BODY TEMPERATURE AND SINGING IN THE KATYDID, NEOCONOCEPHALUS ROBUSTUS (ORTHOPTERA, TETTIGONIIDAE)

¹ Department of Physiology and Biophysics, University of Illinois, Urbana, Illinois 61801, Department of Biology, Case-Western Reserve University, Cleveland, Ohio 44106 and Marine Biological Laboratory, Woods Hole, Massachusetts 02543

1. The katydid, Neoconocephalus robustus, produces a continuous song by rubbing its forewings together at frequencies of 150-200 per second. During singing the thoracic temperature is 5-15° C higher that that of the environment, the temperature gradient being greater the lower the ambient temperature.

2. Singing is preceded by a warm-up period during which normally antagonistic forewing muscles contract synchronously. The result is heat production and a rising thoracic temperature (1.5° C/min) with little overt movement.

3. The thoracic temperature at the onset of singing averages 33.5° C at ambient temperatures at 23.5°-29° C.

4. The rate of heat loss at the cessation of singing indicates that the animal must produce 0.5 cal/min (3.6 cal/min/g thorax weight) to maintain a 15° C temperature gradient.

5. This insect is immobilized by cooling to 11° C, but regains mobility when rewarmed to 21.5° C. It is reversibly immobilized at thoracic temperatures above 43.9° C.

6. N. robustus basks readily, but moves to shade at body temperatures of 37.6° C. Shuttling between sunlight and shade would permit this insect to regulate its body temperature to a high but restricted temperature range during daylight hours.

This article has been cited by other articles:

				C. Bartholomew and T. Casey Endothermy during terrestrial activity in large beetles Science, March 4, 1977; 195(4281): 882 - 883. [Abstract] [PDF]

				B. Heinrich Thermoregulation in Endothermic Insects Science, August 30, 1974; 185(4153): 747 - 756. [Abstract] [PDF]