94 APHID NOTES 



tubercle on each side just behind the metathorax. Nectaries thicker at the 

 base and at the tip than in the middle. Flange at the tip broadest part of 

 nectaries. Cauda short, tapering and turned upward. 



Measurements: Length of body, 1.2 mm.; width, 0.5 mm. Length of 

 antennal segments: III, 0.198 mm.; IV, 0.11 mm.; V, 0.135 mm.; VI, 0.01 mm.; 

 spur, 0.176 mm. Length of nectaries, 1.54 mm.; length of cauda, 0.05 mm.; 

 length of wing, 1.62 mm.; width, 0.67 mm. 



Aphis tridentatae new species (Plate VII, figs. 26 to 30.) 



Found in company with M. artemesiae Boyer and Ch. triden- 

 tatae during May and June. 



This species resembles Ch. tridentatae on the plants and the 

 only distinction is the wider body and pinkish color of some 

 individuals. iTnder the microscope the spines are found to be 

 different and the presence of well developed nectaries readily 

 separates this species from the other. There is no present genus 

 into which this species can be placed so it is deemed best to desig- 

 nate it as an Aphis for the time being. 



Apterous viviparous female: General color light pink or white, covered with 

 numerous white fan-like specialized setae. Antennae black at the tip shading 

 to dusky at the base; legs dusky at the tip of the femora and tibiae and the 

 tarsi black. Head shghtly convex, abdomen obovate, caudal end broadly 

 rounded, cauda not apparent from above, very short and rounded. Antennae 

 slightly longer than one-half the body and antennal tubercles present as ridges. 

 Antennae without specialized setae. Legs sparsely set with setae like those 

 on the body but not quite so heavy. Eyes hardly tuberculate. Nectaries 

 curved and clavate with the tip cut obliquely. In many individuals the 

 nectaries cling so closely to the body that they cannot be seen. 



Measin-ements: Length of body, 1.54 mm.; width, 0.8 mm. Length of 

 antennal segments: III, 0.14 mm.; IV, 0.135 mm.; V, 0.135 mm.; VI, 0.11 mm.; 

 spm", 0.22 mm. Length of nectaries, 0.22 mm.; length of cauda, 0.45 mm.; 

 length of speciaUzed setae, 0.045 mm. 



Alate viviparous female: General color pink or light green with hght Ijrown 

 head and thorax. Antennae black at the tip and shading to hght or dusky 

 green at the base. Legs with femora light, tibiae dusky and tarsi black. 

 Cauda hght gi-een. The spines are not nearly as numerous as in the apterous 

 forms but they are sparsely found over the entire body and on the legs. Those 

 on the legs are much finer than those on the body. Antennae normally 

 nearly as long as the body and rather slender. Third segment with 4 round 

 sensoria placed as in drawing. Wings long and slender, venation normal. 

 Nectaries as in the apterous form. Cauda almost cylindrical and extending 

 slightly beyond the tip of the abdomen. 



Measurements: Length of body, 1 mm.; width, 0.35 mm. Length of anten- 

 nal segments: III, 0.2 mm.; IV, 0.176 mm.; V, 0.154 nun.; VI, 0.09 mm.; spur. 



