ABSTRACT
Agricultural crops are threatened by insect pests as well as by weeds; both of these natural enemies cause billions of dollars of damage and can affect food supply. We have developed multiple agents and tools to curb these pests; however, the weeds and the insect pests can evolve resistance to the agents used to control. For herbicide resistance, we focus on the use of glyphosate (trademarked as Roundup) to thwart weeds. This chemical has been genetically engineered into crop pests; it worked great for few years, but then weeds evolved resistance to it. As a case study, we look closely at the evolutionary genetics of glyphosate resistance to it in morning glories. One key question is whether there is a cost of resistance; for morning glories, the answer is “it depends”. We discuss the factors that lead some insect species to have a wide diet niche and to become pests. Finally, we consider the use of biocontrol and gene drives to manage insect pests.
