Agricultural implications of pesticide-induced hormesis of insects and mites.

Resurgence of pest insects and mites and secondary pest outbreaks are commonly observed following pesticide applications on agricultural commodities. Reduction of natural enemy populations is the major factor blamed for these phenomena but insect or mite hormesis is a second, often overlooked factor which may be partially responsible. A major impact of hormesis is that it often leads to the need for additional pesticide treatments and can result in a spiralling increase in the use of pesticides, a term labelled in entomological literature as the 'pesticide syndrome'.