|Hatting, Justin - ARC-SMALL GRAINS INST.|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: May 24, 2007
Publication Date: November 23, 2007
Citation: Hatting, J.L., Wraight, S.P. 2007. Optimizing bioassay precision, with special reference to the Aphididae and Aleyrodidae. Book Chapter. In: Ekesi, S., Maniania, N.K. editors. Use of Entomopathogenic Fungi in biological Pest Management. India:Research Signpost, Kerala. p. 197-237. Technical Abstract: A critical step toward successful development of a fungus-based biopesticide is selection of a fungal strain with superior aggressiveness toward the intended target host. This procedure is normally performed under strictly controlled laboratory conditions and generally termed biological assay or bioassay. There is no single set of methods that can be applied to the bioassay of the great diversity of fungal pathogens against the even greater diversity of target insect pests; methods vary not only with the test subjects but also with specific research objectives. Nevertheless there are a number of general procedures that can contribute to the reduction of assay-to-assay variability (increase bioassay precision). In this chapter we identify and discuss what we consider the most important of these procedures, particularly as they relate to the bioassay of fungal pathogens against aphids and whiteflies. A method for bioassay of fungi against cereal aphids is described in detail. The assay was designed to ensure accurate dose administration and quantification, accommodate maintenance of treated aphids on living host plants to encompass a broad range of experimental objectives, minimize control mortality by reducing aphid handling, and enable testing of multiple aphid species. Statistical methods for analysis of data from repeated bioassays and bioassays with numerous treatments are also reviewed.