234 DIVERSIONS OF A NATURALIST 



glow-worm, three inches long, is found in South America, 

 which produces a red light at each end of the body and 

 numerous points of green light on each side of it. It is 

 called the " railway-beetle " in Paraguay. 



Another family of beetles besides the Lampyrids, or 

 glow-worms, is celebrated for the brilliant luminescence 

 of some of its species. These are the click-beetles, or 

 Elaterids (see Fig. 22, C). In South America there are 

 upwards of a hundred species of this group, showing 

 various degrees of luminosity. The " Cucujos " (Pyro- 

 phorus noctilucus) of tropical America is one of the most 

 abundant and largest. It is as much as an inch and a 

 half long, and has three " lamps," or luminous organs, 

 one on each side of the body and one below the tail. 

 The light given off is extremely beautiful, and the live 

 insects are used by the women for ornament and by the 

 country-folk as lamps on nocturnal excursions. Errone- 

 ously the term " fire-fly " is applied to these beetles ; it 

 should be reserved for the little Italian Luciola, which 

 swarms, as countless thousands of dancing lights, in the 

 nights of early summer over the marsh lands of North 

 Italy. I have seen it at the end of June as far north as 

 Bonn, on the Rhine. In Australia a small true " fly " x — 

 that is to say, a two-winged fly or Dipteron like our 

 gnats, midges, and house-flies — is known, the maggot 

 of which is luminous. And in New Zealand there is 

 another of which both the maggot and the perfect insect 

 are luminous. The grub is called the New Zealand 

 glow-worm. 2 



There are grounds for believing that the luminescence 

 of some of these insects serves them not to attract one 



1 Known to entomologists as Ceroplatus mastersi. 



2 Boletophila luminosa of entomologists. 



