THE EUROPEAN CORN BORER AND ITS CONTROL. 51 



creamy white throughout. The cremaster and its spines, and also the 

 chitinous braces arising from the last segment, are dark red. 



About one hour after pupation the transverse pink Hues gradually 

 widen and become darker in color, until the dorsum, except at the union of 

 segments, is yellowish red. At this time the venter is almost pure white, 

 but soon begins to turn pinkish yellow in the posterior half of each ab- 

 dominal segment. This color then extends to include the entire venter 

 of each abdominal segment. The terminal abdominal segment assumes 

 its permanent color at this time. As permanent coloration proceeds, the 

 dorsum of the thorax and abdomen, together with the wing pads, turn a 

 darker red, and soon assume their permanent color. In approximately 

 five or six hours after its formation the pupa is fully colored, and retains 

 this coloration until about three or four days before the emergence of the 

 moth. At this time it becomes very much darker and shows the adult 

 markings. 



HABITS OF ADULTS. 

 Emergence of the Moths. 



After loosening its appendages the emerging moth pushes off the head 

 cap of the pupal skin by exerting pressure from within, and frees itself 

 until the head and eyes are visible. Here the moth rests for a few seconds 

 before struggling completely out of the pupal skin. About two or three 

 minutes are required for the moth to entirely free itself. At this time the 

 wings of the moth are only partly developed, and are practically the size 

 of the pupal wing pads. In this condition the moth escapes from the 

 cocoon and crawls to the surface of the plant, providing pupation occurred 

 within interior tunnels. After reaching the surface the moth obtains a 

 foothold and assumes a perpendicular position. It is never found in a 

 horizontal position at tliis time. The wings then lengthen and widen 

 gradually, meanwhile being brought vertically over the body and held in 

 this position until fully expanded. After reaching their full development 

 and expansion the wings are lowered to their normal position of rest, and 

 within a few hours the moth is ready to assume its adult activities. 



Maximum adult emergence generally occurs very early in the morning, 

 and the moths seldom emerge at any other time, unless the early morning 

 hours are rather cold. In this event the moths are delayed in emerging 

 until the early forenoon, A few, however, have been observed to emerge 

 late in the afternoon. 



Copulation. 



Copulation occurs within twentj^-four hours after the sexes emerge from 

 the pupa, and at frequent intervals throughout the life of the adult, — 

 thirteen to eighteen days' average (see Tables VI and XII). Late after- 

 noon or evening, when the adults are most active, is the usual time for 

 copulation. The act is accompUshed in a similar manner to that of other 

 lepidopterous adults. 



Polygamy experiments were tried during the summer of 1918, but no 



