LIGHTNING-BUGS. 53 



In the diurnal Lucidota, often seen flying in shady places, 

 and to be remembered by the peculiar, disagreeable, milky 

 fluid they exude when caught, the luminous organs are 

 feebly developed. In the female they are indicated by 

 yellow spots found on the last ventral segment, and on the 

 tast two in the male. In the genus Pyropyya the light 

 organs are inconspicuous, except in one species, luteicollis. 

 In Pyractomena, an attractive genus, this peculiar feature is 

 well developed in both sexes, and the light vivid at times. 

 The phosphorescent organs are larger in the male, and situated 

 on the fifth and sixth ventral segments. Close examination 

 will show in the male a large, stigma-like pore on each side, 

 midway between the middle and the side, whose office is not 

 perfectly understood. In the female the lanterns are at the 

 sides of the segments. P. lucifera, found from Massachusetts 

 to Texas, has extremely small luminous organs. 



In the genus Photinus, certain species of which have parts 

 of a roseate tint, the light-emitting organs are larger in the 

 male than in the female, and vary considerably in position in 

 the different species. In the male they cover the entire 

 ventral segments, from the fourth to fifth inclusive; and on 

 the fifth and sixth segments the little impressions or pores 

 referred to are seen in the females. The light-organs occupy 

 the middle portion of the ventral segments, and resemble a 

 flat elevation upon the fifth segment. There are so many 

 exceptions and differences, that the young naturalist will find 

 it a particularly interesting study. Thus in P. dimissus the 

 male has the usual illuminating apparatus, while it is entirely 

 wanting in the female. 



In the group Lampyres the lights are bright in the females, 

 but variable in the males. For a long time only the male of 



