Which neuropteran larvae live underwater?

While most neuropteran larvae are terrestrial and carnivorous, the larvae of the family Sisyridae—commonly known as spongillaflies or sponge flies—are aquatic.12

These larvae live as parasites on freshwater sponges. Females typically deposit their eggs on surfaces near or over the water, and upon hatching, the larvae enter the water to locate and feed on their sponge hosts. Once the larvae reach maturity, they leave the water to spin a double-walled, lacelike cocoon in which they undergo the pupal stage.31