USE OF A SOUND-BASED VIBRATOME BY LEAF-CUTTING ANTS

Leaf-cutting ants harvest fresh vegetation that they then use as food for symbiotic fungi. When cutting leaf fragments, the ants produce hig h-frequency vibrations with a specialized organ located on the gaster. This stridulation behavior is synchronized with movements of the mand ible, generating complex vibrations of the mandibles. The high vibrati onal acceleration of the mandible (up to three times the gravitational force at peak acceleration at about 1000 hertz) appears to stiffen th e material to be cut. An identical effect is achieved when soft materi al is sectioned with a vibratome. This hypothesis is supported by expe riments simulating the cutting process with vibrating isolated mandibl es: When tender leaves were cut, the vibration of the mandible reduced force fluctuations and thus permitted a smoother cut to be made.