Which insect is characterized by sponging mouthparts?

Insects characterized by sponging mouthparts primarily consume liquids, as these mouthparts are adapted to suck up fluids. Fruit flies, belonging to the family Drosophilidae, possess these specialized mouthparts that enable them to soak up decaying organic matter, fruit juices, and other liquid substances. This feeding mechanism is particularly effective for their diet, which consists largely of fermenting fruits and other sugary materials.

Grasshoppers, in contrast, have chewing mouthparts that allow them to feed on plant material, while fleas possess piercing-sucking mouthparts tailored for blood feeding. Bed bugs also have piercing-sucking mouthparts but are more specifically adapted for feeding on blood from their hosts. Therefore, the distinct sponging mouthparts of fruit flies make them the correct answer in this context.