54 MASS. EXPERIMENT STATION BULLETIN 189. 



A total of 35 second generation pupae were reared from full-grown 

 second generation larvae collected in the field during May, 1918, in order 

 to secure data as to duration of the pupal period. From this material 

 35 second generation adults emerged, of which 13, or 37.3 per cent, were 

 males, and 22, or 62.7 per cent, were females (see Table X). 



Thus out of 342 second generation adults, 173, or 50.5 per cent, were 

 males, and 169, or 49.5 per cent, were females. 



It will be noted that, in the instance of the 725 adults of both genera- 

 tions represented by these figures, the sexes were present in nearly equal 

 proportions, there being 335 males and 390 females. 



Flight. 

 Character of Flight. 



Both sexes of the European corn borer adults are capable of flight. 

 They habitually fly very close to the ground, a tendency that is caused, 

 perhaps, by the fact that the plants upon which the females deposit their 

 eggs do not generally reach a height of more than 6 or 8 feet. When 

 disturbed in their hiding places during the day the adults fly close to the 

 ground, in a curious zigzag manner, for a distance of 10 or 20 feet, and 

 then seek cover again under some object. 



It is rather difiicult to observe the flight of the adults during the time 

 of their maximvun activity in the early evening. Such observations as 

 were made, however, indicated that adults normally fly very low, even 

 when seeking food plants upon which to deposit their eggs. The males 

 apparently are more active than the females, and fly for greater distances 

 and at higher altitudes. The character of their flight at this time is 

 similar to that which has been described in the instance of moths dis- 

 turbed from their hiding places during the day. 



Distances of Flight. 

 Under most conditions the moths cover a very short distance in each 

 flight, the maximum observed in any single flight being about 50 yards. 

 The females make a series of short flights in search of food plants on which 

 to deposit their eggs, so that the total distance covered by a female in a 

 series of flights may be considerable. The males make a similar series of 

 flights in their search for the females. 



Effect of Wind on Flight of Moths. 



It is not believed that the moths are carried any considerable distances 

 by the wind, although the general direction in which the insect has spread, 

 since its introduction into Massachusetts, has been with the prevailing 

 winds. 



Meteorological records show that the^e winds during May, June, 

 July and August are from the south and the southwest. The fact 

 that the insect has spread more rapidly toward the north and the north- 



