Editorial overview: Pests and resistance: Resistance to pesticides in arthropod crop pests and disease vectors: mechanisms, models and tools

Arthropod pests are a profound threat to agricultural production and the health of humans and domestic animals. Worldwide, herbivorous insects and mites cause an estimated 18–20% of crop yield loss per annum representing a value of more than US$470 billion [1]. In turn arthropod-vectored diseases account for more than 17% of all infectious diseases, causing more than 700 000 deaths annually [2]. The control of these damaging pests has for many years relied heavily on the use of synthetic pesticides, and the impact of chemistry-based interventions has in many cases been spectacularly successful. For example, between 2000 and 2015 the number of deaths due to malaria halved, 80% of which was attributed to the scale-up of insecticide-based vector control interventions [3]. Unfortunately, the over-reliance on chemical pesticides has led to the emergence of widespread resistance, posing a serious threat to the sustainable control of a large number of insect pests. To effectively address this growing problem, it is necessary to understand the origin, spread and maintenance of resistance, and the underpinning mechanisms involved. The Pests and Resistance section published last year (2017) explored the ecological and evolutionary drivers of pesticide resistance, and how such knowledge can be used to inform Insect Resistance Management (IRM) and Integrated Pest Management Strategies (IPM) [4]. This current section focuses on the mechanisms that underpin resistance. An important component of effective IRM/IPM is integrating knowledge on the molecular mechanisms that cause resistance into programmes that prevent, delay, or overcome resistance. For example, once specific resistance-associated genes or mutations are identified and validated, molecular diagnostics can be developed and used to monitor the distribution and frequency of these resistance alleles in the field. Such data can then be used to inform IPM and IRM strategies than aim to slow the further development of resistance mediated by these mechanisms.