35 



These observations differ in various details from the account 

 given by Emery* of a species of which he does not give the name ; 

 he asserts that the light is emitted by the female only in response 

 to the flashes of a passing male, also that the insects remain for a 

 long while together before copulation takes place. Though he never 

 observed this action, he supposed that it only occurred late at night 

 after he had been compelled to retire from watching them. The 

 mating habits of many American species of Lampyridiie, popularly 

 known as Lightning-bugs, have been investigated recently by 

 McDermott.f In these insects, as in the European Luciola, both 

 are luminous, and the light is emitted as a series of corruscating 

 flashes. Again, the male has the more brilliant light, but in these 

 insects he seems to take the initiative in searching for a mate, 

 hovering over the ground flashing his lamp, and apparently watch- 

 ing for an answering flash from the less active female concealed 

 in the grass. 



The Lightning-bugs investigated by McDermott belong mainly 

 to the genius Fhoti)iiis, of which the species are numerous, two or 

 more of them often being found on the same ground. The results 

 of this investigator's observations, assisted by a series of ingenious 

 experiments with small electric bulbs which could be operated to 

 simulate the flash of the insect, conclusively show that each species 

 has its characteristic method of exhibiting its light, and that an 

 individual of any one species will in general only reply to, or evoke 

 a reply from, a member of the opposite sex of that species. He 

 found, however, that some species would respond much more 

 readily to his artificial flashes than others, and that some would, 

 even answer the flash of a match. 



A few details of his observations on certain species may perhaps 

 be quoted : — 



Fhotinus pi/ralis. — The flash of the female is given three or four 



seconds after that of the male, and is of the same colour, but 



of longer duration and less intense. 



Females would answer in numbers to the flash of a match 



swung in an arc to simulate the flash of a male, though as a 



rule not more than one female would reply to a flashing 



male. 



A particular female would not reply to the flash of a male 



of another species [F. consanguinens) though she would to 



that of a match. 



The male could also be deceived by a bulb placed in the 



grass and flashed three to five seconds after his own flash ; 



when the bulb was flashed without the pause it was not so 



effective. 



* "Bull. Soc. Ent. Ital.," 1886, p. 406. 



t "Canad. Entom.," 1910, pp. 357-363; 1911, pp. 399-406; 1912, p. 73 

 and pp. 309-312. 



