THE CANADIAN ENTOMOLOGIST. 



peas eight or ten years ago." In 1S87 an aphid very similar to this 

 species, and probably the same, was observed by Dr. L. O. Howard, 

 U. S. Entomologist, on clover at Washington, D. C. Mr. R. H. Pettit, 

 of the Mich. Agl. Experiment Station, informs me that one or two 

 Michigan pea growers state that they have known a similiar plant-louse to 

 infest peas for the past twenty years. 



Fall Migratory Winged Viviparous Female. — Wing expanse, 9.3 

 mm. Length, 3.15 mm.; width, 1.05 mm. ; Antennae, 3.9 mm., III., 

 0.88 mm.; IV., 0.81 mm.; V., 0.72 mm.; VI., 0.28 mm.; VII., 0.97 mm. 

 Tibia, I., 1.62 mm., II., 1.62 mm., III., 2.25 mm.; Cauda, 0.42 mm.; 

 Cornicles, 0.70 mm. Average of 13 specimens. 



Coloration same as male, except chitinous plates are slightly 

 lighter, lateral spots and those above spiracles in abdomen are wanting, 

 with two dark spots on subgenital plate, subventral plate green, lacking 

 sensoria on V. antennal segment. 

 Apterous Viviparous Female. 



Specimens late in October and in November are more or less 

 covered with a distinct whitish pulverulence, are smaller, and darker 

 green than in the summer. 



Larva? of these same broods have antennae, cornicles and legs 

 blackish or dark brown, body with more or less whitish pulverulence, 

 which is especially marked and distinct on distal half of hind tibia ; very 

 different from larvae in spring or summer. 



Winged Male. — Wing expanse, 9 mm.; Length, 2.5 mm.; width, 

 0.95 mm.; Antennae, 3.62 mm.; III., 0.77 mm.; IV., 0.71 mm.; V., 

 0.73 mm.; VI., 0.23 mm.; VII., 1.02 mm.; Tibia, I., 1.57 mm.; II., 

 1.50 mm.; 111., 1.90 mm.; Cauda, 0.24 mm.; Cornicles, 050 mm. 

 Average of 3 specimens. 



Dorsal aspect head yellowish, ocelli black, eyes red, mesal line 

 darker, a dark spot either side of meson caudally; ventral aspect head 

 and thorax yellow, except mesosternum which is deep olive brown to 

 blackish, shining, chitinous; rostrum reaches to centre of mesosternum, 

 prothorax dorsally yellowish-green, thoracic dorsal plates dark-olivaceous 

 to blackish ; legs yellowish or reddish brown, tips of femora and tibia, and 

 tarsi black ; large blackish pleural spot on either side of mesothorax and 

 two smaller spots caudad of it at bases of mesa and meta coxae ; abdomen 

 light green, slightly whitish pulverulent, three or four lateral blackish 

 spots cephalad of cornicles ; cornicles green, tips black ; cauda green ; 



