Promachus yesonicus, or shioya-abu (塩屋虻, シオヤアブ) in Japanese, is a species of robber flies.

This insect is called "shioya-abu" because the males have a white tip to their tail that resembles salt.

Male Promachus yesonicus have a white cotton-like bud at the end of their tails, while females do not.

[1] Media related to Promachus yesonicus at Wikimedia Commons

This article related to members of the fly family Asilidae is a stub.