Model for the within-plant vertical distribution of European corn borer (Lep., Pyralidae) larvae.
1991
Labatte J.M.
The European corn borer (ECB) is a major pest of corn in many countries. Yield losses due to ECB depend on the stalk tunneling data, the number and location of cavities on the corn. To describe the location of cavities due to ECB, a model of larval distribution within the plant is proposed here and tested on field data collected at INRA-Versailles, France. Comparison of changes in larval distribution on the plant for different infestation dates suggested that the stage of corn growth is the main factor to be taken into account. Statistical tests did not reveal any effect of instar nor of infestation date or rate. For a given infestation, the larval distribution changed also significantly with corn growth. The proposed model consists of two parts. We first showed that, for a given observation, Weibull density describes correctly larval vertical distribution on the different internodes of the plant with only two parameters. Then we represent the course of these parameters with corn growth by regression curves on degree days (base 6 degrees C). For the seven climatic sequences recorded, this simple model is an appropriate representation of the larval vertical distribution and movement within the plant.
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