exposure is not typically considered a major risk for bees since fungicides are substantially less toxic to insects compared to insecticides. However, a growing number of studies have begun to find surprising links between fungicides and bee health (e.g., vanEngelsdorp et al. 2009; Pettis et al. 2012; Huang et al. 2013; Pettis et al. 2013; Bernauer, Gaines-Day & Steffan 2015; Traynor et al. 2016; Mao, Schuler & Berenbaum 2017). We recently found that fungicide usage was the strongest predictor among 24 variables for the loss of declining bumble bee species (Bombus affinis, B. occidentalis, B. pensylvanicus and B. terricola) across the United States (McArt et al. 2017b). Similarly, at the local scale, we have found that fungicide usage before and during bloom in New York apple orchards is a stronger predictor than insecticide usage for wild bee abundance and diversity (Park et al. 2015). In recently published work from Indiana, we also document fungicides as the most prevalent pesticide group occurring on milkweed leaves, potentially affecting the development of monarch caterpillars on their host-plant Asclepias syriaca (Olaya-Arenas & Kaplan 2019).
Importance of microbes in insect and plant health
Microbes can form a variety of associations that can shape interactions between insects, plants, and higher trophic levels. The degree of the association, and the underlying physiology and ecology of the interaction, varies between different insect lineages (Moran et al. 2019; Douglas 2015). In some instances, microbes can contribute substantially to the herbivore through provisioning of nutrients, digestion of polysaccharides, and by hormonal regulation, where disruption of the core membership leads to dramatic fitness consequences to the host. In other cases, relationships are more contextual to what the insect is encountering. Most of our mechanistic understanding of microbial involvement remains in a relatively select number of model species. However, given the prevalence and ubiquity of interactions in the environment, there are likely important ecological functions that these associates play in insect health that can provide insights for managing pest populations. For example, the attractiveness of apple fruits to codling moth, a worldwide pest, depends on fruit colonization by Metschnikowia yeasts (Witzgall et al. 2012). The yeasts act as codling moth mutualists by decreasing mold incidence in the feeding tunnels of larvae and thereby decreasing larval mortality (Witzgall et al. 2012).
The modern crop varieties that form the base of the modern food system appear to be particularly susceptible to abiotic and biotic stress (Yahiaoui et al. 2014, Midega et al. 2016). Indeed, there is growing evidence that domesticated crop plants can be more susceptible to generalist herbivores (Chen et al. 2015). For instance across 29 crops a collaboration involving multistate members Whitehead and Poveda, the majority of the domesticated crop genotypes were less resistant to generalist pests than their wild ancestors (Turcotte et al. 2014, Whitehead et al. 2017). In addition, commercially-bred varieties often perform poorly under abiotic (Yahiaoui et al. 2014, Dwivedi et al. 2016, 2017) and biotic stress (Midega et al. 2016). Given that climate change is predicted to impose greater overall abiotic stress and pest pressure (Deutsch et al. 2018, Aguirre-Liguori et al. 2019), there is an urgent need to understand how crop varieties may differ in chemically-mediated interactions with pests.
New approaches in breeding aim to break the frequent loss of resistance that came along with increased yields. An identified goal is work with diverse pools of cultivated germplasm with distinct breeding histories for discovering new mechanisms of resistance to insect herbivores. Historical dogma in plant breeding as well as entomology is that we look to the genetic diversity of wild relatives of crops for traits to introgress into elite germplasm to address pressing biotic and abiotic challenges (Dempewolf et al. 2017; Tanksley and McCouch 1997). With this approach, more than 2000 biotic stress resistance traits have been identified in crop wild relatives; however, the vast majority of traits identified are for disease resistance, and less than one quarter of these target insect pests (Dempewolf et al. 2017). Thus, strategies for breeding for resistance to insect pests must also be inclusive of secondary centers of diversity, and contemporary breeding pools. The context in which these breeding pools were developed may also better reflect the context of agricultural plant-herbivore interactions than wild systems, where major secondary metabolites (such as cucurbitacins in the Cucurbitaceae and alkaloids in the Solanaceae) may have different effects. In the diverse pools of cultivated germplasm with distinct breeding histories, plant breeders may discover alternative, perhaps quantitative resistance traits. Although of lower value than discrete and complete resistance traits often sought after in disease resistance, such traits are uncommon in insect resistance. Screening material for the most promising, but less obvious traits will benefit by being informed by chemical ecology, and incorporating these traits into agroecosystems will require tools from plant breeding (Brzozowski et al. 2019).
Develop chemical ecology tools, information, and deployment strategies to support sustainable agriculture by reducing damage by pests in crops and ornamentals such as potatoes, brassicas, cucurbits, apples, blueberries, and sweet corn, while maintaining pollinator health in economically important agricultural systems.
Work to find ways to minimize the impact of pesticides and discover new pesticides that reduce the impact on pollinators, herbivores, microbes and natural enemies of pests.
Exploit knowledge of domestication and breeding history to deploy better strategies to improve crop resilience to novel stressors such as climate change and emerging pests.
Explore and exploit microorganisms (including bacteria, fungi and nematodes) that mediate crop – pest interactions.
Identify the importance of local and landscape diversity on interactions between crops, pests, and beneficial organisms.
Broaden utilization of a chemical ecology analytical facility for the Northeast to allow researchers ready access to equipment and technical expertise and increase training of High Quality Personnel.
Conduct Extension and Outreach to facilitate adoption and awareness of science-based chemical ecology to support sustainable crop production and promote human health and welfare.
Nearly all projects will involve a field and laboratory component, with specific, hypothesis-appropriate experimental designs, and shared and coordinated methodologies essential for cooperative data sharing. Research will focus on potatoes, brassicas, cucurbits, apples, blueberries, and sweet corn, and ornamentals and the administrative leadership of the project will maintain lists of the relevant varieties and experiments in order to maximize cross validation and analyses of specific problems in multiple states. Chemical analyses, typically including liquid and gas chromatography, mass spectrometry, or spectrophotometry will be employed in nearly all research projects.
Objective 1: Research will employ natural elicitors of plant resistance (jasmonic acid, salicylic acid, and related compounds), and the screening of varieties for traits relevant to pest management and breeding. When chemical signaling between species is related to non-volatile chemical compounds such as cucurbitacins or similar agents, liquid chromatography- mass spectrocsopy (LC-MS) will be employed to identify and quantify the signal compounds. Where signaling is deduced to be caused by plant or insect volatile emissions, standard and published methods typically include adsorption of candidate volatiles on carbon traps or by solid phase micro-extraction (SPME). Subsequently candidate compounds are eluted/desorbed from the collection media and passed through gas chromatography coupled with flame ionization detection with the chromatography column split to allow electroantennographic detection (EAD) by an insect pest, pollinator or natural enemy. This will allow inference regarding which classes of compounds cause neurological responses in the insect receiving the signal. Those compounds causing neurological responses in the insects are then typically identified by gas chromatography coupled with mass spectrometry. Once candidate signaling compounds have been identified by antennographic detection and subsequent determination of molecular formulae, behavioral bioassays will be conducted. This is an absolute necessity because neural stimulation does not necessarily translate into a behavioral response; it merely indicates that the insect may be affected by the signaling compound. Behavioral assays will typically run the gamut of choice assays such as y-tube, static or multi-arm olfactometers, wind tunnels, and locomotion compensators. Other choice tests will be conducted in small-plot field trials where plants with and without the signaling compounds of interests are offered as choice and no-choices options to target pests and pollinators.
Objective 2: Field experiments with replication in different states and geographic locations will be conducted to assess the variability of chemical signaling between pests, crops, and beneficial organisms in terms of plant chemistry, species interactions and landscape factors in the Northeast. Using methods described above as well as others as appropriate, trials will be conducted using methods standardized among cooperating states so that the data are robust among the regions and amenable to meaningful analyses or meta-analyses. Typically these will consist of multiple varieties, and in different agricultural contexts (in different states, or nested among different landscapes), while measuring and quantifying impacts on pests, pollinators, and natural enemies. This objective will also employ GIS-based landscape level analyses to complement experimental work.
Objective 3: We will characterize the non-target effects of pesticides on pollinators, herbivores, and natural enemies of pests including evolutionary effects that are relevant to pest management and pollinator health. Non-target effects will be conducted on farms, experimental fields, and laboratory trials. Analysis of pesticides by mass spectrometry will be critical, as will behavioral, performance, and genetic analysis of pests, pollinators, and natural enemies affected by insecticide or other pesticide exposure. In particular for pollinators such as bumblebees, there will be a coordinated multistate effort to gather pollen collected by the pollinators using methods standardized among cooperators. Subsequently, the pollen will be analyzed for pesticidal contaminants by using a common analysis facility as detailed for Objective 6. The effects of sub-lethal, chronic exposure on pollinators such as bumblebees and other non-domesticated bee pollinators will be quantified in terms of behavioral and fitness changes relative to control colonies. To determine if secondary compounds in nectar are deterrent or harmful to pollinators, colonies of the bumblebee Bombus impatiens will be used for foraging trials and microcolonies used to examine effects on bumble bee health and reproduction.
Objective 4: The impact of domestication on plant and insect diversity in agricultural fields will be evaluated in replicated experimental designs that compare crops and their wild progenitors. Such trials will examine the differences between crops and wild-types and will allow us to quantify aspects of phytochemistry that affect the attraction of pests, pollinators, and natural enemies. Studies that employ molecular genetic methods to determine which genes are affected and which are expressed will help expedite resistance breeding by focusing on specific genes and functions that control the chemical interactions that occur among species. The goal of this objective is to identify novel targets and methods for manipulating crop phytochemistry for the purpose of crop resistance and pollination efficacy. Ultimately this will help expedite the breeding process, will lead to the discovery of new mechanisms of resistance to pests, and will generate breeding lines that manipulate and exploit the crops’ phytochemistry to control pests and facilitate pollination.
Objective 5: Strategies to evaluate insect associated microbes typically use culture collections and culture-independent technologies (Mason et al. 2019). To initially assess the membership and putative functions, 16S rRNA amplicon sequencing and metagenomics provide a route to establish core microbes present within a given group of insects. These data can be leveraged by culturing on various types of microbial growth media to perform manipulative experiments. Manipulations can be accomplished by adding microbes of interest to sterile substrates (e.g., gamma irradiated foliage), followed by assessment of insect or plant performance, immune responses, and changes to signaling pathways (e.g., Mason et al. 2019; Pan et al. 2018; Wang et al. 2019).
Objective 6: The facility has a new LC-MS/MS triple quadrapole that is very sensitive for the detection of pesticides, plant hormones, and many secondary metabolites. Our scaled-down protocol is highly efficient; for example, we recently detected pesticide residues in extracts of individual bee midguts and we can detect insect hormones at much lower levels. We will continue developing protocols for secondary metabolites in the crops multistate researchers are studying. We will use our collaborative relationships to increase use the facility as a training platform for graduate students and postdocs. We will facilitate researchers from Cornell and other institutions to come to run their samples and learn how to perform LC-MS.
Objective 7: The Project will continue to execute a program to disseminate relevant findings via various outlets to facilitate adoption and awareness of science-based chemical ecology tools to support sustainable production. Please see Section VII Outreach Plan for detailed description of our methods.
Measurement of Progress and Results
- The project will result in the conversion of research-based knowledge of chemical ecology into tools useful to supporting sustainable and economically sound pest and pollinator management in agricultural systems.
- It will generate data and knowledge regarding the role of chemical communication within and among species of crops, pests, and pollinators in landscapes with an agricultural component.
- It will also generate data and applied knowledge by measuring and quantifying pesticide loads and their effects on pollinators and natural enemies of agricultural pests of importance in the Northeastern Region.
- The project will measure and quantify how crop domestication affects the interactions among agricultural crops and their pests, pollinators and natural enemies.
- The strong presence of chemical ecology researcher laboratories in the Northeast Land Grant Universities will facilitate the coordination, aggregation, sharing, and financial support of analytical equipment to be used among cooperating researchers in the Northeastern Region so that standardized methods and lower-variance data can be generated and utilized among various cooperative research projects.
- There will be annual and continued delivery of research updates to the relevant stakeholder community through open meetings, published proceedings and reports published in peer reviewed publications, trade journals, eXtension, appropriate electronic media and various other electronic avenues.
Outcomes or Projected Impacts
- The overarching objective of this project is to develop novel, cutting-edge and economically attractive approaches that will provide options and allow growers to integrate environmentally friendly, non-pesticidal control of various agricultural pests and improve management of natural enemy and pollinator services.
- We will provide a greater understanding of the ecology of pests, pollinators and natural enemies and this will assist with generating recommendations for a more integrated approach to pollinator and pest management. Increased knowledge is likely to help conserve important pollinator and natural enemy populations and improve their services in agriculture and other ecosystems.
- This project represents a collaborative network of researchers. It will facilitate and expedite cooperation among researchers in the field of chemical ecology, and focus the application of fundamental and basic science on priority problems in agriculture.
- Cooperation and coordination among researchers with a common interest, shared equipment, and shared facilities will allow development of standardized protocols within particular projects and will maximize the impact of the research by generating highly consistent data that will generate meaningful inference and be suitable for future data-mining and meta-analyses.
- The project will facilitate the surveillance, collection and maintenance of population data for establishment of baselines and assessment of pollinator health in the Northeast and elsewhere.
- The knowledge generated by coordinated research will facilitate and expedite plant breeding for enhanced pest resistance and pollinator efficacy by providing explanatory mechanisms for plants responses to pests and pollinators. Coupled with molecular methods that identify pathways for signal chemicals, plant breeders will be able to focus on target genes during the selection and crossing process. The outcome will be horticulturally acceptable crop varieties with enhanced productivity in the face of herbivores.
Milestones(2020):• Roll-out of this revised Multistate Project and solicitations for new participants. • Meeting of Executive Committee and potential participants to establish project work plan. • Commencement of research in model or target cropping systems by participants beginning FY Oct. 1, 2020 • Establishment of standardized protocols for inter- and intra- state collaborative projects for a) pest management and b) pollinator health objectives. • Compilation and distribution of available chemical analytical protocol’s list to participants. • Project participants' organizational meeting and mini-symposium to present and discuss research and developments.
(2021):• Project participants' organizational meeting and mini-symposium to present and discuss research and developments. • Annual business meeting will be held to discuss developments or changes in project objectives, etc. • Establishment of pest management and pollinator sub-committees to guide research directions in each aspect. • Education and outreach efforts will be initiated pending success in research commitments.
(2022):• Integration of any new participants into project plans. • Annual business and participants meeting to discuss developments or implement changes in project execution, updates to equipment services, dovetailing of research efforts, etc. • Publish and disseminate via outreach avenues any relevant findings generated by project.
(2023):• Initiate and organize symposium to present findings on integration of chemical ecology and agricultural priority issues to be combined with a relevant annual conference of entomology, ecology, pollination, etc. • Publish and disseminate via outreach avenues any relevant findings generated by project.
(2024):• Conduct self-assessment and review of the project as a means to prepare for project renewal pending participant and stakeholder consensus that the project has generated sufficient returns to warrant renewal. • Continue publication and outreach dissemination.
Projected ParticipationView Appendix E: Participation
Several members of the project have Extension appointments and are involved in field demonstrations and outreach efforts related to the sustainable management of various agricultural pests, pests’ natural enemies, and pollinators. Many members interact and disseminate information regularly with stakeholders from various sectors of the economy such as farmers, government agencies, agricultural professionals, commodity groups and researchers in related disciplines. Traditional extension meetings and educational programs conducted by Extension personnel will be held with producers, industry, consultants, and regulators to discuss findings and share information. Those participants with teaching appointments will be able to include current research generated by this project to inform undergraduate and graduate students of cutting edge developments in the field of chemical ecology and as it relates to agricultural issues.
Our results and conclusions will be communicated by various methods including but not limited to:
1) sharing annual reports among participants at our annual meeting;
2) refereed research publications with differing target audiences;
3) publications of newsletter articles, factsheets, blogs, bulletins, etc;
4) non-refereed commodity and industry publications;
5) oral presentations, including webinars, for relevant stakeholders;
6) oral presentations at national and regional technical and scientific meetings;
7) twilight meetings on grower farms.
Additionally, several members of the project have strong connections to the Northeastern IPM Center, the Pennsylvania State IPM Program, the NJ State IPM Program, and the NY State IPM Program. The Project will cultivate an active dissemination program that utilizes the strong media presence that those agencies have already established. The Northeastern IPM Center fosters the development and adoption of integrated pest management for economic, environmental, and human health benefits. Stakeholders work with NEIPM to identify and address regional and global priorities, whether for research, education, or outreach. The Center's efforts are organized under five signature programs where leadership and advisory bodies see the greatest need. At present, the areas of focus for the programs are IPM and organic systems, rural and urban IPM, climate change and pests, next generation education, and advanced production systems. The print version of the Center’s IPM Insights newsletter reaches over 4,000 people quarterly. In the past year, the IPM Center has published IPM Insights in e-book format, in addition to print, PDF, and web versions. NEIPM content is featured in media outlets including Pest Control Technology, Consumer Reports, and Entomology Today. The NortheastIPM.org website links to more than 250 IPM-related organizations while the e-mail listserv reaches approximately 3,500 people. We plan to continue working with the NEIPM Center to promote stakeholder adoption of pest management practices based on chemical ecology principles.
Organization of the project is delegated to an Executive Committee comprising an Administrative Advisor, Chair, Secretary and Representative at Large. The Administrative Advisor will be the Director of New York Agricultural Experiment Station in Ithaca NY and the remainder of the committee will be elected by and from regional project membership. Excepting the Administrative Advisor, Executive Committee members will hold a two year appointment. The Representative at Large will succeed the Secretary who will in turn succeed the Chair. It will be the responsibility of the Chair to prepare technical and executive meeting agendas, preside at meetings, and prepare an annual progress report on the research activities of the regional project. The Secretary duties will be to record the minutes of technical and executive committee meetings and perform other duties as necessary. The Representative at Large will assist both Secretary and Chair with their responsibilities as necessary. Subcommittees may be named by the Chair as needed for specific assignments such as developing new project outlines for continuing the project, to prepare publications, or other assignments. An annual meeting of the full Executive Committee will be held to summarize and critically evaluate progress, analyze results, and plan future activities, reports, and publications.
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