Technology for modifying the genotypes and phenotypes of insects and other arthropods has steadily progressed by development of more precise and powerful methods, most prominently transgenic modification. There is now almost unlimited ability to modify phenotypes to benefit human health and agriculture. Precise DNA modifications and gene drive particularly have the power to make wild-type populations less harmful in ways that could never be performed with previous transgenic approaches. This transition from primarily laboratory science to greater prominence for field applications has also necessitated a greater development of modelling, ethical considerations and regulatory oversight. The second edition of Transgenic Insects contains chapters contributed by experts in the field that cover the technology and applications that are now possible. These include an increased emphasis on acceptance issues that will be necessary for application of many technologies.