Dietary effects of secondary plant compounds on nymphs of Melanoplus sanguinipes (Orthoptera: Acrididae)

The effects of some secondary plant compounds in a 5-d bioassay on the survival and mean weight of surviving nymphs of the migratory grasshopper, Melanoplus sanguinipes (F.), are described. In total, 22 secondary plant compounds were individually added to the dry diet in six concentrations. No significant treatment effects were observed with harmalol, harmol, quercetin, or with caffeic, p -coumaric, ferulic, gentisic, or syringic acids. Both naringenin and rutin significantly affected mean weight but not survival. Saponin significantly decreased survival. Oleanolic and chlorogenic acids and sparteine significantly decreased mean weight. Vanillic acid significantly increased mean weight. Gramine, harmaline, harmane, harmine, hordenine, scopoletin, and flavone significantly decreased survival and mean weight.