220 NEW YORK STATE MUSEUM 



which is black or yellowish ; it measures about one-sixteenth of an inch in 

 diameter, but under some favoring conditions may attain a size of one- 

 eighth of an inch ; in its original description it is given as 0.08 of an inch. 



Professor Comstock described the male scale as "black, somewhat 

 elongated when fully formed. The larval skin is covered with secretion; 

 its position is marked by a single nipple-like prominence which is between 

 the center and anterior margin of the scale. The scale of the male is 

 more abundant than that of the female." It is often oval in shape, and 

 of a smaller size than the female. It is represented at 5 in Plate XII. 



When occurring upon the bark of the twigs or leaves and in large num- 

 bers, the scales lie close to each other, frequently overlapping, and are at 

 such times difficult to distinguish without a magnifying glass: see Fig. i 

 of plate XIII. The general appearance that they present is of a grayish, 

 very slightly roughened scurfy deposit. The natural rich reddish color 

 of the limbs of the peach and apple is quite obscured when these trees 

 are thickly infested, and they then have every appearance of being 

 coated with lime or ashes. When the scales are crushed by scraping, a 

 yellowish oily liquid will appear, resulting from the crushing of the soft, 

 yellow insects beneath, and this Avill at once indicate to one who is not 

 familiar with their appearance, the existence of healthy living scales on 

 the trees. {^Circular JVo.j, 2d series, U. S. Dept. Agriculture, Washing- 

 ton, 1893.) 



As before stated, the scale is also found upon the fruit. When present 

 in large numbers, to the extent of covering the entire surface, it interferes 

 seriously with the proper development of the fruit, causes it to crack, 

 often to fall from the tree, or when it remains thereon, renders it un- 

 marketable. It is a conspicuous object from the little depression which 

 it causes (at least late in the season) and usually a well-defined purplish 

 ring with which each scale is surrounded of a diameter considerably 

 larger than that of the scale (see Figure 3 on Plate XII and Figure 2 on 

 Plate XIII). 



The Insect. 

 The male. — As previously stated, the male only becomes winged. It 

 is shown greatly enlarged in Fig. 3 of Plate XIV — its natural size being 

 indicated by the crossed lines within the circle beside it. Examined un- 

 der a high magnifying power, its wings are seen to be transparent, each 

 with two delicate veins only. It has a well-defined thorax and a rather 

 large head with two large eyes. Its body is of a light amber color with 

 dark brownish markings, and terminates in a slender " stylet " nearly as 



