.Y)S TIIK CANAI>IAN ENTOMOI.OOIRT. 



abdominal scj^mtui iium uic tud. Although with apparently as strong 

 wings as the males, ihey are heavier bodied, especially when pregnant, and 

 fly comparatively slowly and for short distances, and their organ gives 

 much less light than that of the male, though of the same quality, greenish- 

 yellow. Hoth the male and female of this species have two small luminous 

 points on the last abdominal segment ; these points frequently present a 

 continuous faint glow when the rest of the organ is dark, but they do not 

 appear to be involved in the normal flash of the insect. 



The larva of the pyralis is a narrow, sluggish glow-worm, and emits 

 light from the ventral side of the next to the last abdomin.il segment. The 

 lower side of the thoracic segments and the edges of the abdonjinal 

 segments show the pink coloration characteristic of the thorax of the 

 imago. In walking it pushes itself along with the end of the abdomen, as 

 described below for the larval /c«//jv/7'<x///V<i; \\\q pyralis larva, however, 

 does not appear to have acquired the aquatic habits oi \.\\q penrisy/vti/iica, 

 although it may be found in company with the latter glowworm, in moist 

 earth along tiie edge of roadways and paths. 



After lUc /yra//s, the most common Lampyrid here is the Photurii 

 petifisy/viviint (leer. This insect appears a little later in the evening than 

 \he /yni/is, and may fre()uently be noticed flitting around trees and bushes 

 just after sundown. It is usually easily distinguished from the pyra/is by 

 its different mode of light-emission, and the more greenish (or bluish) 

 quality of its light. It is a much more active insect than the pyralis, with 

 longer legs and a harder covering ; both sexes are winged and e(pially 

 active. In both sexes liie luminous apparatus occupies the ventral sides 

 of the two segments of the abdomen next to the last, and apparently a 

 portion of the dorsal side also, since the light may be seen through the 

 slight gap between the elytra when the insect is viewed from above. The 

 female appears to give a slightly less intense light ; at least, in mating, one 

 insect is usually to be observed to be less brilliant than the other. The 

 males are fighters, and on several occasions, when two or more have been 

 imprisoned in a test-tube together, they have been knowi\ to kill one 

 another, the insect killed being partially dismembered and the ventral 

 portion of the thorax torn out. 



The larvic of Photuris peunsylvanica are broad, flat, sluggish glow- 

 worms, rather resembling the common wood-lice ; they carry two ^mall 

 points of light on the next to the last segment of the abdomen, and when 

 walking push themselves along with the end of the abdomen. About one- 

 third of the apparent width of the larva consists of broad, translucent, 



