Apr. 38, 1933 
Stvdies on the Temperature oflndividual Insects 
279 
in the body temperature from about -15° to about -1°. When the 
temperature of the body began to fall the insect died when the low 
point (-15° C.) was reached the second time. 
Bachmetjew {2) made a general study of insect temperature in which 
he covered the work previously done on this subject. 
Brunnich (j) made a study of the temperature of the bee body and 
the bee brood. He used a thermocouple made by soldering a copper 
and platinum wire together, forming the warm junction of the couple. 
To the free end of the platinum wire, which was only a few centimeters 
in length, he soldered another copper wire. This second union acted as 
the cold junction of the couple. He used the room temperature for his 
cold junction and made no allowance for changes in the temperature 
of the room. He also used a telescope reading galvanometer which he 
stated was not sensitive enough, since 15 seconds were required before 
the maximum reading was reached. The bees were greatly weakened 
by piercing with this rough thermocouple and soon died. He found 
that the body temperature of adult workers went as high as 39.6^^ C., 
while that of the drones went as high as 48.4®. The results, however, 
gave no indication of uniformity, because some individuals gave high 
temperatures while others, under the same conditions, gave low 
temperatures. 
Since platinum is a good conductor of heat, there is great danger in 
having the warm and cold junction separated by a piece of wire only 
a few centimeters in length. In piercing the bee the temperature of 
its body or the handling of the wires, if held near the second couple, is 
likely to increase the temperature of that couple, thereby introducing 
an error in the readings. The increasing of the temperature of the sec¬ 
ond couple was undoubtedly the cause of the wide range in the body 
temperature cited by Brunnich in his paper. 
METHODS 
The piercing of the bees in the following experiment was done with a 
thermocouple (PI. I, A), made by soldering No. 20 double cotton 
covered copper and Constantin (a copper-nickel alloy) wire together. 
The wires were tapered to a fine point before soldering by inserting the 
ends in concentrated nitric acid and slowly withdrawing them. This 
process was repeated until the wires obtained the desired points. The 
tapered ends were then soldered together and the surplus solder filed 
off. A piece of cork was inserted between the two wires near their 
junction to strengthen the couple and aid in the handling of it. 
The readings were made with the aid of a pyrovolter (PI. I, C) and 
galvanometer (PI. I, D), and the bee was pierced with a thermocouple 
of which the cold junction (PI. I, B) was placed in a thermos bottle 
filled with ice and water to keep it at o® C. A Northrup pyrovolter 
which has scales graduated into millivolts and degrees centigrade and 
a Leeds-Northrup outside galvanometer to aid in the setting of the zero 
point were used. By having one junction of the thermocouple in ice 
and water the resulting reading on the pyrovolter was the actual tempera¬ 
ture of the bee in degnees centigrade. 
One of the rooms in a cold-storage plant was used for the low tempera¬ 
ture of 2.5°, 5.5°, 8®, and 9° C. For “room temperature,” readings 
were made in the laboratory. Temperature readings for 27^^, 30.5'^, 
35°» 39-5^» 43-5°) 52°, and 58° C. were made in a temperature box in 
