39 ENTOMOLOGICAL NEWS. [March, 



Notes on a New Sugar-Beet Pest, with a Description 



of the Species. 

 By R. W. DOANU, 



Washington Agricultural College and School of Science, 

 Pullman, Washington. 



The way in which a seemingly harmless insect may, under 

 changed conditions, become, in a very short time, of serious 

 economic importance is well illustrated by a species of Aphis 

 that has been giving more or less trouble to beet-growers of 

 this section during the last two or three seasons. We have 

 here, feeding upon the roots of the Polygommi aricnlare and 

 Achillca millefolium, and more rarely on other plants also, a 

 species of Aphis, which, while seldom occurring in large colo- 

 nies, is pretty well distributed throughout the soil wherever 

 these plants grow. The large amount of the white flocculent 

 secretion with which the insect is covered makes its presence 

 easily detected; the little spaces where the roots formerly ran, 

 and any cracks or crevices in the soil near the infested plants, 

 are more or less completely lined with this substance, which 

 looks very much like a white mould, and indeed is often mis- 

 taken for such. 



As long as this insect attacked only uncultivated plants, 

 little or no attention was paid to it. But during the last three 

 years it seems to have developed a remarkable liking for sugar 

 beets, with a result that those interested in the growing of this 

 plant have suffered considerable loss from the ravages of this 

 new 7 pest. If the season is favorable and the insect attacks 

 the beets early, the yield may be very materially affected. It 

 feeds wholly on the roots sometimes occurring in sufficient 

 numbers to entirely destroy the smallest rootlets ; thus, of 

 course, stopping the growth of the plant, and causing it to 

 shrivel and become spongy. Certain growers report a large 

 part of their crop thus destroyed ; while others have only suf- 

 fered from having the yield more or less decreased. In a bul- 

 letin soon to be issued by this station, the life-history of this 

 insect, so far as it is now known, will be given in detail. Only 

 brief notes need be given here. 



The colonies found during the winter months consist of a 



