UTTAR PRADESH JOURNAL OF ZOOLOGY

Aquatic insects are found in nearly every kind of freshwater habitat and play an important role in the aquatic ecosystem as predators, parasites, shredders, grazers, filter feeders, and piercers. Due to their critical role in energy flow and cycling of nutrients, they are essential components of freshwater ecosystems. However, their survival in a particular habitat is threatened by various environmental stressors, including pollution, habitat degradation and climate change. These challenges affect their immune system, thereby weakening their natural defenses. To fight against infections, aquatic insects primarily rely on the innate immunity, which includes both humoral and cellular responses. However, environmental factors such as fluctuating temperatures, chemical pollutants, and low oxygen levels in aquatic bodies can damage these immune defenses, making the insects more susceptible to diseases. To defeat these challenges, some species have evolved adaptive strategies, both physiological and behavioural. Such changes include the production of antimicrobial peptides, improved phenoloxidase activity and the generation of heat shock proteins. In the present review, we explore the existing research on how environmental stressors impact the immunity of aquatic insects. Understanding the immunological mechanisms of aquatic insects can assist in conservation planning of aquatic insects by revealing their adaptability to environmental stressors. During our literature survey, we also examined the adaptive mechanisms the aquatic insects employ, the ecological implications of these changes and the importance of insect’s immune adaptation in conservation efforts.