Notes on the Distribution ofCephus Pygmaeus, Linn., and of its Parasite,Collyria calcitrator, Gray

Abstract

The wheat crops in certain districts of England are attacked every year by the wheat-stem sawfly, which in its turn acts as host to various species of parasitic insects. The aim of the present investigation is to try to discover from an analysis of records if any sort of simple numerical relations exist within the complex including the wheat field, the sawflies which infest the wheat-stalks, and the parasites which attack the sawflies. The results of this work lead to a discussion of the peculiar difficulties involved in the application of mathematics to the study of animals and plants in their natural environments.