406 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.51. 



shorter than segments IV, V, and VI, but usually longer than these. 

 Sexes about equal in size, the claspers of male with a few prominent 

 spines. 



Type. — Dialeurodes (Dialeurodes) citri (Ashmead). 



KEY TO SUBGENERA OP DIALEURODES. 



1. Vasiform orifice of pupa case armed with teeth on its inner caudal and lateral 



margins 2. 



Vasiform orifice of pupa case not armed with teeth on its inner caudal and lateral 

 margins 3. 



2. Pupa case with a distinct row of marginal spines; dorsal disk without a rhachis, 



but with an irregular row of pores on each side; thoracic tracheal folds distinct, 



often brightly colored Subgenus Dialeuronomada. 



Pupa case without a row of marginal spines; dorsal disk without rhachis or rows of 

 pores; thoracic tracheal folds distinct, usually covered with small circular 

 dots Subgenus Dialeurodes. 



3. Pupa case without large simple pores on dorsum 4. 



Pupa case with large simple pores on submarginal area of dorsum. 



Subgenus Dialeuropora. 



4. Pupa case without a row of marginal or submarginal spines 5. 



Pupa case with a row of marginal or submarginal spines; these often knobbed or 



vasiform; rhachis often very prominent Subgenus Rhachisphora. 



5. Pupa case witliout a row of distinct small pores; rhachis not suggested 6. 



Pupa case with a row of distinct small pores; rhachis suggested. 



Subgenus Dialeuroplata. 



6. Thoracic tracheal folds not covered with polygonal markings 7. 



Thoracic tracheal folds covered with polygonal markings, most numerous about 



the pores Subgenus Rusostigma. 



7. Thoracic tracheal folds covered with linear ridges Subgenus Rabdostigma. 



Thoracic tracheal folds not covered with Linear ridges, but usually with minute 



circular dots Subgenus Gigaleurodes. 



Subgenus Dialeurodes Cockerell. 



The first group within the genus is composed of species similar to 

 citri. Two species of the subgenus were described from America, 

 where they are orange pests of importance. The investigations of 

 Mr. Woglum in India and Ceylon have discovered in that territory 

 the presence of one of these forms, and it is considered probable that 

 the second is also indigenous to those regions. 



Pupa case elliptical, yellowish, with sometimes a median brownish 

 area; marginal wax tubes represented by irregular, shallow corruga- 

 tions on the submarginal area; vertical waxen fringe absent and case 

 usually without waxy secretion of any kind; dorsal disk without 

 sculpturing or large pores and with no development of a rhachis; 

 thoracic tracheal folds ending on or near the margin in a pore and 

 marked with minute circular dots; vasiform orifice broadly suboor- 

 date to subcircular, armed on its inner caudal and lateral margins 

 with a comb of teeth. 



Adult with forewings somewhat elongate, usually transparent, 

 without thickened veins and no sensoria present; antennae with seg- 



