Effect of heavy metals on insects

Being the most dominant animal group on this planet, insects contribute to diversity, provide numerous ecological services, influence agro-economic systems, and provide various industrial resources and medico-entomological drugs. Due to increased anthropogenic activities such as metal mining, smelting, and industries that are based on metals, heavy metals are being released into the environments that are affecting various terrestrial and aquatic organisms. Insects encounter a variety of heavy metals in their ecosystem and are being negatively impacted by these toxic metals. Many pollinators such as ants, bees, wasps, and butterflies are losing their diversity due to heavy metal pollution, which is a serious threat to agriculture. Some insects, however, have adapted to this metal stress by showing various physiological and genetic adaptations. Furthermore, many insects such as dragonflies are effective bioindicators of heavy metal pollution. Owing to the toxicity of heavy metals and as they can be transferred along the food chains, many of them recently are being exploited to enhance the biocontrol programs of insect pest management. Therefore, this chapter has been envisaged to give an overview of current knowledge on interactive effects of heavy metals with insects, the most successful class of animal kingdom on earth.