ISSN: 2379-1764
Maria Otilia Carvalho
This short communication intends to present some references on development and validation of sequential sampling plans to estimate pest density or classifying infestation levels with reference to an action/economic threshold for integrated pest management on stored products. Sequential sampling plans were developed and validated for Cryptolestes ferrugineus (Stephens), Prostephanus truncatus (Horn), Sitophilus zeamais Motschulsky, S. oryzae (L.) and Lasioderma serricorne (F.) infesting stored wheat, maize, rice, pet food or tobacco. The methods used were Wald’s sequential probability ratio test (SPRT), Green’s fixed precision sampling, fixed binomial sampling plan and/or Iwao’s confidence interval method. The firsts experiments, data were obtained from product samples but since 2003 the absolute samples were replaced by records obtained from traps (baited with pheromone or/and food lure). Only one Tobacco Company used economic thresholds, the other industries or the storekeepers applied an empirical action threshold (AT). Some studies considered that further work is needed to improve the management decision support. Other studies gave information about accuracy of the sampling program, helped the managers to make decisions and reduce the infestation levels to values far below injury.