Interaction of two species of Cryptolestes (Coleoptera, Cucujidae)

Abstract

In order to seek at least a partial explanation of the differential occurrence of Cryptolestes turcicus (Grouv.) and C. ferruginous (Steph.), the interaction between different combinations of the larvae of the two species was studied when each newly hatched larva was provided with 12·5 mg. wheatfeed. It was found that the numbers of C. turcicus surviving to the adult stage in the presence of C. ferrugineus was a linear function of its own initial numbers, whereas the survival of C. ferrugineus seemed to be some function of the size of the environment. This conclusion, taken together with other data, suggests that if the two species were to gain access to cereals together, dry conditions, coarse food, low larval density and the availability of refuges for pupation would favour high populations of C. ferrugineus, whereas moist conditions, fine food, moderate to high larval density and the absence of refuges for pupation would favour high populations of C. turcicus.