PINE-LEAF SCALE DESCRIPTION. 257 



field, Cook comity, Illinois, who gathered them the fore part of 

 September, from pines in the yard of S. Francis, Esq., in the city 

 of Springfield, in that State. These insects pertain to the genus 

 Jlspidiotus. No species of this genus has hitherto been discov- 

 ered, infesting any tree of the pine or fir family. I infer this to 

 be different, therefore, from anything which has been as yet de- 

 scribed, and accordingly name it the Pine-leaf scale-insect, Jls- 

 pidiotus Pinifolm. In size and shape these scales bear a marked 

 resemblance to those of the Apple bark-louse {A. conchiformis) 

 described in my last year's report, except that they are not 

 curved as those are. Thus their form is like that of a muscle 

 shell (Mytilus) rather than that of an oyster. Their color more- 

 over, distinguishes them from any of the other kinds of scale- 

 insects which are known to me, it being pure white, with a small 

 pale yellow spot upon the pointed end, which spot is readily dis- 

 cerned by the naked eye. 



The leaves of the pine are three-sided or shaped like a prism, 

 and it is along one of the sides of these leaves that the scales 

 are mostly placed, a few scattering ones, however, frequently 

 being stationed on one of the other sides. In the specimens sent 

 me they are crowded as closely as they can stow themselves, end 

 frequently one scale overlaps the end of the next one. They are 

 arranged lengthwise in a row, extending the whole length of 

 the leaf, their width being just equal to that of the leaf. The 

 small end in some is towards the base, in others towards the 

 apex of the leaf. 



When examined with a magnifier, those scales which are fully 

 grown appear externally to be composed of three distinct scales, 

 representing seemingly the head, thorax and abdomen of the 

 living insect — each being of an oval form with rounded ends, 

 and overlapping each other like the tiles of a roof. The largest 

 of these three segments is of a pure white color, and of a some- 

 what waxy lustre, resembling in its appearance a small oblong 

 drop of spermaceti tallow. Numerous parallel curved lines are 

 sometimes perceptible across its surface. Overlapping the end 

 of this is a pale dull yellow scale, a third or fourth of its size, 

 and having a raised line along its middle. To this succeeds 



[Assembly, 215.] 17 



