Halters

a pair of club-shaped or flask-shaped organs in dipterous insects and male stylops that are the modified posterior or anterior wings. The halters are situated on the metathorax in dipterans and on the mesothorax in stylops. The base and head of the halters are equipped with a large number of sensory organs, or sensillae, which are particularly numerous in insects that fly well. When the halters are severed or immobilized, the insects lose their ability to fly or coordinate their movements.