18 BULLETIN 1032, V. S. DEPAETMENT OF AGKICULTURE. 



hundred feet in one flight, and it is thus that bogs neighboring badly 

 infested ones, especially to the leeward, may become badly infested 

 in a few seasons. 



Other ways in which the fireworm is disseminated over a bog have 

 been mentioned, namely, in the egg state, on leaves floating over the 

 bog in the winter water (p. 7-8) , and also on cuttings (p. 4—5) . 



Proportiox of Sexes. 



In 1918, of 158 moths of the first generation emerging in the in- 

 sectary, 81, or 51 per cent, were males, and 77, or 49 per cent, were 

 females; of 59 moths of the second generation, 24, or 41 per cent, 

 were males, and 35, or 59 per cent, were females. In 1919, of 101 

 moths of the first generation emerging in the insectary 53, or about 

 52 per cent, were males, and 48, or about 48 per cent, were females ; 

 of 52 moths of the second generation 24, or 46 per cent, were males, 

 and 28, or 54 per cent, were females. This shows a slight predomi- 

 nance of males over females in the first generation and the opposite 

 in the second generation. 



Copulation. 



Copulation usually occurs shortly after emergence. Of those pairs 

 observed in the rearing shelter, one was found copulating the same 

 day it emerged, two the day after emergence, and one pair did not 

 copulate until 7 days after emergence. The same pair was never 

 seen to copulate more than once. 



The period of copulation varies in length, the minimum period 

 observed being 1 hour and 26 minutes and the maximum 26 hours and 

 65 minutes. The male of one pair observed was noted dead and still 

 attached to the female 3 days after copulation was first observed. 



OVIPOSITION. 



Egg-laying commences shortly after copulation, usually within a 

 few days. During oviposition the female rather quickly pushes the 

 egg out through the tip of the abdomen, which she holds very close 

 to the underside of the leaf. Here the egg, a soft, plastic drop, settles 

 over the surface and soon assumes its ordinary flat, oval shape. The 

 outermost covering, which is rather moist when the egg is first laid, 

 dries and cements the egg to the leaf and gives it its appearance of 

 being glued on. (See fig. 1, a.) 



Time of Day When Oviposition Occurs. 



Eggs may be laid at almost any hour of the day and evening when 

 the weather is warm and fair. However, in order to determine the 

 time of day when the moths were depositing eggs in largest numbers, 



