Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/6/2011
Publication Date: 2/20/2012
Citation: Jin, X., Streett, D., Huang, Y., Ugine, T. 2012. Development of a novel bioassay system to assess the effectiveness of entomopathogenic fungi against the imported fire ants. Biocontrol Science and Technology. 22:233-241. Interpretive Summary: A novel spray apparatus was developed for testing natural pesticides. The effectiveness of the fungus, Metarhizium anisopliae strains M52 and ATCC 62176 were evaluated against imported fire ants. Two strains were virulent but the M52 strain was more effective. The results proved that this apparatus was reliable, sensitive and accurate, leading to a more efficient way to test potential naturally occuring pesticides.
Technical Abstract: Burgerjon’s spray tower has been used as a standardized method by many researchers since the 1950s. This apparatus has two chambers, one is an incline chamber connected to a vertical chamber, and compressed air is pumped into the inclined chamber by passing through water and a filter to remove the contaminants. The fine mist or dust of a biopesticide formulation is sprayed into the inclined chamber at an angle and onto the target in a vertical chamber by gravity. It can be difficult to regulate the air pressure and adjust the spray angle that drive the sprayed particles from the inclined chamber into the center of the vertical chamber. Considerable amount of sprayed formulation droplets may adhere to the wall of two chambers, so all of the sprayed particles do not hit the target insects which may affect the experimental efficacy and accuracy. A novel spray tower was developed for bioassay of biopesticide formulations. The virulence of Metarhizium anisopliae strains M52 and ATCC 62176 were evaluated against imported fire ants. Both isolates were virulent but the M52 strain was more effective against imported fire ants. Results proved that the modified apparatus was reliable, sensitive and accurate.