BULLETIN 241. 



WOOLLY APHID OF ELM AND JUNEBERRY.* 

 {Schizoneura americana in part, of authors.) 



Edith M. Patch. . 



Each season considerable concern is exipressed by residents 

 of Maine relative to certain deformations of elm leaves due to 

 the work of aphids. Indeed so unattractive do young elms 

 appear when heavily infested that it sometimes seems desirable 

 to the owners to remove them from the lawn. 



Several species cause distortions of these leaves, one of which 

 is treated in this paper in such a manner as to outline the chief 

 points in its life cycle. 



Familiar to all observers of the American Elm are leaves one 

 edge of which is rolled under as is shown in Figure 45. Such a 

 curl constitutes a protective habitation for a family of aphids 

 during their spring residence there. 



The mother of the colony is a large plump, somewhat powdei}' 

 aphid' which, if examined in the sunlight under a lens, is found 

 to have a greenish complexion. She passes the winter in the 

 egg stage hidden in the crevices of the elm bark. In the spring, 

 hatching from the egg just as the leaves are unfolding, she seeks 

 a suitable one, punctures it with her beak and by remaining and 

 feeding causes it to curl into the protecting roll. Early in June 

 she has attained her full growth and the leaf in which she has 

 been dwelling looks like the left hand leaf of Figure 45. She 

 now gives birth to a large number of young, which, unlike their 

 mother are born alive, not undergoing any external egg stage. 



Her progeny are all females which upon attaining their 

 growth give birth in turn to living young, — also all females. 



*Papers from the Maiine Agricultural Experiment Station : Ento- 

 mology No. 79. 



