December, '22] severin and basinger: beet leafhopper 407 



V. Autumn and Winter Investigations 

 Cultivated Area. — ^An attempt was made to determine whether an 

 autumn dispersion to the foothills of the Sacramento Valley occurred. 

 After the beets were harvested, the leafhoppers were found on salt- 

 bushes, pigweeds and other green plants during October 1920. During 

 November and December the hoppers became fewer on green vegeta- 

 tion growing on the valley floor. The last record of the dark winter 

 adults in the cultivated area was obtained at Clarksburg on January 

 6, 1921, when eight specimens were taken on a few beets still remaining 

 in a field after the crop had been harvested. 



Foothills of Coast Range. — The most intensive investigation was 

 conducted during the autumn and winter, on the barren foothills of the 

 Coast Range and Marysville Buttes covered with the most favorable 

 winter host plant, namely, the Red Stem Filaree {Er odium cicutarium). 

 No dark winter adults were found on the foothills which had not been 

 cultivated. On the cultivated hills west of Yolo, two beet leafhoppers 

 were captured on November 3, on a small patch of Red Stem Filaree 

 growing in the vicinity of a watering trough, before the pasture vegeta- 

 tion had germinated. Specimens were also taken on weeds growing on 

 the cultivated hills and on oleander. There was very little green vegeta- 

 tion available for the insects to feed on. After the pasture vegetation 

 had germinated, a few adults were again taken on Red Stem Filaree at 

 sunset on November 28, and a half dozen males on oleander. A trip 

 was taken to the same locality on December 2, and a single male was 

 found on Red Stem Filaree, but none on oleander. 



The eastern foothills of the Coast Range bordering the western side of 

 the Sacramento Valley were examined several times from October 1920 

 to February 1921. The beet leafhopper was not found wintering over 

 on the uncultivated, barren foothills. The location of the foothills 

 examined from north to south with reference to distances and directions 

 of the nearest towns follow: 



25 miles west of Cottonwood. 



Vicinity of Newville and Paskenta. 

 12 miles southwest of Willows. 



Vicinity of Sites. 

 10 miles west of Williams. 



Vicinity of Brooks in Capay Valley. 



Vicinity of Capay. 



Yolo Hills, near Blacks. 



Vicinity of Vacaville. 



Montezuma Hills, vicinity of Collinsville. 



