Location: Crop Bioprotection Research2016 Annual Report
Objective 1. Utilizing transcriptomics to link gene function to fungal morphogenesis, develop liquid culture methods for producing propagules of fungal biocontrol agents such as Metarhizium spp., Beauveria bassiana, and Mycoleptodiscus terrestris by optimizing nutritional and environmental conditions during fungal growth for optimal biocontrol efficacy and storage stability to control pests in agricultural, urban, and natural ecosystems. Objective 2. Develop novel fungal formulation technologies through the selection and application of innovative processes and ingredients that lead to improved storage stability, product delivery, field stability, and efficacy of fungal pathogens for biocontrol of insects [Beauveria bassiana, Metarhizium spp., and Isaria fumosorosea] and weeds [Mycoleptodiscus terrestris]. Objective 3. Identify, chemically and behaviorally characterize, and deploy natural insect semiochemicals (pheromones/kairomones and plant volatiles) with microbial biocontrol agents for management of important agricultural insect pests such as brown marmorated stink bug and coffee berry borer.
Our approach to the development of production methods for fungal biocontrol agents will focus on the use of liquid fermentation techniques. We will identify defined or semi-defined media that support the growth of our fungal biocontrol agents. Propagule form yield, storage stability, and biocontrol efficacy are critical “fitness” factors that will be considered during medium optimization Initially, we will focus on producing propagules of fungal biocontrol agents such as Metarhizium spp, Beauveria bassiana, and Mycoleptodiscus terrestris. We also will use transcriptomics to identify pathways that may impact these factors. We will evaluate the impact of culture harvest techniques, stabilization processes, and formulation ingredients on the physical characteristics, biological activity, storage stability, and field efficacy of selected biocontrol agents. Also, we will identify and chemically characterize insect attractants and deterrents and evaluate formulations for management of important agricultural insect pests such as the brown marmorated stink bug, coffee berry borer, polyphagous shot hole borer, and tea shot hole borer.
Significant progress was made in FY16 on Objectives 1 and 2 related to the production and formulation of microbial agents for controlling insects. Under Objective 1, ARS scientists at Peoria, Illinois, continued work on developing and optimizing liquid culture production processes for fungal spores, ideal for insect control as foliar spray applications, and for fungal microsclerotia, fungal compositions ideal for use in granular formulations. Production and stabilization processes for microsclerotia of the insect-killing fungus Metarhizium were refined and this patented ARS technology has been licensed by and is being transferred to an industrial partner for commercial development. A patented ARS liquid culture production process for microsclerotia of the weed-killing fungus Mycoleptodiscus terrestris continues to be evaluated for control of the aquatic weeds Eurasian water milfoil and hydrilla. The use of microsclerotia of M. terrestris has garnered significant industry interests, and shows promise as a non-chemical bioherbicide for use in U.S. lakes and waterways. Liquid culture fermentation methods were developed for the rapid production of high concentrations of blastospores of the insect-killing fungi Beauveria bassiana and Isaria fumosorosea. Both of these bioinsecticides are used extensively worldwide for the control of whiteflies, aphids, and other important insect pests. There is significant industry interest in this ARS patent-pending production process due to the high blastospore yields coupled with excellent desiccation tolerance, shelf life, and biocontrol efficacy. Trichoderma is a fungal biocontrol agent used world-wide for the control of plant root diseases and for improving plant health. Our patent-pending liquid culture production processes for Trichoderma microsclerotia represent major advancements in the development of this commercially-important microbial biocontrol agent. Research continued on the development of liquid culture production processes for the bioinsecticidal fungus Hirsutella citriformis in collaboration with ARS and Mexican scientists. Hirsutella citriformis has shown promise for controlling the Asian citrus psyllid. Under Objective 2, ARS scientists at Peoria, Illinois, developed drying and formulation processes that optimized the stability and efficacy of blastospores of Beauveria and Isaria. The blastospore formulations are excellent for spray applications on plant surfaces for control of whiteflies, aphids, and thrips. Our dried formulations of Beauveria blastospores have shown excellent storage stability at room temperature. These formulation studies demonstrated the importance of water activity and storage atmosphere in optimizing the shelf-life of fungal blastospores. Progress continues on developing and testing blastospore formulations of the bioinsecticide Isaria fumosorosea for use in controlling the Asian citrus psyllid. ARS scientists at Peoria, Illinois, have also made substantial progress in developing shelf-stable, granular formulations of Metarhizium microsclerotia for use in controlling soil-dwelling insect pests including white grubs in turf, corn rootworm larvae, and other important insect pests in collaboration with university and ARS scientists. Collaboration continues with university scientists on the development of hydromulch-based formulations of Metarhizium microsclerotia for control of the Asian longhorned beetle.
1. Stable fungal bioinsecticide. The insect-killing fungus Beauveria bassiana is used world-wide as a non-chemical control agent (bioinsecticide) for many serious insect pests including whiteflies, aphids, and coffee berry borers. Currently, spores of B. bassiana, the active ingredient in this bioinsecticide, are produced by growing the fungus on moistened grains and harvesting the spores from the surface of this solid substrate fermentation. Solid substrate spore production has limited the commercial use of this bioinsecticide due to quality control issues, long production times, high labor requirements, and difficulties in process scale-up. ARS scientists in Peoria, Illinois, and international collaborators, have developed a rapid, low-cost method for mass producing the yeast form (blastospore) of B. bassiana using liquid culture fermentation. Blastospores of B. bassiana were shown to be more effective than solid substrate-produced spores in infecting and killing whiteflies. These studies showed that stable blastospores of B. bassiana can be economically mass produced, formulated, and packaged using commercially-available industrial processes. The commercial adoption of these low cost, patent-pending production, formulation, and packaging methods for blastospores of B. bassiana will hasten the widespread use of this environmentally-friendly bioinsecticide in row crops, horticulture, glasshouses, and urban environments.
Goble, T.A., Gardescu, S., Jackson, M.A., Hajek, A.E. 2016. Evaluating different carriers of Metarhizium brunneum F52 microsclerotia for control of adult Asian longhorned beetles (Coleoptera: Cerambycidae). Biocontrol Science and Technology. 26(9):1212-1229. doi: 10.1080/09583157.2016.1192103.
Dito, D.F., Shapiro-Ilan, D.I., Dunlap, C.A., Behle, R.W., Lewis, E.E. 2016. Enhanced biological control potential of the entomopathogenic nematode, Steinernema carpocapsae, applied with a protective gel formulation. Biocontrol Science and Technology. 26(6):835–848.
Cooperband, M.F., Stouthamer, R., Carillo, D., Eskalen, A., Thibault, T., Cosse, A.A., Castrillo, L.A., Vandenberg, J.D., Rugman-Jones, P.F. 2016. Biology of two members of the Euwallacea fornicatus species complex (Coleoptera: Curculionidae: Scolytinae), recently invasive in the U.S.A., reared on an ambrosia beetle artificial diet. Agricultural and Forest Entomology. 18:223-237. doi: 10.1111/afe.12155.
Mascarin, G.M., Jackson, M.A., Behle, R.W., Kobori, N.N., Delalibera Junior, I. 2016. Improved shelf life of dried Beauveria bassiana blastospores using convective drying and active packaging processes. Applied Microbiology and Biotechnology. 100:8359-8370. doi: 10.1007/s00253-016-7597-2.
Goble, T.A., Gardescu, S., Fisher, J.J., Jackson, M.A., Hajek, A.E. 2016. Conidial production, persistence and pathogenicity of hydromulch formulations of Metarhizium brunneum F52 microsclerotia under forest conditions. Biological Control. 95:83-93.
Behle, R.W., Goett, E.J. 2016. Dosage response mortality of Japanese beetle, masked chafer, and June beetle (Coleoptera: Scarabaeidae) adults when exposed to experimental and commercially available granules containing Metarhizium brunneum. Journal of Economic Entomology. 103(3):1109-1115. doi: 10.1093/jee/tow080.