432 Journal of Agricultural Research voi. m. No. s 



27 these adults had lost the rosy hue they had as nymphs and had become 

 creamy white or grayish white with black antennae, dusky legs, and deep 

 rusty spots at base of cornicles, but with no rusty line connecting them. 



On August 5, 1912, my attention was called to infested sweet-pea 

 {Lathyrus odoratus) vines, which had vigorous colonies of red aphids on the 

 stems at the surface of the ground extending for an inch up the plants. 

 These proved to be the long-beaked clover aphids, and the source of the 

 infestation doubtless was the hawthorn tree a few rods distant which 

 had been heavily attacked by the spring generations of this species earlier 

 in the season. 



The spring forms on the hawthorn include two types of apterous 

 females. One, possibly the stem mother, has the head, prothorax, 

 and thorax soft coral pink. Joints I, II, and III of the antenna are 

 coral pink or pellucid, while the other joints are black. The abdomen 

 is olive green mottled with brown and pink, with a slight bloom only. 

 The very short cornicle is light pellucid with the merest dusky tip, 

 and the very short cauda is dark brown. 



The apterous female of the second (or third?) generation has the 

 head, prothorax, and thorax crimson, overcast with a slight bloom. 

 Joints I, II, and III of the antenna are pellucid, while IV, V, and VI 

 are black. The abdomen is crimson mottled with olive green and 



6^- 



Fig. I. — Aphts brei'is: Antenna of fall alate female collected from hawthorn. 



covered with slight bloom. There is a pale olive space about the base 

 of the short cornicles, which are light olive green. 



The spring migrant before flight has the dorsal surface of the head 

 shining black, the ventral reddish, with a black beak and the anteimae 

 black; the prothorax is black with red membrane; the dorsal lobes of 

 the thorax are shining black, the breast reddish black; the dorsum of 

 the abdomen is red in form of a heavy cross, the part about the cor- 

 nicles being pale olive green; the venter is red. These same migrants 

 after feeding on clover juice lose with age their reddish cast, the abdo- 

 mens then becoming olive green. 



The nymph, which is to become the spring migrant, in the pre-imago 

 stage has its head and thorax coral pink, its abdomen red and more 

 or less mottled, with a pale olive green space about the cornicle extend- 

 ing over several segments. 



The fall alate form does not differ essentially from the spring migrant. 

 The sensoria of the antenna (fig. i) are distributed over joints III, IV, and 

 V, in practically the same numbers as the spring migrant, although 

 some individuals of the spring form have fewer to none on joint V. 

 V and VI are nearly subequal, and they are both sometimes longer than 

 those shown in figure i. Joint V is sometimes a little shorter than IV. 



Joints IV, V, and VI in the male are relatively longer than those in 

 the alate female and there are frequently more sensoria on IV and 

 V, as well as sometimes from one to several on basal part of joint VI 



(fig. 2). 



