3 SENSITIVE ACTOGRAPHS FOR COCKROACHES

Three sensitive actographs were constructed for monitroing the activit ies of cockroaches. Type 1 was a floating-tire type consisting of a ha nging circular corridor. The locomotion of the insect was detected by an infrared beam. Type 2 was a vibration type having a circular floor of aluminum foil as the track. The floor vibration was picked up by a small speaker. Type 3 was a new running wheel ty pe having six photoin terrupters to detect slight rotation of the wheel. The signals from th ese devices were analyzed automatically and quantitatively by personal computer. Each actograph gave satisfactory recordings of the activiti es of normal and operated (or decapitated) cockroaches. Type 1 had the highest sensitivity of the three types, but the results were sometime s noisy. Type 2 could record locomotive activity without positive feed back caused by movement of the apparatus. Type 3 had the highest S/N r atio. It could collect quantitative data for comparing the activities of normal and operated cockroaches.