High-capacity facilitative transporter for trehalose. Does not transport maltose, sucrose or lactose. Mediates the bidirectional transfer of trehalose. Responsible for the transport of trehalose synthesized in the fat body and the incorporation of trehalose into other tissues that require a carbon source, thereby regulating trehalose levels in the hemolymph (By similarity). Belongs to the major facilitator superfamily. Sugar transporter (TC 2.A.1.1) family. Trehalose transporter subfamily.