Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings
Publication Acceptance Date: 1/29/1999
Publication Date: N/A
Citation: Interpretive Summary: Alternative methods to agricultural chemicals for insect control are very much desired out of concern for their impact on human health, wildlife and the environment. Augmentation of insect diseases with bacteria, viruses, fungi, and other microbes is a method of insect control that has never been fully explored for control of sunflower insect pests. This study describes our initial efforts to identify disease causing bacteria and fungi in the environment of a sunflower insect pest. So far, we have found some known insect pathogens, non-insect pathogens, and a bacterium that may counteract the disease potential of some insect pathogens. To conduct this type of research, however, it is highly desirable to put in place a method for routine identification of microorganisms based on readily available molecular technology.
Technical Abstract: Cultivated sunflower is an important oil crop that was planted on an estimated 2,852,000 acres in 7 states of the North American Great Plains in 1998. Control of sunflower insect pests is primarily chemical. Concern for the impact that chemicals have on human health, the environment, and the quality of the oil has lead to increased research on alternative methods of control. Pathogenic microbes or their products have great potential for the control of insect pests. There is very little information concerning microbial control of sunflower insect pests. The objective of this study is to determine the prevalence of insect pathogens in the environment of a sunflower insect and to find new pathogens if possible. We have found the following microorganisms: Serratia marcescens, Beauveria bassiana, Klebsiella pneumoniae, Cedecia lapagei, Salmonella, Pseudomonas fulva, Xanthomonas maltophilia, Pseudomonas fluorescens, Bacillus thuringiensis, Enterobacter sakazakii, Pseudomonas corrugata, Enterobacter sakazaki, Enterobacter gergoviae, Pantoea agglomerans. Of these, S. marcescens, B. bassiana, P. fluorescens, and B. thuringiensis are pathogenic to insects. Pantoea agglomerans is of interest because it produces phenols that inhibit other bacteria. To identify these organisms we have made use of Biolog, an automated system based on the development of a color pattern that develops when substrates are metabolized. The color pattern is matched to a computer database. Routine laboratory identifications, however, may depend on new DNA based techniques that are fast and do not require expensive equipment or extensive knowledge of microbial biochemistry and physiology.