Spatial Dispersion and Sequential Sampling Plan for the Colorado Potato Beetle (Coleoptera: Chrysomelidae)

Spatial distribution of the Colorado potato beetle, Leptinotarsa decemlineata (Say), on potatoes was studied by using Iwao’s patchiness regression technique. Early larvae demonstrated a highly aggregated pattern that stabilized with the arrival of late larvae and adults. This information was used to prepare a sequential sampling plan with 20 larvae per plant as the economic threshold. At least 600 larvae were needed to detect significant differences from the critical threshold of 20 larvae per plant; up to 40 plants were needed when the infestation level was at or near the 20 larvae per plant threshold.