Feb. js, 1915 Two Clover Aphids 433 



The lateral tubercles of the prothorax and abdomen, are distinct 

 and blunt in both the alate and the apterous generations. 



The beak in the apterous forms ordinarily reaches easily to the second 

 coxa, and in the alate forms well beyond the second coxa, sometimes 

 reaching the third. The most distinctive character of the wing is the 

 short, broad stigma with a blunt distal end. 



Aphis bakeri Cowen (Short-beaked clover aphid). 



About the middle of August, 1914, large numbers of an aphid from- 

 Trijolium pratense were taken by Mr. George Newman at Orono, Maine. 

 This species was distinct from the one just discussed, and yet I found 

 that it was commonly listed in collections as Aphis bakeri. In the 



f o^^w;;^ogoi2serf«8!toJ--:ffl^i,<ri»S55:S5 



Fig. 2. — Aphis brevis: Antenna of alate male. 



original description of Aphis cephalicola Cowen,' a synonym of A. bakeri, 

 according to Gillette and Taylor,- the specifications "Third joint of 

 antennae tuberculate, with numerous irregular sensoria, fourth with few 

 irregular sensoria," and "Beak hardly reaching second coxa" at once 

 applied to A . bakeri of this paper and distinctly did not apply to A . brevis. 

 Aphis bakeri is found also upon shepherd's-purse {Capsella biirsa-pastoris) 

 in the fall and early spring, but whether there is a migration between 

 shepherd's-purse and clover I do not know. Mr. Wilson lent me speci- 

 mens of this aphid collected from the hawthorn in Oregon. It occurs on 

 apple {Mains spp.) in Colorado.^ I have made a single collection of a fall 

 migrant on hawthorn at Orono on October i, 1914. 



The habitat of the short-beaked clover aphid on clover seemed to 

 be the ventral side of the leaf and the stem near the ground. The colonies 



Fig. 3. — .Aphis bakeri: Antenna of alate female collected from clover. 



were frequently covered by "ant sheds," as well as sometimes extend- 

 ing for a short distance underground. 



This species is smaller, more slender and graceful than the long- 

 beaked clover aphid. Joint V of the antenna is noticeably shorter than 

 IV and is without sensoria, except the usual distal one, in the summer 

 winged viviparous female (fig. 3.) The stigma is rather narrow and the 

 distal end acute. The beak hardly reaches the second coxa and fre- 

 quently falls considerably short of it. The prothoracic and abdominal 

 lateral tubercles are prominent, but very slender. Both species have the 

 cornicles and cauda very short. 



' Cowcn. J. H. (Aphiclid:ie.] /n Gillette, C. P.. and Baker. C. F. A preliminary list of the hemiptera 

 of Colorado. Colo. Atir. lixp. Sta. Bnl. ,ii {Tech. Ser. i). p. ii3. 1895. 



2 Gillette. C. P., and Taylor, V,. P. A few orchard plant lice. Colo. Agr. Exp. Sta. Bui. 133. 47 p.. 1 

 fiK., 4 pi. 1908. 



