Common European Cleg (Gadfly)
The common European Cleg is a large, black/blue-black blood-sucking ‘horsefly’ of the family Tabanidae. It is commonly referred to as a Gadfly in the United States. They are powerful flyers, and the females are furnished with a lancet-like proboscis which can pierce the thickest skin.
John H. Finley ed. Nelson's Perpetual Loose-Leaf Encyclopaedia (vol. 5) (New York, NY: Thomas Nelson and Sons, 1917)