Management sampling for larvae of the colorado potato beetle

Summary Untreated plot of ‘Kennebec’ and ‘Superior’ potatoes were sampled for Colorado potato beetle (CPB) at L'Assomption, Quebec, in 1982, 1986 and 1987. Numbers of CPB larvae per stalk were counted on 74 occasions for sample sizes ranging from 50 to 200 stalks. Regression techniques were used to estimate the relationship between mean and cumulative proportion of stalks infected. These were used to set up binomial sequential probability ratio test (SPRT) sampling plans for pest management decision making with tally numbers (or tally thresholds, cutoff numbers) equal to 0,1,…10. A binomial scheme defined by tally number equal to 4 is proposed for general use, and corresponding plans are given, with estimated operating characteristic and average sample number curves.