Author
|
Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings Publication Acceptance Date: 1/30/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Use of chemicals to control insect pests contaminates food products such as sunflower seed and sunflower oil. Efforts are underway by the scientific community to replace chemicals by using natural enemies and diseases as agents of insect control. This study examined the pathogenicity to a sunflower insect of two types of mold. The insects were contaminated with the mold reproductive cells to see if the molds would grow and kill the sunflower pest. The results of the study indicated that the mold varieties were pathogenic, but effective control would probably be attained only if very high concentrations of reproductive cells were used. Technical Abstract: Use of chemicals to control the sunflower stem weevil Cylindrocopturus adspersus may reduce the quality of seed and oil and may be harmful to consumers and wildlife. Alternative methods of control, particularly biological control, are under development by private industry, research institutions and the USDA. The purpose of this study was to investigate the pathogenicity of two entomopathogenic fungi, Metarhizium anisopliae and Beauveria naturalis, to 5th instar C. adspersus. Insect larvae were treated by immersing 5th instar for 5-10 seconds in a test solution containing 10E7, 10E6, 10E5, or 0 (control) conidia/ml. Both of these entomopathogenic fungi were pathogenic to the stem weevil, but only the 10E7/ml concentration of conidia resulted in 100% mortality. The need for a high concentration of conidia and the life habit of the larval stages of this insect may be obstacles for effective use of these fungi as control agents for this insect pest. |
