The Effects of Iridoid Glycoside Plants on Manduca sexta

Abstract

The study that we conducted investigates how well Manduca sexta will survive off iridoid glycoside(IG) containing plants. We intially believed that Manduca sexta would adapt better to a diet that composed of the artificial diet. This is due to the fact that IG plants are not the usual plants that Manduca sexta consume in their diet. The pyrrolizidine alkaloid (PA) and IG chemicals are found in plants that are used for defensive purposes. M.sexta have been found to feed off of PA plants for their diet. We grouped the caterpillars into specific groups with different diets that were than observed weekly for four weeks to see the rates for growth, defecation, and amount of plant matter eaten. We found that the group of M. sexta that was fed exclusively the artificial diet did not grow nearly as much as the group fed off of the Lycopersicon esculentum and Lonicera japonica, which is an IG plant. There is statistical evidence that M. sexta have better adapted to the IG plants than the artificial diet using the ANOVA method on SPSS. This further gives evidence that M.sexta are in fact able to grow from eating IG plants, but also adapt well to the diet of IG plants.

Keywords: pyrrolizidine alkaloid, iridoid glycoside