Induction of Detoxication Enzymes in Insects

Abstract

Most of the known enzyme systems involved in the degradation of insecticides, other xenobiotics, and hormones of insects, appear to be inducible by various dietary chemicals, both plant-based and man-made. Although the understanding of the mechanism of this phenomenon comes almost entirely from studies of higher animals, there are good reasons to believe that the insect system is similar in most respects. If so, it involves a recognition system wherein exogenous chemicals in the insect's environment can stimulate the production of the enzymes that degrade them. Evidence is presented that some plant species and some plant allelochemicals are capable of such enhancement and that this is sufficient to increase the tolerance of an insect to various insecticides. It is also suggested that induction by plant chemicals may be involved in the insect's adaptation to its plant diet. Further understanding of the phenomenon, especially in regard to the cyclic nature of the process in plants and insects, may be of value in organizing pest management programs.

Assessment of physiological sublethal effects of imidacloprid on the mirid bug Apolygus lucorum (Meyer-Dür)

“…However, before drawing a final conclusion about the capacity of imidacloprid sublethal doses to modify, i.e. to increase or decrease, the efficacy of other insecticides on pretreated bugs, other bioassays should also be conducted on the other development stages of A. lucorum which may show different responses to toxicants (Terriere 1984). In addition, factors related to increased insecticide tolerance, mainly detoxificant enzymes activity, can be mediated by host plant chemicals (Feyereisen 1999).…”

Carboxylesterases in the Metabolism and Toxicity of Pesticides

“…Again, the steady-state rate constant for OP hydrolysis is effectively negligible (Ketterman et al 1992). Whereas E4/FE4 are secreted, esta and estb are associated with the microsome, which has long been known to be involved in xenobiotic metabolism (Terriere 1984).…”

Viral infection induces different detoxification enzyme activities in insecticide-resistant and -susceptible brown planthopper <i>Nilaparvata lugens</i> strains

“…Several studies have indicated decreasing susceptibility to various insecticides, including pyrethroids, organophosphates, carbamates, and neonicotinoids, [9][10][11][12][13] which is caused largely by the induction and activation of detoxification enzymes 14) such as carboxylesterase (CE) 15) and cytochrome-P450-monooxygenase (P450) against organophosphates and carbamates, 16) glutathione S-transferase (GST) against pyrethroids, [17][18][19] and P450 against neonicotinoid insecticides.…”