THE PEA APHIS WITH RELATION TO FORAGE CROPS. 



17 



typical of the genus; more than half as long as the cornicles, bearing 

 a number of moderately long hairs. 



Measurements (averages) from three specimens, taken immediately 

 after placing in balsam and before shrinkage occurs: Length of body, 

 2.67 mm., length to tip of cauda, 3.22; width, 1.24; cornicles, 0.98 

 cauda, 0.59 mm. Measurements of antennal segments: 



mm. 



I. 



II. 



III. 



IV. 



V. 



VI, base. 



VI, fila- 

 ment. 



Mm. 



Mm. 



Mm. 



Mm. 



Mm. 



Mm. 



Mm. 



0.191 



0.087 



0.904 



0.713 



0.713 



0. 261 



1.130 



.191 



.087 



.930 



.730 



.713 



.261 



1.026 



.191 



.087 



.817 



.678 



.696 



.261 



1.026 



.191 



.087 



.800 



.678 



.626 



.235 



.974 



.191 



.087 



.887 



.696 



.678 



.261 



.991 



- .174 



.087 



.870 



.696 



.696 



.261 



1. 026 



Pupa {fourth instar) (fig. 5). — (Described from three specimens, 

 Aug. 22, 1912). Entire dorsum pale green, sometimes with a delicate 

 white pulverulence. Wing pads pale greenish with faint brownish 

 border, the tips darker brown. Underside of body with a distinct 

 white pulverulence. Eyes maroon red. Antennae with segments I 

 and II concolorous with head; III, IV, and V pale with slight brownish 

 tint and tips blackish; VI entirely blackish. Beak not reaching 

 coxae of second pair of legs. Legs with femur pale green, tibia pale 

 with slight brownish tint and blackish at the tip, tarsus black. 

 Cornicles pale green at. base, becoming whitish with a faint duski- 

 ness, the tips black; cauda concolorous with body. 



Measurements (average) from three specimens, immediately after 

 placing in balsam and before shrinkage occurs: Length of body, 2.94 

 mm., width, 1.19; length of cornicles, 0.63 mm. Measurements of 

 antennal segments : 



I. 



II. 



III. 



IV. 



V. 



VI, base. 



VI, fila- 

 ment. 



Mm. 



Mm. 



Mm. 



Mm. 



Mm. 



Mm. 



Mm. 



0.139 



0.078 



0. 556 



0.495 



0.539 



0.209 



0.834 



.139 



.078 



.539 



.487 



.548 



.209 



.S52 



.139 



.069 



.487 



.469 



.513 



.209 



.808 



.139 



.078 



.461 



.443 



.487 



.209 



.817 



.156 



.078 



.539 



.522 



.539 



.209 



.800 



.148 



.078 



.556 



.513 



.565 



.200 



.887 



Winged viviparous female (fig. 6). — (Described from three specimens 

 reared on red clover, Aug. 22 and Dec. 11, 1912.) Head pale yellow- 

 green, thoracic shield shining yellow-green, other parts of thorax 

 concolorous with the head, and abdomen pale green with the eyes 

 of the embryos showing through the skin of the dorsum as in the case 

 of the adult wingless female. Eyes bright red. Antennas (fig. 6, a) 

 placed on large frontal tubercles, and reaching beyond tip of cauda; 

 98034°— Bull. 276—15 3 



