98 APHID NOTES 



normal. Nectaries thick, long and almost cylindrical but with a slight taper. 

 They reach to about the tip of the cauda, which is similar in shape to that of 

 the apterous form. 



Measurements: Length of body, 2 mm.; width, 0.9 mm. Length of anten- 

 nal segments: III, 0.75 mm.; IV, 0.51 mm.; V, 0.47 mm.; VI, 0.154 mm.; spur, 

 0.75 mm. Length of nectaries, 0.52 mm.; length of cauda, 0.27 mm.; length of 

 wing, 4 mm.; width, 1.34 mm. 



Macrosiphum ludovicianiae Oestlund (Plate VIII, figs. 1 to 5.) 



Collected at Corvallis, Oregon, July 2, 1911. On Artemesia 

 vulgaris and on the same plant at Salisbury, Oregon, July 26, 

 1914. A very large greyish green species feeding mostly on the 

 stems. 



Apterous viviparous female: General color pale green, entire body covered 

 with a fine white powder, eyes reddish. Antennae longer than the body and 

 black except the first and second segments and the basal half of the third which 

 are dusky. Legs black except the basal part of the femora. Nectaries black 

 and cauda yellow. Third segment of antennae with 9 to 12 visible irregular 

 sensoria, which are more or less roundish in shape. Nectaries and cauda as 

 in the alate form. 



Measurements: Length of body, 2.5 mm.; width, 1.1 mm. Length of anten- 

 nal segments: III, 1.11 mm.; IV, 1.07 mm.; V, 0.86 mm.; VI, 0.3 mm.; spur, 

 1.25 mm. Length of nectaries, 0.86 mm.; length of cauda, 0.53 mm. 



Alate viviparous female: General color light green; abdomen and legs 

 covered with a white powder which gives them about the color of the plants 

 upon which they are found. Eyes red. Antennae deep black except the two 

 basal segments and a part of the third. Legs dusky to black except the basal 

 one-third of the femora which is fighter. Nectaries black, cauda yellowish 

 green. Antennae longer than the body and on strong tubercles. Third 

 segment with about 55 visible sensoria, variable in size and oval to round in 

 shape; the fourth segment apparently has none and the fifth bears one large 

 one near the distal end. Sixth with the usual sensoria at the base of the spur. 

 Nectaries somewhat slender and tapering; thickest at the base and flanged at 

 the tip ; the distal half distinctly different in appearance from the basal half 

 on account of the reticulated surface. Cauda nearly as long as the nectaries 

 and shaped like a spear head with the broadest part in the middle. 



Measurements: Length of body, 3 mm.; width, 1 mm. Length of antennal 

 segments: III, 1.22 mm.; IV, 1.08 mm.; V, 0.9 mm.; VI, 0.3 mm.; spur, 1.24 

 mm. Length of wing, 4 mm.; width at widest part, 1.31 mm. Length of necta- 

 ries, 0.71 mm.; length of cauda, 0.51 mm. 



