Premium
Extensions to Southwood and Jepson's graphical method of estimating numbers entering a stage for calculating mortality due to parasitism
Author(s) -
Bellows T. S.,
Van Driesche R. G.,
Elkinton J. S.
Publication year - 1989
Publication title -
population ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 59
eISSN - 1438-390X
pISSN - 1438-3896
DOI - 10.1007/bf02513200
Subject(s) - parasitism , graphical model , statistics , parasitoid , stage (stratigraphy) , host (biology) , mathematics , biology , ecology , paleontology
Summary Seven methods of estimating percentage parasitism using graphical estimates of host or parasitoid recruitment are presented. Biases affecting these percentage parasitism estimates arise from the effect of mortality on graphical estimates of numbers entering a stage. These biases result in underestimation of parasitism in some of the methods examined and overestimation in others. The methods and their biases are discussed and illustrated with reference to data from four generations of Pieris rapae (L.) parasitized by Cotesia glomerata (L.). The general impact of these biases are discussed with reference to situations where the methods might be applied.