Vol. 30, pp. 77-78 March 31, 1917 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



A NEW APHIS-FEEDING APHELINUS. 

 BY L. O. HOWARD. 



Until last summer only four species of Aphelinus have been 

 reared from plant-lice by the men in the Bureau of Entomology 

 in 35 years. It is therefore interesting to add a fifth species. 



Aphelinus lapisligni n. sp. 



Female. — Length, 1.05 mm.; expanse, 2.19 mm.; greatest width of 

 l'orewing, 0.57 mm. A medium sized black species. Eyes faintly hairy, 

 but with well bristled margins. Antennae rather short, stout, of the A. 

 nigritus rather than the A. semiflavus type. Third funicle joint \% times 

 longer than broad ; club 2% times longer than broad. Base of forewing 

 singularly free from bristles ; aside from the more or less irregular row 

 proximally bordering the oblique hairless streak, there are seen but six 

 or seven of these bristles in the distal angle between the marginal vein 

 and the hairless streak. Body uniformly glistening black ; wings infus- 

 cated below marginal vein ; forelegs with basal two-thirds of femora 

 black ; apical third whitish yellow ; tibiae whitish yellow ; tarsi dusky 

 towards tip ; middle femora and tibiae black, light at tips, trochanters 

 yellowish, femora enlarged; hind legs same. Antennae yellowish white, 

 club darker towards tip. 



Type, U. S. N. M., 21,126. 



Numerous specimens reared from Aphis bakeri Cowen, Forest Grove, 

 Oregon, August 25 to September 15, 1916, by Mr. L. P. Rockwood, of the 

 Bureau of Entomology, after whom the species is named. 



18— Peoc. Biol. Soc. Wash., Vol. 30, 1917. (77) 



