Binomial sequential classification sampling plans were developed for use in classifying populations of the English grain aphid, Sitobion avenae, below or above an intervention threshold density(mIT) for management decision making. Based on field data from sampling the aphid populations on wheat during the 1988～1991 summers, the proportion of tillers with no more than T(tally threshold) aphids(pT) was related to mean aphid density(m)with an empirical model in the form of ln[ -ln (PT)] = a+bln(m)or the negati...