318 



Annals Entomological Society of America [Vol. IV, 



TABLE 10. Pseudococcus obsctrus Essig. 



No formula was found agreeing with the one quoted. In 

 specimen X the right antenna has nine segments and in spec- 

 imen IX the left antenna has six segments. An examination of 

 Table 1 shows that this specimen is the largest specimen studied, 

 and as it was found in an egg mass it was undoubtedly an adult. 

 Specimen I, which will be seen to be of normal size (Table 1), 

 also had the left antenna with six segments. This variation in 

 the number of segments was also noted in other specimens. 

 The formulae of the twenty antennae measured varied as much 

 as the specifically diagnostic formulae for all the species of 

 Pseudoc6ccus, as well as one formula placing the specimen in 

 the genus Phenacoccus and two formulae placing the specimens 

 in the genus Ripersia. 



From the above review it will be readily seen that the rela- 

 tive length of the segments of the antennae are valueless as 

 specific characters. Other workers as well have found this 



