Dynamic Action Threshold Levels for the Potato Leafhopper (Homoptera: Cicadellidae) on Potatoes in Wisconsin

Publisher Website
Google Scholar
Abstract
Experiments were conducted in 1980 and 1981 at Arlington and Hancock, Wis., to develop action threshold levels (ATL) for Empoasca fabae (Harris) on potatoes in Wisconsin. Various levels of adult and nymphal densities were achieved with different treatments of fenvalerate, and subsequent effects on yield were determined. In 1980, when adults migrated into the state in relatively small numbers, the appropriate ATL was 25 adults per 25 sweeps when nymphal densities exceeded ca. 20 per 25 leaves. In 1981, adults entered the state in large numbers and the appropriate ATL was 100 adults per 25 sweeps when nymphal populations were ≤10 per 25 leaves. A dynamic action threshold model was developed by regressing the maximum number of adults attained without causing significant yield reductions in 1980 and 1981 against the nymphal population at various adult densities. This model describes a population of adults and nymphs with a single value, and is dependent on the age structure of the potato leafhopper population. The age structure is, in turn, largely determined by the size of influxes of adults.

This publication has 1 reference indexed in Scilit: