Appendix. 



501 



small, round, slightly elongated nipple, arising from a depressed surface ; 

 sometimes this point is brown or black, at others yellow in colour. 



The female scale is circular and varies in diameter from -^-^ to J 

 inch. The cast skins of the larva are central, the fully-formed scale 

 is mottled gTey, except over the central exuviae, where the colour varies 

 from pale to reddish-yellow, but in some it is dark brown. The scale is 

 usually smooth but sometimes slightly annulated. 



The male scale is oblong, nearly twice as long as wide, from ^j^j to ^V 

 inch long ; there is a nipple-like prominence between the centre and 

 the anterior margin of the scale. The male scale is darker than the 

 female, sometimes almost black, but the larval scale covering the exuviaj 

 is often light yellow as in the female. 

 Often the central larval scale is black 

 and the additions grey. The imme- 

 diate coverings are dull yellowish- 

 grey. 



These scales congregate thickly 

 on the bark, overlapping one another, 

 and are often covered with a black 

 sooty fungus (Fumago salicina). The 

 scales being so minute single speci- 

 mens may easily escape detection, 

 but when present in numbers the 

 grey colour shows up on the bark 

 clearly. " Trees seriously infested," 

 Mr. Fletcher* says, "look as if 

 dusted with lime or ashes." It is 

 found at the end of the branches 

 and twigs in the pear, but on peach 

 it attacks the older parts as well. 

 Upon young growths the scale is 

 surrounded by a narrow reddish 

 band, especially around the female 

 scale. On young twigs. Hunter 

 notices that the layer of tissue be- 

 tween the outer bark and wood proper becomes dark red or purplish, the 

 rings often being most striking. 



On the leaves the scales are found in one or more rows upon the 

 upper side of the mid rib. Infested leaves turn purplish-brown. 



The fruit is frequently attacked and becomes rough and pitted. On 

 pears we may always detect this scale by the reddish discoloration round 

 the scale. 



* Twenty-fifth Annual Rept. Ento. Society of Ontario, p. 74 (1894). 



[E. P. Felt. 

 FIG. 325.— SAN JOSE SCALE. (X 5.) 



