236 MAINS AGRICUIvTURAL EXPERIMENT STATION. I9II, 



ber 9 the apterous form and pupae of this species were found 

 colonizing on late tender growth of twig and on ventral side of 

 leaves of Spiraea Van Houttii at Orono. Aphid Nos. 17-11 

 and 75-11. 



Maerosiphuni crataegi Monell. 



This pretty yellow species with bright green abdominal spots 

 was common near Orono this season, collections having been 

 made from Crataegus at frequent intervals from July 15 to Au- 

 gust 10. Aphid Nos. 30-11, 50-11, 58-11. 



Schizoneura lanigera. 



The woolly aphid of the apple was present this season late 

 in August at Orono, Maine, in conspicuous colonies on Cra- 

 taegus and mountain ash {Pyrus sitchensis) and two other cul- 

 tivated species of mountain ash. Aphid Nos. 63-11, 64-11. 



Pemphigus rhois. 



The large and beautiful galls of this sumach aphid were sent 

 in from Machias, Maine, Sept. 5. 



Pemphigus venafuscus. 



Fall migrants of this large aphid were on the wing in Orono 

 during the entire month of October. They were seeking ash 

 trees (Fraxinus), lilac, and mock orange (Philadelphus coro- 

 narius). On account of the flocculent wax attached to their 

 bodies they resembled drifting snowflakes. 



Pemphigus tessellata (acerifolii). 



In order to ascertain whether the advent of the maple 

 migrant is an annual necessity for the development of the 

 species on the alder, a vigorous colony of hibernating nymphs 

 was enclosed in a screen house in the spring of 1909; and pro- 

 tected for 2 years against migrants from the maple. The 

 colony existed for these 2 years in a healthy condition. It is 

 of interest to note that both falls in the third generation, winged 

 migrants left the alder and not being able to reach the maple, 

 died on the inside of the screen in great numbers. A more 

 detailed account of this work will be found in the second part 

 of this bulletin. 



