308 INSECT ARTIZANS AND THEIR WORK 



is not the only luminous insect that is found in 

 Britain. There is another species which has no 

 folk-name, but we may call it for distinction' sake 

 the Little Glow-worm (Phosphcznus hemifterus). 

 The male is not uncommon in places, but the 

 female appears to be rare. Neither sex has wings, 

 and its light-giving powers are very feeble. 



Another species which has been occasionally 

 taken in this country, but is very plentiful in the 

 South of Europe, is the Italian Fire-fly (Luciola 

 italic a). In this species — a beetle again in spite 

 of the name — both sexes are provided with wings, 

 but the female is altogether feebler and less highly 

 developed than the male. This probably accounts 

 for the fact that the female is accounted very rare, 

 the swarms that on warm evenings in May and 

 June display their light in the air consisting almost 

 entirely of males. The feebler female, like our 

 wingless Glow-worm, keeps to the herbage near 

 the ground. The Italian Fire-fly is a little smaller 

 than our male Glow-worm. Another European 

 species of Glow-worm is known as Lampyris splendi- 

 dula. 



Eaton has timed the duration of the flashes of 

 the Italian Fire-fly's light and finds that it is 

 from a third to a fourth of a second, and that they 

 are repeated about thirty-six times in a minute. 



The strange grub-like condition of our female 

 Glow-worm appears to be accentuated in a South 

 American species known as Phengodes hieronymi. 

 The winged male is especially noticeable on account 



