GMOs – Impact on Non-target Arthropods

Genetically modified (GM) plants have been adopted at unprecedented levels since they were first commercialized in 1996. At that time, two main objectives were set by the industry: tolerance to herbicides and resistance to insect pests. While there was no promise of productivity increase, GM crops certainly reduce crop losses by reducing weed and pest populations that otherwise compete with nutrients and the overall crop ability to yield at its genetic potential. At which cost for the environment? This review focuses on non-target herbivores, pollinators, natural enemies, and detritivores. A huge body of literature reporting laboratory and field studies have been published. Although the majority of these reports show neutral or “negligible” effects of GM crops or insecticidal proteins on non-target arthropods, some reported negative effects, while a few others reported positive effects. The massive adoption of insect-resistant GM crops is accepted in cases where no other pest control method is available or else the GM crop impact on the environment will be lower than that of pesticides. However, most of the studies published to date did not compare pesticides to GM crops, in terms of potential negative impacts. There are still many unanswered questions on how GM crops might interfere with multi-trophic interactions. Even so, it is certain that we currently know better the potential effects of GM crops on non-target arthropods than those of any other crop technology developed to date.