The effect of some secondary metabolites on food consumption and pupal parameters of male and female Malacosoma neustria L. (Lepidoptera: Lasiocampidae) larvae

Abstract

Plants produce secondary metabolites for defense against herbivorous insects. In this study, the effects of different concentrations of quinine, nicotine, and tannic acid on food consumption and pupal parameters of the larva of a severe pest, Malacosoma neustria L. (Lepidoptera: Lasiocampidae), were investigated in 2007. Artificial diets containing 0.125%, 0.25%, and 0.5% concentrations of quinine or nicotine were prepared. In addition, diets containing 1.25%, 2.5%, and 5% tannin and a control diet without secondary metabolite were prepared. The feeding experiments revealed that the food consumption and pupal parameters of male and female larvae were different, and all parameters of female individuals were higher than those of male larvae. It has been determined that tannins cause more reductions in food consumption and pupal parameters than alkaloids in male and female individuals. We observed an increase in male larvae's pupal mass with increased concentration of nicotine to 0.5%. Nicotine did not cause a decrease in pupal parameters of larvae compared to quinine. In addition, all parameters of female individuals decreased with the addition of secondary metabolite. Although food consumption in alkaloid-containing diets was less than in the control group, there was a positive relationship between food consumption and pupal lipid and protein content. However, quinine had a more significant effect on triggering protein storage than nicotine. In diets containing tannins, more lipids were stored. A decrease was observed in the food consumption and pupal parameters of all individuals in the tannin-containing diets compared to the other diets.