Sampling techniques for Populations of Pine Woolly Aphid Pineus pini (Gmelin) (Homoptera)

Abstract

From observations on Pinus patula at 4 places in Kenya, procedures for sampling populations of all stages in the life history of Pineus pini (Gmel.) are given. The distribution pattern of the aphids within the tree crown branches is described, and tables are presented giving the numbers of trees to be sampled in order to estimate populations with a known precision, either by measurement of pine needle lengths or by counts of aphids present. A highly significant negative relationship between needle lengths and aphid numbers suggests that measurements of needle lengths alone are adequate to estimate the intensity of infestation.