90 APHID NOTES 



Microsiphum canadensis (Williams) (Plate "\'I, figs. 1 to 7.) 



Cryptosiphum canadensis ( Williams). ■* 



Except for a difference in color there is practically no difference 

 between this species and M. (Chaitophorus) arteinesiae Gillette. 

 M. oregonensis differs from the latter in the specialized setae, so 

 that there is a possibility that these species may be only different 

 forms of the same species. 



Apterous viviparous female: General color pale green. Antennae deep 

 black at the tip and through segments 4 to 6; third segment dusky at the 

 distal end and shading to light gi-een at the base. Legs with the tarsi and 

 tips of the tibiae and femora black, the other parts dusky. Body globular 

 and broadly ovate from above; sparsely set with heavy blunt setae. Antennae 

 as long as the body and on semi-distinct tubercles. Third segment with one 

 large sensoria near the base (notes from type slide in U. S. Nat. Museum). 

 Davis ^ has figured this segment with 5 small sensoria; nectaries about as broad 

 as long and tapering. Cauda very short and broad. 



Measurements: Length of body, 1.9 mm.; width, 1.22 mm. Length of 

 antennal segments: III, 0.4 mm.; IV, 0.4 mm.; V, 0.2 mm.; VI, 0.11 mm.; 

 spur, 0.55 mm. Length of nectaries, 0.45 mm.; length of cauda, 0.45 mm. 



Alate viviparous female: General color, head and thorax dusky or black, 

 abdomen dark green ?, nectaries and cauda dusky to black. Abdomen wide 

 and rounded; tip widely rounded, and not pointed as in other species. Anten- 

 nae as long as the body, black at the tips and lighter at the base. Antennal 

 tubercles distinct but not extensive. Third antennal segment with from 2 to 

 4 large sensoria. Wings with normal venation but with veins slightly dusky. 

 Nectaries short, slightly tapering and about as broad as long. Cauda trian- 

 gular and acute at the tip. 



Measurements: Length of body, 1.45 mm.; width, 0.9 mm. Length of 

 antennal segments: III, 0.33 mm.; IV, 0.27 mm.; V, 0.27 mm.; VI, 0.135 mm.; 

 spur, 0.622 mm. Length of nectaries; length of cauda 0.066 mm.; length of 

 wing, 2.1 mm.; width, 0.84 mm. 



Microsiphum artemesiae (Gillette) (Plate VI, figs. 8 to 16.) 

 Chaitophorus artemesiae Gillette. ^ 



Collected on Artemesia tridentata at Salisbury, Oregon, July 

 26, 1914. 



Apterous viviparous female: General color wine red and shining. In this 

 case not brownish lilack as in the original description. Antennae black at the 



^ "The Aphididae of Nebraska," University of Nebraska Studies, X, no. 2, 

 p. 89. 



^ WiUiams, "The Aphididae of Nebraska," a critical review, ibid, XI, 

 no. 3, July 1911, plate I. 



BEnt. News, XXII, p. 443, 1911. 



