THE EUKOPEAN CORN BORER AND ITS CONTROL. 43 



and thoracic shield become black and are observed to occupy a central 

 position in the egg. The body segmentation and the black spines on the 

 body of the larva are also plainly discernible. At this time the develop- 

 ing larva is curled up inside the egg with its mandibles resting upon the 

 next to the last abdominal segment. These mandibles soon begin to move 

 laterally, and the larva straightens itself out in such a manner that the 

 mandibles are brought into contact with the eggshell. A slit in this is 

 soon made, and the larva crawls forth. After hatching, the larva feeds, 

 to some extent, upon the empty eggshell, but has not been observed to 

 entirely devour it. 



Habits when attacking Corn, 

 First Generation. 



The newly hatched larva crawls about over the surface of the corn 

 blade on which it hatched, stopping here and there to eat a small area 

 of the epidermis on either the upper or lower surface of the blade (see 

 Plate I, Fig. 1). These small areas are usually bordered by veins on each 

 side and are longer than wide. 



During its travels the larva gradually approaches the growing crown 

 of the plant, and, upon reaching it, descends between the rolled leaf blades, 

 or cone, composing the crown, and feeds internally upon the young and 

 succulent epidermis of the unfolding leaf blades. If the tassel is present 

 within the cone the first in star larvae may feed upon the epidermal cells 

 composing the flower buds, but only rarely do larvae of this instar enter 

 the buds. 



When ready to molt, the first instar larva spins a thin, silken molting 

 cocoon in some protected location near its last feeding place, within which 

 it molts to the second instar. 



Upon emerging from its molting cocoon this larva immediately attacks 

 the staminate flower buds if the tassel is present within the crown. If the 

 tassel is not present it feeds on the tightly rolled leaf blades composing the 

 crown in a similar manner to that described for the first instar, except 

 that larvae of the second instar are able to eat entirely through the blade, 

 and do not confine their feeding to the epidermis. When the tassel is 

 present within the crovm the second instar larva bores a hole in the side 

 of one of the staminate flower buds and feeds upon the internal succulent 

 contents. Entrance to the bud may be effected from the top, at the base 

 or from the side, several buds are destroyed in turn by each larva. Dur- 

 ing the process of feeding within the buds considerable frass is extruded, 

 and this becomes webbed together with the silk spun by the larva in 

 traveling from bud to bud, and forms a certain amount of protection for 

 the larva. This webbing together of frass for possible protection is char- 

 acteristic of the second generation larva, as, although larvae of the first 

 and later instars are capable of spinning a web, they do not use it for 

 purposes of protection while feeding. 



When ready to molt, the second instar larva spins a molting cocoon, 



