420 THE COCCINA, OB COCHINEALS. 



Lacca), which not only furnishes us with the dye-stuffs 

 known as lac-dye and lac-lake, but also, by its action 

 upon the trees which it inhabits, with the resinous sub- 

 stance called shell-lac, of which so much is employed 

 in the manufacture of sealing-wax and varnishes. In 

 former days, the Lecanium Ilicis, a species infesting 

 the evergreen-oak of the countries bordering the Me- 

 diterranean, was much used for dyeing red, and the 

 Porphyrophora polonica, a species found on the roots 

 of the Scleranthus perennis, is still employed for the 

 same purpose in some parts of Central Europe. 



Although the majority of the insects of this tribe 

 have inactive females, this rule is not without its 

 exceptions; the females of a few species are active 

 throughout their existence, although still quite de- 

 stitute of wings. One of these, which may be found 

 commonly upon the nettle, is the Dorthesia Urtica, a 

 small insect, usually about a twelfth of an inch in 

 length, and entirely covered with a snow-white se- 

 cretion, which forms numerous separate little plates 

 upon its upper surface. The male is furnished with 

 a single pair of wings, and the extremity of his ab- 

 domen terminates in a long tuft of white filaments. 



Aphrophora bifasciata. 



