The Epizootiology of Nosema Pyrausta (Paillot) in The European Corn Borer, Ostrinia Nubilalis, in Central Illinois
Nosema pyrausta (Paillot), a microsporidium, is a chronic pathogen of the European corn borer, Ostrinia nubilalis (Hubner). A four year study was conducted in Woodford County, Illinois, from 1980 through 1983 in order to elaborate the relationship between corn borer density and the incidence of N. pyrausta. Factors contributing to the mortality of both generations of the corn borer are presented as partial life tables. First generation infection levels were determined primarily by the transovarial input from the first moth flight, while second generation infection levels were determined by the interaction between horizontal transmission and the first generation input of N. pyrausta. An empirical threshold for horizontal transmission was calculated for the second generation corn borers. Horizontal transmission increased when the average weekly density exceeded 50 borers per 100 corn stalks, but the initial inoculum of the pathogen also plays an important role in determining the level of N. pyrausta.
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign