On May 14, 2005, approximately 1000 mountain daylight time, a Cessna T188C , N666DB, piloted by a commercial pilot, was substantially damaged when it struck wires while maneuvering near Fowler, CO, Visual meteorological conditions prevailed at the time of the accident. The local aerial application flight was being conducted without a flight plan under the provisions of 14 CFR Part 137. The pilot was not injured. The flight originated Fowler, CO, approximately 0930. The pilot said that the accident flight was the second flight of the day. After completion of a spray run he "saw something move inside the cockpit." He glanced down, and when he returned his scan to the surroundings, he noticed transmission lines level with his aircraft. He pitched the airplane's nose up to gain altitude, and encountered a downdraft. The aircraft struck and severed three transmission wires. A utility pole was also knocked down. The aircraft was able to remain airborne and could see damage to his left wing from the cockpit. The pilot flew the airplane back to the airport and performed a wheel landing, touching down at 105 mph. He allowed the airplane to roll out the length of the runway to dissipate speed. The pilot said the outboard portion of the left wing was sheared from the leading edge to the outboard spar, and the vertical stabilizer was sheared from the leading edge to the main spar. The pilot reported wind, 130 degrees at two knots; no turbulence.