The term 'bloodsucking fly' can be broken down into two crossword solutions: TSETSE (6 letters) and Tabanid (7 letters). TSETSE flies are a group of large biting flies native to Africa that feed on the blood of humans and other warm-blooded animals. They are known to transmit diseases such as sleeping sickness and nagana. Tabanids, also known as horseflies, are a family of large, robust flies found in many parts of the world. They are known to feed on the blood of mammals, including humans, and are known to transmit diseases such as anthrax and tularemia.