Development and progeny performance of Tribolium castaneum (Herbst) in brewer’s yeast and wheat (patent) flour at different population densities

Abstract

The effects of brewer's yeast and wheat patent flour on Tribolium castaneum (Herbst) life parameters at different population densities (1, 2, 5 and 10 pairs) were examined. A standard diet (95% wheat flour + 5% brewer's yeast) was used as control. The effect was examined on the duration of egg, larval and pupal stages, total development cycle, first adult emergence, eclosion period, the total number of offspring, number of offspring per female and body weight of adult offspring. For each diet type and population density, adults were allowed to feed and oviposit for 7 days before removal from diets. A longer larval stage was recorded in brewer's yeast (between 23.88 and 26.25 days, depending on population density) and patent flour (17.63–23 days) compared to the standard diet (12.88 and 13.38 days). The longest eclosion period was recorded in patent flour (19–21.23 days), which was the only diet unaffected by population density. In the brewer's yeast and standard diet, the period of eclosion was prolonged with the increase in population density. The lowest number of progeny was recorded in patent flour (44.29–49.63 insects), followed by brewer's yeast (22.86–177 insects), while the highest number of progeny (107.25–313.38 insects) was recorded in the standard diet. Population density did not affect the total number of progeny in patent flour, which remained low at all densities, while in the brewer's yeast and standard diet the rise in population densities caused a rise in progeny numbers. The type of diet did not affect the body weight of adult progeny: the highest body mass of progeny was recorded at the lowest population density and the lowest mass at the highest. This study provides insight into poorly researched development cycle and reproductive strategies of T. castaneum on brewer's yeast and patent flour, which are important stored products.