312 Annals Entomological Society of America [Vol. IV, 



in shape, but in general synonyms are used in the descriptions 

 of body shape. In the species studied, this could not be an 

 important specific character as all the species studied were of 

 practically the same shape. However, in some species, this 

 might be a distinguishing character. 



3. Color. — In descriptions the color of specimens is usually 

 given, being stated as, whitish, greyish, pinkish, with a red 

 tinge, etc. The dermis of specimens in this genus is red. The 

 color of the insect depends on the extent that this dermis is 

 hidden by the waxy secretion. The amount of waxy secretion 

 depends largely on the position in which the individual develops. 

 Those in exposed position requiring more of the waxy covering 

 as_ a protection than those developing in well protected situa- 

 tions. This variation in color is well shown in agrijoliae Essig. 

 The color in this species is usually of a reddish, pinkish, or pink- 

 ish brown. The writer has found specimens, however, ovipositing 

 in exposed positions which were completely covered with the 

 waxy secretion and through which the red dermis was not 

 visible. Thus all variations from a white to a red specimen 

 were found. In the other species studied the color was nor- 

 mally white. In the five species studied color as a character 

 for separating the species could not be relied upon. 



4. Segmentation. — In many descriptions the segmentation 

 is referred to as distinct or not distinct. This is a character 

 that is not used to any great extent. This is fortunate as the 

 value of the prominence of the segmentation as a specific 

 character is extremely doubtful. In mounted specimens it 

 would depend to a large extent upon the method used in prep- 

 aration. The segmentation in chloroform mounts is well pre- 

 served. In caustic potash mounts it would be largely oblit- 

 erated. In unmounted as well as mounted specimens the age 

 and size of the specimens is of great importance. In nymphs 

 of Pseudococcus the segmentation is very distinct. As it 

 passes through its last moult and becomes an adult, this dis- 

 tinctness of the segmentation is lost to a degree. Then as the 

 insect becomes more and more distended with eggs this ten- 

 dency to lose its prominent segmentation is increased. Also 

 the distinctness of the segmentation in unmounted specimens 

 would depend somewhat upon the amount of secretion covering 

 the insect. With these factors it does not seem that the dis- 

 tinctness of the segmentation can be a very satisfactory 

 specific character. 



