208 Maine Agricultural Experiment Station. 1919. 



ifolii. And, as with Macrosiphum solanifolii, the migration of 

 Macrosiphum pseudorosae was not entirely complete for strag- 

 glers remained upon the rose during the summer with both these 

 species. 



All of the reared cage individuals were of the rose pink 

 color variety as, it will be remembered, were the two females 

 from which they were descended. 



Plans were made for continuing observations earlier in the 

 season during 1919 and a report upon this interesting aphid 

 was delayed with that in mind. But, although the same locality 

 was well patrolled this spring and summer not a single specimen 

 of Macrosiphum pseudorosae was found. It seems better, 

 therefore, to publish what has been ascertained with a view to 

 throwing open the situation for comparison in other parts of 

 the country. 



It would not be surprising if the name pseudorosae should 

 fall as a synonym to rosaeiformis Das, but material is not avail- 

 able for comparison and it is too far a cry from Maine to India 

 to risk on the slight acquaintance we have either with the rose 

 — ragwort species here or the "Punjab Rose Aphid" described 

 by Das. 



A full list of the food plants in India and America may 

 give a clue leading both aphids to some older name. The same 

 insect or one very closely allied is found in Maine upon Geum 

 and Cinquefoil (Potentilla) of the rose family and upon certain 

 other members of the Composite Family besides the golden rag- 

 wort, but in no case was it definitely ascertained whether it actu- 

 ally was Macrosiphum pseudorosae or a species closely resembl- 

 ing it and a further acquaintance with this aphid is desirable. 



Macrosiphum pseudorosae is a variable species with refer- 

 ence to several characters which are usually available for specific 

 determination, such as the relative length of the cornicle with 

 reference to antennal segment III and the number of antennal 

 sensoria. For instance the individuals reared on Senecio from 

 two known females removed from rose showed the following 

 variations. The size was in all the caged individuals, smaller 

 than their rose progenitors a circumstance which might easily 

 be accounted for by the fact that the basal rosettes of ragwort 

 leaves were not making succulent growth. In the apterous vivi- 

 parous females the relative length of cornicle to III of antenna, 



