SUPERFAMILY TINEOIDEA 



105 



two weeks in summer the pupal shells are thrust through the 

 cocoon walls and there emerge the daintiest of shining or 

 silvery white moths with smooth rather than with tufted 

 heads. 



These larvae seem to disturb the metabolism of their host 

 plants to a very slight extent and the only species which 

 has received any attention from economic workers is P. 

 citronella, which mines the leaves of citrus fruits and is 

 particularly abundant in India and Ceylon. It is reported 



Fig. 38. The mine of Phyllocnistis on poplar leaf. Note the "nidus' 

 at the end of the mine. 



to have been introduced into the United States on nursery 

 stock but so far has not become generally distributed. 



P. vitigenella which mines in cultivated grapes is a species 

 whose mine is particularly like a snail's track. One needs 

 to see the little yellowish larvae working away under the 

 cuticle to be persuaded that these are indeed mines. These 

 larvae usually form their pupating chambers at the leaf's 

 edge, but in large leaves they may spin under the cuticle an 

 inch or more from the border. 



P. populiella is one of the commonest of the species of 



