INSECTS INJURIOUS TO THE ORANGE. 



409 



as seventy-five per cent, of the scales have been known to be 

 destroyed by it. The female fly pierces the scale and deposits 

 in it a single egg. When hatched, the larva feeds upon the 

 eggs and young of the bark-louse, and later upon the mother 

 also. When full grown, it is nearly one-sixth of an inch 

 long, broad, becoming narrower towards the head, of a trans- 

 parent white color tinged with blackish from the alimentary 

 canal showing through. The. larva changes to a pupa within 

 the scale, which at first is white, but soon becomes darker in 

 color; the fly, on escaping, makes its exit through a round 

 hole which it cuts in the back of the scale. 



No. 261. The Hemispherical Scale. 



Lecanium hemisphcericum Targioni. 



Fig. 424 represents 

 this scale, of its natural 

 size, on orange leaves, 

 and a magnified one at 

 a. It varies in color 

 from light to dark brown, 

 and is occasionally tinged 

 with reddish when ma- 

 ture. In shape it is 

 hemispherical, with the 

 edges flattened, its form 

 varying somewhat in 

 different situations; upon 

 a rounded twig it be- 

 comes less hemispheri- 

 cal, more elongated, and 

 its flattened edges are 

 bent downwards, clasp- 

 ing the twig. 



The eggs are yellow- 

 ish white, smooth, and 

 shining. The newly- 



FIG. 424. 



