S149: Discovery and development of natural products for controlling weeds and pests

Natural products from plant and microbial sources can be successfully used for the development of new biopesticides with good activities against plant pathogens, insects, nematodes and weeds. Previously unknown chemistries and novel modes of action make these products very attractive for improved efficacy and resistance management in integrated pest management programs. Marrone Bio Innovations (MBI) has a discovery screen to identify natural products from plants and microorganisms with activity against insects, weeds, plant pathogens and plant parasitic nematodes. From this screen, MBI has discovered two herbicidal natural products, one from a bacterium and one from a pepper plant and an insecticidal natural product from a new species of bacterium. Also, the company has submitted to the EPA's Biopesticide Division a bioinsecticide, a bioherbicide and a product for controlling invasive zebra and quagga mussels. The natural products from these biopesticides will be discussed, including a family of novel molluscicidal compounds from a Pseudomonas fluorescens strain. Often, natural product compounds from microorganisms and plants are complex structures and not easily synthesized. We have found a diversity of structures, including ones that are easily synthesized and others that are more complex or are comprised of complex mixtures of multiple compounds that are necessary for pesticidal activity.