An Experimental Demonstration of Ecological Succession in an Insect Population Breeding in Stored Wheat

Abstract

Ecological suc-cession, in terms of the sequential dominance of the three species, was demonstrated over a period of 8 years in a population of the beetles Sitophilus granarius (L.) (Curculionidae), Ptinus tectus Boield. (Ptinidae) and Attagenus pellio L. (Dermestidae) breeding in English wheat. Changes in the composition of the population and in the condition of the grain, which was contained in two glass tanks, were estimated by examination of samples taken from the tanks once every four weeks and subsequently returned to their original sites. As was expected, dominance by Sitophilus granarius was followed, as soon as all whole grain had been destroyed, by dominance by Ptinus tectus which, in turn, was succeeded by Attagenus pellio. This succession is compared with other examples in animal com-munities taken from published work.