Variability of femoral chordotonal organ reflexes in the locust, Locusts miaratoria

Abstract. The femoral chordotonal organ of a locust front, middle or hind leg was stimulated mechanically under open-loop conditions and the forces produced by the muscles moving the tibia were measured. In nearly all cases resistance reflexes were elicited in the inactive animal. However, in rare, but reproducible cases, a positive feedback occurred. In an animal performing active movements the responses were very labile: often no response occurred, sometimes a reaction comparable to the active reaction in stick insects was found, and sometimes resistance reflexes were present.