insect immune system

Insects rely on an immune system to fight off infections from bacteria, fungi, and viruses. Their defense includes barriers like a tough outer shell called the exoskeleton and gut lining. If pathogens breach these, insects activate internal responses: cells that recognize and engulf invaders, and a set of proteins that attack and destroy microbes. Unlike humans, insects lack an adaptive immune system, so they rely on these innate defenses that provide rapid, broad protection. This system helps insects survive in diverse environments despite their simple immune structure compared to vertebrates.