Effects of Plant Diet on Detoxification Enzyme Activities of Two Grasshoppers, Melanoplus differentialis and Taeniopoda eques uri icon

abstract

  • The polyphagous grasshoppers Melanoplus differentialis and Taeniopoda eques use different foraging patterns: over time M. differentialis tends to reduce the variety of host plants it feeds on and specialize on particular plants (diet components), whereas T. eques mixes host plants to achieve a very diverse diet. We tested the hypothesis that these differing behaviors are correlated with differing patterns of detoxification enzymes. The activities of midgut, fat body, and malpighian tubule detoxification enzymes were determined in last instars of the two grasshoppers, reared for five days on single- or mixed-plant diets. Significant differences in several cytochrome P450 activities and glutathione S-transferase were evident for nymphal grasshoppers feeding on different plant diets. However, the behavioral differences between the two species could not be explained by an underlying flexibility of detoxification response in M. differentialis, but lacking in T. eques. This is the first reported evidence that detoxification enzyme activities are affected by plant diet in polyphagous orthopterans.

publication date

  • 1998
  • 1998