258 Wisconsin Academy of Sciences, Arts, and Letters. 
Table 1. —The Effect of Temperature on the Length of Life History of 
G. mellonella L. 
(In each case only the average number of days is given.) 
Facts Considered 
Constant Temperature 
Room Tem¬ 
perature 
(24°C.) 
29°C. 
37°C. 
Length of Egg Stage. 
25 days. 
5 days. 
7.33+ days 
35.33+ days 
8,6 days 
2.5 days 
53.76+ days 
Length of Larval Life... 
36 days. 
Length of Pupal Life.. 
5.66+ days... 
1.66+ days... 
42.33+ days.. 
Time from Emergences of Moths to Oviposi- 
tion... 
Total. 
* Larvae at room temperature hatched October 19 to 23, 1916, had not com¬ 
pleted their larval life on June 2, 1917. 
The effect of heat on the color of the moths was not especially 
marked, and there was considerable variation between individual 
moths in the same generation, but other things being equal (such 
as amount of moisture and food), the moths kept at 37° tended 
to be darker in color than those kept at 29°C. The latter were 
more often of a light tan color, while the former were dark gray 
tinged with brown. 
Effect of Light 
The larvae of Galleria mellonella respond differently to light 
stimuli at different stages in their development. When they are 
newly hatched, they seem to be neither positively nor negatively 
phototropic. For experimentation with these young larvae a 40- 
watt Mazda electric light bulb was used. When the rays of the 
bulb were directed upon the larvae which had been kept in the 
dark, they continued their wandering, making no effort to seek the 
dark. If they did happen to run out of the circle of light, they 
did not turn back into it. Sunlight also was found neither to 
repel nor to attract them. It is probable, however, that they are 
irritated by light, because they seem to move faster and in a more 
aimless fashion when exposed to light rays. 
The larvae remain thus unresponsive to light stimuli until they 
are 2 to 5 mm. in length, when they become negatively photo¬ 
tropic. On being put under a 40-watt Mazda globe they at once 
