What order includes the three-pronged bristletails?

The order that includes three-pronged bristletails is Thysanura. This group of insects is characterized by having elongated bodies and three long appendages at the rear end, which resemble tails. The name "Thysanura" itself derives from Greek words meaning "fringe" and "tail," emphasizing the distinctive feature that sets these insects apart.

Members of this order are typically wingless and are known for their ability to thrive in a variety of environments, often being found in moist habitats where they feed on organic materials. Their morphology, such as the presence of the three-pronged tail structure, is key to their classification within this specific order.

In contrast, the other orders mentioned offer different characteristics and classifications: Mallophaga includes chewing lice, Siphonaptera consists of fleas, and Collembola refers to springtails, which all have distinct forms and ecological roles that do not align with the features of Thysanura. Therefore, the identification of three-pronged bristletails as belonging to the Thysanura order is accurately reflected in the choice provided.