THE EUROPEAN CORN BORER AND ITS CONTROL. 55 



east than in any other direction would tend to indicate that the flight of 

 the moths is influenced by the wind to some extent. 



The habit of the moth of flying close to the ground would seem to reduce 

 the possibility of wind spread to a minimum, but future observations 

 may show other influencing factors. 



Time of Maximum Activity. 

 During the day the moths remain inactive. They may commonly be 

 found hiding on the underside of the foliage of their food plant, or in strips 

 of grassland and low weeds growing along the field borders and ditches 

 of cultivated areas. They also remain inactive during cool periods, and 

 aliso during high winds. They become active in the late afternoon, and 

 reach their greatest period of activity about dusk. 



Attraction of Moths to Trap Lights. 



On the night of August 6-7, 1918, a trap light was placed midway, and 

 50 feet distant, from two areas of sweet corn which contained hundreds of 

 first generation adults. These had recently emerged from early corn 

 and were at the period of their greatest activity. The trap light was 

 started at 8 p.m. At this time the moths were actively fljdng around 

 among the corn plants. The first moth was caught at 8.45 p.m. Observa- 

 tions were continued until 11.30 p.m., and the trap light was left burning 

 until 8 A.M. the next morning. The total catch from this trap light 

 experiment was 17 moths, of which 7 were males and 10 were females. 

 Subsequent dissection showed that all of the females were gravid. 



The trap light used in the experiment was yellow in color. Examina- 

 tion of blue arc lights along the streets in the vicinity of badly invested 

 areas failed to. show that the moths were attracted to the blue lights to 

 any greater extent than has been detailed for the yellow light. 



OVIPOSITION. 



The females of the European corn borer begin ovipositing about three 

 days after emerging from the pupa (see Tables V and XI). Oviposition 

 generally occurs during the late afternoon or early evening. 



Details of Oviposition. 



The female assumes a position on the under surface of a leaf blade, and 

 bends the end of the abdomen down, meanwhile extruding the ovipositor 

 until its tip comes in contact with the leaf blade. The tip of the ovipositor 

 is fleshy and circular. Around its periphery extends a circle of amber- 

 colored hairs. After selecting the spot on which the egg is to be deposited 

 the female stands still and vibrates the ovipositor until the spherical- 

 shaped egg appears at its tip. The egg is then quickly pushed against 

 the leaf and tamped down into place by the ovipositor, which at the same 

 time flattens it. This act changes the egg from its original spherical 



