188 



FIREFLIES AND GLOW-WORMS AND 

 THEIR LIGHT. 



By K. G. Bi.AiK, li.sc. F.ivS. 



fAsSISTANT EnTOMOLO(JIST AT THE BuiTlSII MuSEUM, 



Natural History). 



There is perliai)s no more striking phenomenon in the insect 

 world, than the brilliant and frequentl}^ flashing lights exhibited at 

 night b}^ the insects popularly known as Fireflies and Glow-worms, 

 yet at lirst sight it is astonishing Jiow little is known to scientists at 

 home of the habits of these insects, and ot the part played by this 

 luminosity in their life histor3\ But when we consider that our 

 knowledge of these creatures is almost entirely based on the dried 

 specimens of our collections, which are practically never accompanied 

 by detailed or in an}" way critical notes on their habits as observed by 

 the collectors, this deficiency in our information on the subject be- 

 comes more readil}'- intelligible. 



The lack of co-operation between the systematic sfcudoit at 

 home and the actual collector in the field, whether a trained entomo- 

 logist or not, was particularly brought home to me in conversation on 

 this subject with mj' friend Mr. K. G. Gairdner on the occasion of his 

 present visit to this country'', and it is at his request that these notes 

 are written with the express purpose of interesting the members of the 

 Natural Histor}'- Society of Siam in the study of these fascinating 

 creatures, and of helping to elucidate the life histories of some of the 

 Siamese species. 



With few exceptions, luminous insects throughout the vvorld be- 

 long, broadly speaking, to one family of Beetles, the Lmnpuridac, or 

 to give them their popular name, the Fireflies and Glow-worms. The 

 most important exception to this statement is afforded by the Fire- 

 flies of the ^Vest Indies and Central America, locally known aa " Cucujos," 

 which, though still Beetles, belong to quite a different family, the 

 l^laicridae or Skipjacks. 



