Broad-spectrum chemical insecticides continue to be the mainstay for the control of arthropod pests in most agricultural systems as well as natural and urban landscapes. While several chemical pesticides are capable of rapidly killing various pests, heavy reliance on their use has generated significant problems including safety risks to human and environmental health, negative impact on beneficial arthropods, outbreaks of secondary pests which are normally held in check by natural enemies, decrease in biodiversity, and increased risk of insecticide resistance. Several bacteria, fungi, nematodes, and viruses attack a variety of arthropod pests and multiple species of entomopathogens are commercially available as biopesticides (Lacey, 2016). In the last two decades or so the market has also improved and currently, there are about 400 registered biopesticides (derived from natural materials including animals, plants, microbials, and some minerals) in the U.S. (Arthurs and Dara, 2019).

Recent studies have also indicated that entomopathogenic microbials manage arthropod pests and improve soil and enable plant pathogen management. These microbials also play disease-antagonizing roles and improve overall plant growth and health (Dara, 2019). Although, these are majorly employed in the food production system, lately, the employment of entomopathogenic microbials is being expanded to manage veterinary arthropods as well (Ebani and Mancianti, 2021).

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. One viable alternative to chemical insecticides is the use of microbial control agents. In contrast to chemical insecticides, microbial control agents are generally not harmful to humans or the environment, and have minimal or negligible potential to cause resistance or harm non-target organisms. This project focuses on the development and advancement of 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 National Association of State Universities and Land-Grant Colleges (NASULGC) 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. Many have specifically identified the use of entomopathogens as a priority. Some examples that list the development of entomopathogens as a priority include pecan, peaches, apples, grapes, blackberry, tomato, and coffee (http://www.ipmcenters.org/).

Microbial control research and application has had major impacts on IPM during the past fifty years. The commercialization of Bacillus thuringiensis (Bt) products, including Bt-transgenic plants, is probably the most notable and commercially significant. New discoveries of suitable entomopathogens and advances in their production have facilitated the commercialization of numerous products. Although there has been a significant increase in biopesticide sales and research, microbial control is not considered as a major choice of pest management in many cropping systems, especially in conventional production (Leng et al., 2011; Sinha, 2012; Lacey, 2016). However, recent estimates suggest that biopesticides will become the fastest-growing crop protection market sector globally, with growth greatly exceeding conventional chemical insecticides (Glare et al. 2012). For example, in the USA biopesticides are projected to achieve a compound annual growth rate of 14.7% from 2020 to 2025, with sales reaching $8.5 billion (Markets and Markets). Thus, there is an urgent 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. Therefore, 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 allow for novel discovery, identification, and development of entomopathogens previously overlooked or out of reach. The key challenges that limit 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 applied pest management. The project objectives will address pest issues in large acreage crops, orchards, small fruits and vegetables, and urban areas, landscapes, and nurseries. The consequences of not doing the proposed research include increased chemical pesticides in the environment (risking the health of humans and other nontargets) and increased 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 fornicatus), spotted wing drosophila (Drosophila suzukii), redbay ambrosia beetle (Xyleborus glabratus), red imported fire ant (Solenopsis invicta) and spotted lanternfly (Lycorma delicatula) pose a serious threat to several important hosts in agriculture, orchard, urban, landscape, and nursery systems. Entomopathogens will also be of significant importance in non-agricultural situations where chemical pesticide use is undesirable and poses a higher human or environmental risk.

Given that the research needs indicated above are common to numerous commodities across the US, a cooperative multi-state approach is demanded to provide broad impact solutions that are widely applicable. Entomopathogens and their pest insect hosts are not limited by artificial boundaries. Therefore, tests of efficacy, persistence, safety, resistance management and other parameters must be conducted under different sets of environmental conditions across state lines. Protocols must be developed and standardized for the diverse types of research being proposed. Thus, to be successful in fulfilling the objectives of this project proposal, multi-state cooperative research among universities, USDA, and industry partners is required.

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 numerous cropping systems; and, given the broad nature of the research, we anticipate significant knowledge transfer to additional crops during the project period. Foremost, the proposed research will facilitate transition away from the reliance on chemical insecticide usage by providing effective and environmentally friendly alternatives. Further development of insect pathogens for use in pest management programs will fill vital gaps in pest management caused by removal of broad-spectrum chemicals. This 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. Additionally, microbial control plays an important role in several market sectors, including organic crops, and in the control of invasive pests. The proposed project will improve quality of life by providing farmers tools to manage arthropod pests without risk of poisoning, and by providing the public with food containing less chemical residue. Economic opportunities will be created by enhancing the biological control industry and improving the productivity of various crops. The broad and unique expertise represented by our working group will enable us to achieve our ambitious objectives. This project strongly addresses several US agriculture and SAAESD Priority Areas, particularly Priorities 1, 4, and 5, i.e., 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.