Broad-spectrum chemical insecticides continue to be the mainstay for control of arthropod pests in most agricultural systems, as well as in natural and urban landscapes. Several chemical pesticides are capable of rapidly killing various pests, but heavy reliance on their use has generated substantial problems including safety risks to humans, negative impacts on beneficial arthropods, outbreaks of secondary pests, which are normally held in check by natural enemies, decreases in biodiversity, and increases the risk of insecticide resistance.  Numerous bacteria, fungi, nematodes, and viruses attack a variety of arthropod pests infesting agricultural and urban landscapes.  There are multiple species of entomopathogens that are commercially available as biopesticides which produce fewer negative consequences in the environment (Lacey, 2017). 

Changes in pest management programs, such as the reduction in organophosphate use dictated by the Food Quality Protection Act (FQPA), and proposed legislation by the EPA regulating the use of neonicotinoids to protect pollinators (Suryanarayanan, 2015) necessitate the development of new management tactics that are environmentally sound and compatible with current production and integrated pest management (IPM) practices. In many agricultural and natural systems, viable alternatives to chemical insecticides are microbial control agents.  In contrast to chemical insecticides, microbial control agents generally are not harmful to the environment, have minimal potential to select for resistant populations, or injure non-target organisms. The focus of this project is to develop and advance entomopathogens for biological pest suppression. 

Development of microbial control tactics using entomopathogens is of great importance to US agriculture. The Experiment Station Committee on Organization and Policy (ESCOP), and Association of Public and Land Grant Universities (NASULGC, APLU) have identified environmental stewardship, including the need to decrease chemical pesticide use, as a primary agricultural challenge in the US. Furthermore, most stakeholder groups developing strategic plans for pest management throughout the U.S. have identified biological control as a major research need, and many have specifically identified use of entomopathogens as a priority. Some commodities that list the development of entomopathogens as a priority include pecan, peaches, apples and grapes (http://www.ipmcenters.org/).

Microbial control research and application has demonstrated major impacts on integrated pest management (IPM) during the past fifty years. The commercialization of Bacillus thuringiensis (Bt) products, including Bt-transgenic plants, is probably the most notable and commercially important event. New discoveries of effective entomopathogens and advances in their production have facilitated the commercialization of numerous products. Although there has been an increase in biopesticide sales and research, microbial control generally is still not considered as a primary strategy for pest management in many crops, especially in conventional production systems (Leng et al., 2011; Sinha, 2012; Lacey, 2016).  However, recent estimates suggest that biopesticides could become the fastest-growing crop protection market sector globally, greatly exceeding the growth of conventional chemical insecticides (Glare et al., 2012).  Biopesticide sales in the US are projected to achieve a compound annual growth rate of 17.4% from 2016 to 2022, with sales reaching $1.25 billion (Markets and Markets, 2016). Thus, there is a need to expand microbial control research and incorporate microbial control options into integrated pest management (IPM) strategies in order to maintain global competitiveness of US agriculture.  Additional research is required to expand and complement the expected increase in demand and use of entomopathogens as vital components of IPM. New scientific tools, including molecular markers, genomics, and in vitro production techniques will allow for novel discovery, identification, and development of entomopathogens for IPM.  For entomopathogens to be incorporated into existing IPM practices, results to support science-based recommendations are necessary.  

The key challenges that limit the implementation of microbial control for arthropod pests will be addressed in this project including: enhancing efficacy through strain discovery and improvement, advancing production and delivery, integration with existing management techniques, conservation of endemic entomopathogens, and gaining greater understanding of fundamental entomopathogen biology and ecology to further improve pest management. The project objectives will address pest issues in large acreage crops, orchards, small fruits and vegetables, urban landscapes, and nurseries.  The consequences of not accomplishing the proposed research may increase use of chemical pesticides in the environment (risking the health of humans and other nontargets) and allow greater crop losses due to endemic and invasive pests. In addition to numerous endemic pests, several invasive pests such as the Asian citrus psyllid (Diaphorina citri), Bagrada bug (Bagrada hilaris), brown marmorated stink bug (Halyomarpha halys), polyphagous shot hole borer (Euwallacea fornicates), and spotted wing drosophila,(Drosophila suzukii) pose a serious threat to several important hosts in agricultural, orchard, urban, and nursery systems.  Entomopathogens are critically important in non-agricultural situations where chemical pesticide use is undesirable and poses a higher human or environmental risk.

Given that these research needs are distributed across numerous US commodities and native environments, a cooperative multi-state approach is justified to provide broad impact solutions that are widely applicable. Entomopathogens and their insect pest hosts are not limited by artificial boundaries. Therefore, entomopathogen efficacy, persistence, safety, resistance management and other parameters must be evaluated under in a range of environments across numerous states. Protocols must be developed and standardized for the diverse types of research being proposed. Multi-state cooperative research among universities, USDA, and industry partners is essential to be successful in fulfilling the objectives of this project proposal.  We acknowledge the wide breadth of opportunities for collaborative research projects, but also recognize that this project will allow communication from numerous participants with expertise with entomopathogens in different agricultural and native environments. Participants in the project will share information and resources, participate in cooperative funding prospects, and evaluate progress of individual and group research projects.   

We anticipate that the project will produce substantial benefits for both producer and consumer stakeholder groups. Stakeholders will include farmers, pest control advisors, biopesticide industry, the scientific community, and the general public. Experiments will be conducted in cropping and natural environments. Given the broad nature of the research, we anticipate considerable knowledge transfer to additional crops/settings during the project period. Foremost, the proposed research will facilitate transition from a reliance on chemical insecticide usage by providing effective and environmentally-friendly alternatives. At a minimum, results from the project will be integrated into existing IPM programs as additional tools.  Development of entomopathogens for use in IPM will fill vital gaps caused by the loss of broad spectrum chemical control products. This strategy is of particular importance in specialty crops that have few remaining pest management options. Furthermore, as new pest assemblages arise, novel microbial control tactics will contribute substantially to the development of innovative IPM programs.  Microbial control products already are important tools in several commodity sectors, including organic crops, and for the control of invasive pests. The proposed project will improve quality of life by providing farmers additional tools to manage arthropod pests without negative human and environmental risks, and by providing the public with food containing lower levels of synthetic chemical residues. Economic opportunities will be created by enhancing the commercial aspects of biological products and improving the productivity of various crops.

This project has broad and unique expertise represented by a working group from across the US which will enable us to achieve the proposed objectives. This project strongly addresses several US agricultural and Southern Association of Agricultural Experiment Station Directors (SAAESD) priority areas, particularly priorities 1, 4, and 5 (Developing greater harmony between agriculture and the environment; establishing an agricultural system that is highly competitive in the global economy, and enhanced economic opportunity and quality of life for Americans).