Adelgidae, commonly known as adelgids, are small sap-sucking insects belonging to the order Hemiptera. They primarily feed on coniferous trees, particularly species like spruce and fir. These insects can cause significant damage to their host plants by extracting sap, which can lead to tree stress, yellowing needles, and even tree death in severe cases. Adelgids have a complex life cycle that often includes multiple generations and can involve different host plants. Some species, such as the hemlock woolly adelgid, are known for their invasive nature and have become a concern for forest health in regions like the Eastern United States. Effective management strategies are essential to control their populations and protect affected trees.