Mouth parts of a horsefly. Note the flat, amber, blade-like structures (upper right) that are used like scissors to penetrate and cut the skin to produce a pool of blood. The blood is then brought into the insect via the small parallel capillary channels located on the large yellow structure. The bite of a horsefly is usually more painful than a mosquito because more extensive skin damage is created by the fly compared to the more simple puncture of the small round mouthparts of a mosquito. check

DipteraTabanidaehorseflymouthparts