What do adult and young lacebugs suck from plants?

Adult and young lacebugs feed on sap from plants. Their specialized mouthparts enable them to pierce the surface of leaves and extract this nutrient-rich fluid, which is essential for their development and energy. By consuming the sap, they can also inadvertently impact the plant's health, leading to symptoms like leaf discoloration and stippling, as well as possibly setting the stage for secondary infections.

The other choices present alternative feeding behaviors that do not apply to lacebugs. For instance, plant nectar is typically targeted by pollinators like bees and butterflies, while leaf tissue would imply outright consumption of the leaf material rather than just extracting fluids. Water drawn from roots is a function of plant uptake and not related to insect feeding behavior. Therefore, sap is the accurate substance associated with the feeding habits of lacebugs.