Abstract
Students of animal populations have recognized that an increase in population density is accomnpanied, within certain limits, by a direct decrease in progeny per femaleday. This decrease has been attributed by some workers to a reduction in fecundity while others have attributed it to preimaginal mortality. Chapman ('28, '33, '34a and '34b) stressed the importance of cannibalism in populations of Tribolium confusumi, Duval, in-ferrilng ('34a, '34b) that as a population becanlie 1nore dense consumption of immature forms increased at a great rate while egg production tended to remain constanlt. He stated ('28) that althouglh thousands of eggs may be present in t)e environment at any one time, only a few of them escape being consumed. MacLagan ('32) demonstrated, through studies with Calanidra granaria L. and T. confusumn Duval, that above a certain optimum density for egg production crowding adversely affected the rate of reproduction. He stated that Chapman's contention that the reduction was due to cannibalism was only partially correct. MacLagan and Duinn ('36) showed that as populations of Calandra oryzae L. grow there is a lowering of fecundity and fertility anid an increase in the mortality of the eggs and young larvae. Thomas Park ('33), working with T. confustm, also observed an adverse effect on egg production at densities greater than the optimum. He showed that copulations stimulated fecundity up to a point; i.e., there was a place beyond which successive recopulations were not stimulating. Copulations and cannibalism
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call