DETRITUS AS A FACTOR INFLUENCING POPULATION GROWTH RATES OF THREE TENEBRIONID BEETLES IN STORED CORN

Abstract

Experiments showed that changes in population growth rate due to detritus produced by insect activity in stored grain varies with species and is a prime factor determining ecological succession of secondary grain pests. Cynaeus angustus (LeConte), Latheticus oryzae Waterhouse, and Tribolium castaneum (Herbst) were reared on a 1:1 mixture of whole and cracked corn. On this diet, T. castaneum showed the highest rate of population growth and L. oryzae the lowest. Population growth of T. castaneum and L. oryzae was stimulated by adding fine dust (collected from infested corn) or dead moths to the diet, and this effect was much greater in L. oryzae than in T. castaneum. Population growth of C. angustus (as indicated by number of adults) was not affected by supplementation of the diet, but larger larval populations were produced on supplemented corn. The results are related to previously reported observations of succession in stored corn.