June, 1922 bionomics op alphelinus semiflavus 213 



IDENTITY AND DESCRIPTION. 



Aphelinus semiflavus was first described by Howard ('07) 

 as follows: 



Female. — Length 1.08 mm.; expanse 1.87 mm.; greatest width of 

 fore wing 0.3 mm. Antenna? short, excluding scape about the length of 

 face; pedicel long, more than three times as long as wide ; funicle joints 

 1 and 2 in length and width and each slightly less than one-third length 

 of pedicel; joint 3 two-thirds length of pedicel and about as wide as its 

 tip; club slightly swollen, ellipsoidal, and about twice the length of 

 pedicel. Eyes faintly hairy. General color black; thorax smooth, shin- 

 ing, scape and pedicel dusky, flagellum pallid, club becoming somewhat 

 dusky at tip; front and middle femora and all tibiae somewhat dusky; 

 hind femora straw yellow. Abdomen light yellow shaded around margin 

 with brownish. Wings rather short, otherwise normal. 



Male. — Length 0.85 mm.; expanse 1.58 mm.; greatest width of 

 fore wing 0.204 mm. Differs from female in having antennae nearly uni- 

 form brown, scape slightly darker, and in the proportion of third 

 funicle joint and club. Third joint cylindrical, twice as long as pedicel 

 and six times as long as broad; club one-quarter longer than third 

 funicle joint, elongate ovate in shape. 



Described from 14 male and female specimens reared by 

 C. P. Gillette, Fort Collins, Colorado, July 15, 19, 1908, from 

 Myzus persicse, and reared at Washington from the same host 

 sent in by Professor Gillette. The parasitized host turns black. 



U. S. N. M. type No. 12,931. 



DISTRIBUTION. 



Geographical. 



There are very few available records on the distribution of 

 Aphelinus semiflavus, but these seem to indicate that it is rather 

 wide for the United States, at least. Dr. Howard has kindly 

 furnished the writer with the United States Bureau of Ento- 

 mology records that he had available, which follow: 



Reared from Myzus persicae Sulz., Fort Collins, Colorado, 

 by C. P. Gillette, July 15, 1908. 



Reared from Myzus (new species) on Aguilegia, at Lafa}^- 

 ette, Ind., by J. J. Davis. 



In addition to these, Webster and Phillips ('12) have pub- 

 lished records from St. Anthony Park, Minn., and Mesilla 

 Park, N. Mex. The present work will add Ohio to the States in 

 which Aphelinus occurs. So far it has not been found about 

 Philadelphia, Pa., after a summer season of diligent search. 



