16 
F\ C. Agricultural Experiment Station 
“There are five pairs of spines on the ventral surface of the segment, 
and six on the dorsal. Those at the base of the median lobes are very 
small; the others are conspicuous. The second and third spines of each 
surface are situated just later ad of the second and third lobes respec¬ 
tively; in each case the dorsal spine is slightly mesad of that on the 
ventral surface. The fourth spine of the ventral surface is on the 
penultimate lobe of the thickened lateral margin. The fifth spine of 
this surface is near the anterior end of the thickened part of that mar¬ 
gin. The fourth and fifth spines of the dorsal surface are in each case 
mesad of the corresponding spines of the ventral surface. There is also 
a spine on the dorsal side, very near the penultimate segment. 
“The scale of the female is very dark gray, agreeing in color with the 
bark to which it is attached; the protuberance indicating the position 
of the exuviae is marked with a white dot and concentric ring (Fig. 9) ; 
in rubbed specimens this protuberance is smooth and black, in all cases 
the remainder of the surface of the scale is rough. The scale is very 
convex; the exuviae are usually between the center and one side. The 
ventral scale is well developed, especially at the margin, where it is much 
thickened and is dark colored; the central part is white and adheres to 
the bark, while the thickened margin is easily removed as a ring. 
Diameter of scale, 1.5 mm. (.06 inch).” (Comstock.) 
DESCRIPTION OF MALE STAGES 
First stage. The scale covering is similar to the adult male scale cover¬ 
ing and measures 1.0 mm. (% 5 in.) in length by .750 mm. (% 2 in.) in 
width. The insect is more elongate than that of the female (Fig. 5) 
and measures about .325 mm. in width and .451 mm. in length; other- 
wisewise it is similar to the female second stage. 
Fig. 10. Pupa of gloomy scale. 
The pro-pupa (Fig. 5) measures about .577 mm. in length and about 
.420 mm. in width. The color is strong chitin yellow. The general 
