SUPERFAMILY GELECHOIDEA 



159 



leaf surfaces by consuming the parenchyma. The mined leaf 

 becomes more or less distorted. Only the older tobacco leaves 

 are affected, unless the infestation is very severe; and in these 

 grayish, irregular blotches are produced, which later turn brown 

 and become fragile, so that the tobacco is unfit for wrappers. 



The egg is pale, translucent, yellowish gray, and strongly irides- 

 cent; it is oval, 0.45 mm. long, 0.35 mm. broad at the middle, 

 membranous, and without apparent sculpture. The side upon 

 which it is deposited is slightly flattened. Eggs are deposited 

 singly upon the foliage of the host plant. Moths begin to ovi- 

 posit two or three days after emergence and continue ovipositing 

 for several nights. The largest number of eggs obtained from a 



Fig. 49. The tobacco "split-worm" Phthorimea operculella. a, larva; 

 6, adult moth; c, pupa. 



single moth was 46, but this probably does not represent the 

 maximum oviposition under normal conditions. 



The full-grown larva is 7 to 14 mm. long. The head shield is 

 0.80 to 0.86 mm. broad and fuscous brown. The cervical shield is 

 darker brownish fuscous, with a pale mid-dorsal line, shining, the 

 posterior margin medially straight. The anal shield is brown. 

 The mesothorax and metathorax are deep maroon. The body 

 varies in color through green and gray and is overlaid dorsally 

 with purplish as the larva nears pupation. The larva is very 

 active, is capable of prolonged exertion immediately after hatch- 

 ing, and clings very tenaciously to the foliage. The frass is either 

 stored in a particular part of the mine or is cast outside. The 



