TENTH ANNUAL EEPORT OF STATE ENTOMOLOGIST 53 



in nearly every apple orchard and in some cases was abundant 

 enough to destroy the current season's growth. It may easily be 

 controlled by spraying with tobacco extract. 



The Woolly Aphis {Schizoneura lanigera Hansen). This im- 

 portant fruit pest has now established itself throughout the Bitter 

 Root Valley and promises to be very troublesome in unsprayed 

 orchards. Inspectors report that in orchards systematically sprayed 

 with lime-sulphur it soon dies out. 



The Black Cherry Aphis ( Myzuscerasi Fab.). This plant 

 louse is becoming more abundant each year and will soon be found 

 wherever cherries are grown. 



The Cabbage Aphis {Aphis brassicae L.). This is always 

 present in Montana cabbage fields and is the subject of many let- 

 ters to the state entomologist. This and other cabbage pests are 

 treated in a circular about to be published. 



The Sugar Beet Root Louse {Pemphigus hetae Doane). 

 This is a leading pest of the sugar beet, but not as bad this year as in 

 former years. New facts concerning its life history and control 

 have been obtained during the year and will be published the 

 coming summer. This study has been undertaken under the Adams 

 Fund. 



The Elm Gall Louse {Schizoneura americana Riley). This 

 is our worst shade tree pest; each year it seriously deforms the 

 foliage and checks the growth of our elms. This year it was 

 especially abundant in Kalispell and Billings. In some cities it is 

 being controlled by spraying with tobacco extract early in the 

 season before the leaves have become deformed. This louse leaves 

 the elm in July and late spraying is, therefore, useless. 



Much interest is attached to this insect because of the recent 

 assertion of an eastern entomologist that it is identical with the 

 woolly aphis of the apple. 



Cottonwood Aphis {Arctaphis sp.). Several letters were re- 

 ceived stating that plant lice were injuring Cottonwood trees. Spec- 

 imens were not sent, but it is probably the work of an unnamed 

 aphis {.Arctaphis sp.) which was mentioned in last year's report. 



Wheat Aphis {Brachycolus sp.). A trip was made to the 

 Judith Basin to investigate the work of an aphis which caused 

 considerable loss in 1911. Only a few lice were found, due probably 



