BIOLOGY OF SOME COMMON LAMPYRID^E. 67 



The extent of the pupal period was found to vary from sixteen 

 to eighteen days under outdoor conditions. 



From the fifth of June to about the first of July the pupae may 

 be found transforming to adults within their pupal-cells. On the 

 first or second night, after transformation, the adult ruptures 

 the pupal-cell and comes forth as a mature insect. 



The larval light-organs which are functional during the pupal 

 stage continue to glow until the end of the second day of adult 

 life, when they become fainter and fainter and cease to function. 



One species that was reared did not show evidence of the adult 

 organ until after emergence, and then only in the sixth abdominal 

 segment, although the organ in segment seven began to glow a 

 few hours later. 



Since the adult light-organs are functional at the time of 

 emergence and since the larval light-organs function for a period 

 of about two days of adult life, there is a brief period during which 

 both organs are luminous (Fig. 17). 



Pyropyga fenesiralis Mels. 



This beetle is elongate, oval and slender. It is entirely black 

 or blackish except for the large pinkish subtriangular space on 

 each side of the black central disc of the prothorax. The head 

 is completely covered by the prothorax. The eyes are small in 

 both sexes. The antennae are eleven-segmented and slender. 

 The elytra are costate. The sexes are similar except that the 

 female is considerably larger than the male, and her abdomen 

 which is usually distended extends beyond the elytra. The 

 length varies from 6.5 to 10 mm. 



LeConte reports these insects from Pennsylvania, Lake 

 Superior Region, Colorado and California. Blatchley found 

 them plentiful in Indiana. 



The adults of these fireflies differ from those of the species 

 previously referred to in this paper, in that they are active only 

 during the daytime and not at night. This change in habit can 

 probably be accounted for by the absence of light-organs in the 

 adults. With this one exception, their general habits are 

 similar to those of the other species studied. They are never 

 found in dry localities, being chiefly found in low meadows along 

 streams or marshy areas. 



