46 WALTER N. HESS. 



During the daytime the adults are rarely found, as they 

 remain hidden underneath the leaves of low herbage, or near 

 the ground covered by grass or moss. 



Neither sex was observed feeding, so it is not known whether 

 these insects eat as adults or not, but it is probable that they do 

 since they live for two or three weeks. 



The flight of these insects begins very early in the evening, 

 considerably earlier than that of the other native luminous 

 species. Almost with the first sign of twilight they are flying 

 about, and because it is comparatively daylight the beetles 

 themselves can be distinctly seen. In fact, when they begin 

 flying, their flashes appear rather faint, due to the daylight ob- 

 scuring their brilliancy. Before total darkness sets in, the 

 flight of these insects has ceased, unless for an occasional one 

 here and there. These few stragglers, however, soon stop. 

 Among the fireflies there seems to be, to a certain extent, an 

 evening periodosity of flight. This species of fireflies flies only 

 during twilight, after which other species as Photinus consan- 

 guineus and Photurus pennsylvanica take its place. The flight 

 begins shortly after 7:30 P.M. and continues until about 8:30 

 P.M. 



In comparison with most of our luminous species of fireflies, 

 the males of this species fly very low and slowly, and emit one 

 distinct flash at each period of flashing. Females were never 

 taken in flight and it seems probable that they never fly. In- 

 stead, they climb to near the top of some projecting blade of 

 grass, or some similar object, and apparently remain quiet until 

 a male comes near. Like the male, the female emits only one 

 flash, but it is much less distinct. 



There can be little doubt but that the light-emissions among 

 these insects serve as definite signals between the sexes, by 

 which means the male is able to find the female of his species. 

 Numerous observations confirming this were made, which can 

 be well illustrated by the following example : on the evening of 

 June 30, 1916, a male Photinus scintillans was observed flying 

 about two feet above the ground, and a second after he flashed 

 a female that was almost underneath him flashed. He appeared 

 to drop directly to the ground, but his velocity of flight carried 



