Sequential sampling plan for area-wide management of Rhynchophorus ferrugineus (Olivier) in date palm plantations of Saudi Arabia

Abstract

A decision-making sampling plan was developed to initiate new and validate ongoing area-wide red palm weevil Rhynchophorus ferrugineus (Olivier) integrated pest management (IPM) programmes in date palm plantations of Saudi Arabia based on the concept of sequential sampling. Spatial distribution studies revealed that R. ferrugineus population was aggregated and followed the negative binomial series with a mean aggregation index (common K) value of 3.56. In the sampling plan developed, young date palms are inspected in a sequence in units of 100 palms (1 ha) until an accurate decision on the infestation level can be made. The plan rates infestations as low and high if d0 # 0.478n 2 7.519 and d1 $ 0.478n þ 7.519, respectively, where d0 and d1 are the cumulative maximum and minimum infested palms per ha (100 young palms) for not recommending and recommending area-wide management of R. ferrugineus, respectively, and n is the area sampled in ha. In this sampling plan, if 100 palms are inspected and eight or more infestations are detected, then area-wide R. ferrugineus IPM is required. On a 100 ha scale (10,000 palms) the plan becomes stricter and permits only 55 infestations.