Tachypompilus ferrugineus, commonly known as the rusty spider wasp, is a species of solitary wasp belonging to the family Pompilidae. It is characterized by its reddish-brown coloration and slender body, measuring around 15-20 millimeters in length. The rusty spider wasp is known for its remarkable hunting behavior, as it preys on spiders by paralyzing them with a venomous sting and then lays its eggs on the immobilized spider, providing a fresh food source for its offspring.