1918] Baker- — Another Toxoptera Feeding on Sedge {Homoptera; Apkididce) 91 



Male. 



The males of this species appeared in the breeding cages dur- 

 ing the early part of November and remained in considerable 

 numbers until cold weather put a check to their activities. In 

 connection with these males a reference to those of muhlenhergioe 

 Davis will be of interest. Davis (I.e.) described the males of that 

 species as apterous and gave an excellent figure. Baker and Turner^ 

 in referring to the male stated their belief that the individuals were 

 intermediates. The structure of the thorax and the ocelli are well 

 shown in the figure. Males of the present species indicate that 

 this view is correct. Several specimens, evidently indicating the 

 normal condition of the male, resemble the condition met with in 

 the males of muhlenbergiop. They possess more or less of the tho- 

 racic structure of the alate form and also the head, w hile the wings 

 are entirely absent. Other specimens, however, are more distinctly 

 intermediate in nature, having small pad-like structures repre- 

 senting the wings. One specimen was obtained in which fully 

 formed wnngs were present. The entire life cycle as observed at 

 Falls Church is spent upon the sedge and the eggs are laid upon 

 these plants in the fall. The presence of alate forms in the vivipa- 

 rous generations and more particularly this peculiar intermediate 

 condition of the males would seem to indicate that this habit of 

 remaining upon the one host has not been of very long duration in 

 this species. No truly apterous males have been observed and 

 it appears from the intermediate nature of the wingless males that 

 the species has not yet developed to the condition in which truly 

 apterous males may be found. For the sake of convenience the 

 wingless males will be called apterous though they still retain 

 the muscles of flight and other related alar structures. 



Apterous male: General color deep brownish black, the abdomen 

 somewhat paler than the rest of the body, base of the femora and 

 most of the tibiae yellowish. Cornicles, anal and genital plates 

 black. 



Antennje with the following measurements: Segment III, 0.384 

 mm.; IV, 0.19^2 mm.; V, 0.192 mm.; \T (0.08 + 0.4 mm.); Segment 

 III, with 12 or 13 small circular sensoria in an uneven row. 

 Segment IV with about the same number and Segment V with 9 



>Proc. Ent. Soc. Washington, vol. 18, p. 10-14. 



