Dec., '08] ENTOMOLOGICAL NEWS. 487 



pupae, or individuals with wing pads, could be found on the 

 alder tree ; but in the light of this fall's observations there 

 seems little reason to doubt that these sporadic winged forms 

 on the leaves of the alder are the return migrants from the 

 maple, and that Pemphigus accrifolii Riley is merely the maple 

 name for Pemphigus tcsscllata Fitch, the stem mother of which 

 migrates from the bark to the leaf upon hatching in the spring. 



In accordance with my custom for five years, specimens of 

 aphids have been saved, for every record made, either in 

 balsam mounts or as alcoholic material, so that they are ready 

 for reference at any time. During the winter of 1905-06 I 

 made a careful comparison of all the winged species of Pem- 

 phigus taken in Maine up to that time, and was particularly 

 struck by the fact that mounted specimens of P. tcsscllata and 

 P. accrifolii were indistinguishable and made the grumbling 

 comment "If these are two species there is no structural basis 

 for systematic work with Pemphiginae." However, there 

 seemed no place in the tessellata cycle for acerifolii, several at- 

 tempts to colonize maple with apterous forms of tessellata were 

 entirely unsuccessful and for the next two falls the species was 

 so scarce that the migrants were not much in evidence, and 

 no clue was forthcoming until this fall. 



The life cycle of the alder blight is by no means solved by 

 the location of the sexual generation. The true association of 

 P. tessellata and acerifolii yet remains to be established upon 

 *he alder. With the clues now at hand these species (two or 

 one) can unquestionably be traced in time. The abundance of 

 alder and maple at Orono and the usual presence in great num- 

 bers of P. tessellata and acerifolii make it an ideal situation 

 for work with these forms and favor my plans for thorough 

 study of the Pemphigus upon the alder and maple. 



There is no need of crowding with further details from notes 

 now at hand this preliminary paper, the object of which is 

 merely to place the sexual forms of P. tcsscllata for which the 

 following brief description will suffice. 



Oviparous female. A pale yellowish form, apterous and 

 non-rostrated, measuring 1.33 mm. in length. Antennae of 



