During the course of a study of the energy flow through a natural population of the grasshopper Chorthippus parallelus (Zetterstedt) (Qasrawi 1966) quantitative information about various aspects of the life-history was required. Since the only site available for this work was subject to interference from other users and could not be supervised, there was no possibility of using various known techniques (e.g. Richards & Waloff 1954) for the observation of the hatching rate. Furthermore the ground was so excessively stony that it was impracticable to sample for egg pods in the field. Lacking the information which these methods should yield it was impossible to apply analytical methods such as those of Dempster (1961). A new approach to the problems of population dynamics, involving the construction of a system of mathematical models to represent the life-cycle of the organism, was therefore adopted (Read & Ashford 1968). These models, unlike those of Dempster (1961), are stochastic in the sense that they take account of chance variations from one subject to another. Their application to the grasshopper populations mentioned above and to a similar study of the spittlebug Neophilaenus lineatus (L.) is discussed. The authors believe that this system of models has potential value in many types of population study, as foreshadowed by Richards (1961). The particular advantages are first their self-consistency, and second their considerable flexibility which should permit their adaptation to a wide range of different life-history characteristics, habitat situations and sampling programmes.
No takes yet. Share an insight, caveat, or question.
Ashford et al. (1970) studied this question.