WOOLLY APHID ON ELM AND JUNEBERRY. 20I 



Where the Amelanchier is planted for park or ornamental purposes 

 within aphid flight of American Elm, it would seem desirable to tiy 

 drenching the -soil at the base of the ishrub with Black Leaf 40 or other 

 good tobacco decoction. Probably once about mid-July and again laie 

 in the month would be the most favorable time for this treatment as 

 the colonies would be young and susceptible and likely to be nearer the 

 surface than later in the season. 



Young elms can be protected by spring sprays of tolsacco decoction 

 before the leaves become curled. Where large power sprayers arc 

 available old elm's sprayed with drive nozzles could probably be cleanea 

 of most of the infestation. 



Dormant sprays -oi lime sulphur heavily coating the elm bark shoula 

 be tested as to their efficiency in killing the over-wintering egg. 



Notes. 



The species discussed in this paper under the title "Woolly Aphid of 

 Elm and Juneberry" is the same species which is listed as CCC in the 

 Habitat Key on page 184 of Bulletin Xo. 217 of this Station, and re- 

 corded on pages 268-271 of Bulletin Xo. 220. 



As the alternate or summer host of this species has not previously 

 been published, it seems desirable to state here the data upon which this 

 life cycle is recorded. 



On June 28, 1911, a collection of winged forms of this species from 

 Amelanchier canadensis (L.) Medic, was made by Mr. William Woods 

 and mounted by my assistant under the number 15-11. As Prociphilus 

 corrugatans is commonly taking flight from the leaves of Juneberry late 

 in June, I took it for granted that 15-11 was probably that species and 

 did not examine the material until 1914 when I was startle'd to find 

 that all this collection was Schizoneura americana of the elm leaf curl. 



X^o additional data were obtained last year but on June 25, 1915, 

 Mr. Woods brought into the laboratory about 30 migrants stating that 

 they were abundant and occurring singly on the underside of the June- 

 berry leaves. Upon examination, I found these to be Schizoneura 

 americana and as they had been collected about three-fourths of a mile 

 from the nearest known elm, the situation was given immediate atten- 

 tion. I visited the place in the college woods where Mr. Woods had 

 made his collection (50-15) and found the migrants resting upon the 

 underside of the leaves of almost all of the numerous Juneberries in 

 that vicinity, and did not find them settling upon other vegetation there. 

 Upon some of the Juneberry leaves the minute yellowish young of the 

 migrants were found, and it was an easy matter to locate on the undei- 

 ground stems of these shrubs, the colonies of young, already grouped 

 about some favorable ,spot and covered by a slight waxy secretion. 



Three young Juneberries were potted and brought into the laboratory. 

 Migrants were removed from elm curl and caged with these plants. 

 They settled on the ventral side of the leaves and remained there several 

 days giving birth to their young which sought the underground stem of 



