748 Journal of Agricultural Research voi.xx.No. 10 



FIRST INSTAR 



Structural, characters. — The larva increases in length from about 

 2 mm. at hatching to about 5 mm. at the beginning of the second stage. 

 In proportion the thorax is slightly large for the abdomen, whereas the 

 head is large for the thorax. The body spines are obsolete, and the spi- 

 racles are unusually large, having the appearance of being expanded. 



Color. — The head is brownish with the eye spots, the labial and 

 maxillary chitin, and the apices of the mandibles blackish. The body 

 is unspotted and previous to feeding is entiiely yellowish gray, but upon 

 the filling of the alimentary canal it appears green or lead green. The 

 thoracic leg joints are blackish. 



SECOND INSTAR 



Structural characters. — The second stage develops in length from 

 about 5 mm. to 7.5 mm. The head is still large but the thorax and 

 abdomen are nearly normal in their relation to each other. The spiracles 

 are now about normal in their appearance, and the spines are becoming 

 fairly distinct. 



Color. — The head is brownish with the eye spots and the labial and 

 maxillary chitin blackish. The body is unspotted and pale yellow- 

 green, with the spines appearing faintly grayish, and the thoracic legs are 

 blackish. 



THIRD INSTAR 



Structural characters. — The larva in the third instar grows in 

 length from 7.5 mm. to 10 mm. The head is still large, wider and higher 

 than the thorax, and the body spines are now prominent. 



Color. — The head is brownish to brownish black, with the eye spots 

 black but not conspicuous. The lab rum, apices of mandibles, and chitin 

 of the labium and maxillae are brownish black. The thorax and abdo- 

 men are pale, usually unspotted, but in some larvae with very faint gray 

 supraspiracular spots and epiproct. The thoracic leg joints are black. 



FOURTH INSTAR 



Structural characters. — The larvae of the fourth stage lengthen from 

 10 mm. to 12.5 mm. The head is now about normal size in relation to 

 the body. 



Color. — Approximately the same as in the sixth stage. The head 

 varies from brownish to orange and the body is normally spotted with 

 gray black. 



FTFTH INSTAR 



Structural characters. — The fifth stage increases in length from 

 14 mm. to 18 mm. Structure as in sixth stage. 



Color. — Same as the sixth stage except that the head sometimes has 

 more brown and the body markings appear in some instances propor- 

 tionally larger and a deeper black than in the sixth stage. 



