Response of stored product pest life strategy to chemical treatment : effect of tricalcium phosphate (TCP) on Tribolium strains (T.castaneum herbst and T. confusum Duval)

The experiments were carried out on two strains: cl of Tribolium castaneum (Hbst.) and bIV of T. confusum Duval. in medium enriched by yeast using tricalcium phosphate (TCP) as the controling factor. Within these two species two groups of 6- and 7- instar individuals were discerned. The developmental time and survival of T. confusum population is depressed stronger than those of T. castaneum. There are no differences between 6- and 7-instar groups in response to various concentration of TCP. The results obtained for fecundity showed that this trait is more restricted in T. castaneum than in T. confusum. Hatchability in all experiments was similar.