S26 A NATURALIST IN THE GUIANAS 



use of the magnesium light was the invasion of our camp 

 by numbers of moths and other nocturnal insects, 

 of which I secured more than 100 specimens. On the 

 following morning I observed around our camp-fire 

 the singed and mutilated remains of many of these 

 moths and insects. They had evidently visited us in 

 numbers during the night and had perished miserably, 

 lured by that strange spell which a bright light casts 

 upon them. 



It is exceedingly interesting to observe what takes 

 place when a bright light is used for the first time 

 in some locality. When the electric light was installed 

 in the streets of Port of Spain, the ground under the 

 lamps used to be strewn with various kinds of insects. 

 Of a sort of giant water-bug ' in particular, such numbers 

 were destroyed that the insect came to be generally 

 known as the electric beetle. In fact, I am not quite 

 certain but that there were some people who connected 

 the establishment of the electric light with the genera- 

 tion of this bug. These bugs no longer visit the lamps 

 in numbers, so that either the species has got scarce 

 through the destruction of the greater part of its members, 

 or the survivors have learnt that visits to the lamps end 

 fatally. It may be, also, that certain individuals are 

 exempt from the fascination a bright light has for the 

 rest of the species. 



Another very curious result of electric lighting in 

 Trinidad is that the bats have learnt to make use of 

 the lights for catching moths and other insects. They 

 fly about in the vicinity of the lamps, having discovered 

 that their prey is more abundant there than elsewhere, 

 and they intercept their winged victims on their way 



' Ncpa grandis. 



