178 JOURNAL OP ECONOMIC ENTOMOLOGY [Vol. 1 



The pup^e, while much resembling those of gossypii, do not have the 

 tessellated dorsal spots so silvery white. 



The young larval forms do not have the characteristic yellowish 

 brown color of gossypii upon the dorsum of the abdomen nor the 

 green transverse band, and there is not the range of light and dark 

 forms among the apterous lice found in the colonies. 



The tibiae and basal half of the antennae are more conspicuously 

 whitish than in allied species. 



This species has been specially partial to white sweet clover and 

 Glycerrhiza lepidota here, two plants upon which we have never taken 

 any of the allied species. 



Sexual forms and eggs we have not been able to find. 



Aphis rumicis Koch. 



It seems almost certain that several writers, including Oestlund in 

 his description,^ have reported medicaginis as rumicis. I do not think 

 that the rumicis of Linnanis has come under our observation, unless, 

 possibly, it proves to be the same as carhocolor Gill. 



Aphis carhocolor Gill. 



This louse is somewhat larger and more robust than medicaginis, 

 the adult apterous individuals are all deep dull sooty black, never 

 polished, and it passes into the sexual forms in the fall, the females 

 of which deposit eggs in great numbers about the crowns and bases of 

 the leaves and stems of species of Rumex, especially the yellow dock. 

 The cornicles are decidedly shorter and weaker than in gossypii or 

 medicaginis. Winged viviparous females are shining black upon both 

 thorax and abdomen. The seventh antennal joint and the antenna 

 as a whole are longer than in medicaginis. 



Aphis oenothericE Oest. 



This louse has been considered a synonym of gossypii by Sanborn, 

 which is probably a mistake as this is a green louse, occurring upon 

 the primrose only, so far as we have observed, and never having the 

 black apterous females of medicaginis nor the variety of colors ex- 

 hibited by gossypii. It is possible that Prof. Sanborn had true 

 gossypii from Oenothera and that he had not seen true oenotherice, 

 which is a very common species in Colorado and quite distinct from 

 gossypii. 



Aphis forhesi Weed. 



I would not include this species as belonging to the gossypii group 

 were it not for the fact that it has been confused with Aphis gossypii 



sBull. 4, Synopsis of the Aphididae of Minn. p. Gl. 



