Vol. 57 
PSYCHE 
No. 2 
June, 1950 
THE INFLUENCE OF TEMPERATURE UPON 
THE RESPIRATION AND HEART ACTIVITY OF 
THERMOBIA AND GRYLLOBLATTA. 1 
By 
George A. Edwards (Tufts College) 
and 
Wm. L. Nutting (Harvard University) 
A recent survey of the literature concerning the metabolism- 
temperature response of insects suggested that this large and diverse 
class makes no metabolic adaptations to fluctuations in environ- 
mental temperature. Therefore, it seemed appropriate to investigate 
several specialized insects to determine if metabolic adaptations are 
made to particular temperature ranges. The initial experiments 
included representatives of two primitive orders occupying extremes 
on the temperature scale. It is hoped that these may serve as limits 
for future work of similar nature on the insects as a group. 
The firebrat, Thermobia domestica Packard (Thysanura), was 
selected as the representative of a hot environment. The firebrat 
has a well deserved name in that it is found in hot, damp places such 
as boiler rooms. It has a temperature preferendum of 32° to 44° C, 
and an optimum of 37.5° C and 60% relative humidity, at which 
level it completes the life cycle in about three months. It molts 
and continues to increase in weight throughout the whole life span 
(Adams, 1933; Sweetman, 1938; Woodland, personal communica- 
tion). 
1 The work described in this paper was done, in part, under contract 
between the Medical Division, Chemical Corps, U. S. Army and Tufts 
College. Under the terms of this contract the Chemical Corps neither 
restricts nor is responsible for the opinions or conclusions of the authors. 
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