Author
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Alverson, Janet |
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Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/7/2002 Publication Date: 4/1/2003 Citation: ALVERSON, J. EFFICACY OF ANTIFUNGAL AGENTS TO CONTROL ASPERGILLUS NIGER CONTAMINATION INAN ARTIFICIAL DIET FOR LYGUS HESPERUS KNIGHT (HETEROPTERA: MIRIDAE). JOURNAL OF ENTOMOLOGICAL SCIENCE. 2003. p. 278-285. Interpretive Summary: Biologically based techniques of insect pest control have been developed as alternatives to conventional pesticides. Many of these technologies require mass rearing of insects. However, mass rearing relies on artificial insect diets that require safe, reliable means of reducing microbial contamination and spoilage. The ability of a panel of antifungal agents to control a common mold, Aspergillus niger, in an artificial diet for Lygus hesperus, the Western tarnished plant bug was tested. Benzoic acid and a high concentration of sorbic acid were found to be the most effective at controlling A. niger and also had the least toxic effects to the plant bugs. This research is of benefit to the growing insect rearing community (commercial and government-based) in establishing techniques for efficiently rearing high quality insects. Technical Abstract: The ability of four antifungal agents to suppress growth of Aspergillus niger in an artificial diet for Lygus hesperus Knight (Heteroptera: Miridae) was tested by inoculating a standard number of conidial spores into artificial diet with different antifungal agents added, and determining the amount of microbial growth. The effects on biological fitness of L. hesperus were also measured. Biological fitness characteristics measured included total number of surviving adults, mean biomass (dry weight) accumulated per cage over the total treatment period, egg production, time to adult emergence, and time to the beginning of egg laying. Benzoic acid, high concentrations of formalin, and a high concentration of sorbic acid suppressed the growth of A. niger. Propionic acid and low concentrations of sorbic acid and formalin were less effective at suppressing A. niger growth. Biological fitness was negatively affected in insects reared on diets containing high levels of A. niger growth and in diets with high concentrations of formalin. This study demonstrates how the antifungals that are added to the artificial diet of L. hesperus to control contamination by A. niger must be chosen carefully with consideration not only of their effectiveness at controlling contamination, but also to the tolerance level of the insect to the chemical compound. |
