£>35- 
variotv grown extensively in southern Idaho. Fall populations of . the beet leaf- 
hopper in southern Idaho in 1939 rare the lowest recorded since the institution 
of the extensive fall population survey in 1934 to obtain information on the 
number of leafhoppers that may enter the -inter. Weather conditions early in 
October —ere generally favorable for fall germ in at ion of the fall and winter 
hosts of' the beet leofhcppor, A survey of the desert breeding areas in November 
revealed that a very sparse, though general, germination of the weed host of 
this insect had. occurred in all sections of southern Idaho* Weather conditions 
up to the middle of December have been favorable for , leaf hopper survival. 
Overwintering beet leafhoppers were found at l 6 of the 21 points examined 
in the Billings, Mont., area in April, indicating a comparatively high. winter- 
survival for Montana, The infestation extended down the fellows tone Riv r fallo» 
from Columbus to Custer, Mont., a distance of 96 miles. „ Excessive precipitation 
( 9 .O 5 inches), combined with low temperatures during the last half of May -and 
the first 20 days of June, was evidently the important factor in limiting re- 
production. A survey of beet fields in the Billings area in August revealed a 
very light infestation. A survey of beet fields for overwintered beet leaf- 
hoppers' in the Nyssa, Or eg. , .and Toppenish, Wash., districts in the last few days 
of April showed the pr sence of overwintered leafhoppers in all fields examined. 
The infestation per field in the Oregon area ranged from 8 to 24, with an aver- 
age of 15*6, and in the Washington area from 3 to 37* with. an average of 13 leaf- 
hoppers per 100 feet of row. The infestation of overwintered beet leafhoppers 
in be t fields in south-central Idaho averaged 5*4 per 100 feet of row the first 
few days of May. (J. R. Douglas, Bureau of Entomology and Plant Quarantine, 
U. S. D. A.) 
In northern Utah the lack of precipitation in April and May 1933 reduced 
the gemination of Sals 0 la pestifer . the summer host plant of the beet leaf- 
hopper. In its place, 3 r emus spp. germinated very early in the, spring and uti- 
lized the late winter precipitation. The stand of Russ ian- this tie in the fall 
of 1933 was still reduced, but the population of the beet leaf hopper was similar 
to 1936 • The -inter and spring host, Erodium cicutarium . germinated early in 
the fall and the leafhoppers made a direct transfer from the summer host. The 
population of the leafhoppor on the Promontory Points breeding area in the spring 
of 1939 was much higher than in 1933* The percentage of viruliferous beet leaf- 
hoppers of the overwintering type was, however, about one- third as high as 1937 
and t-o-thirds of that of 1933. The percentage of viruliferous beet leafhoppers 
from the first bre^d, or the brood that moves to the cultivated crops, maintained 
a low percentage of viruliferous hoppers, since the percentage was about half 
that of 1937 and one-third that of 1933. The peak of the local migration occurred 
about June 1. The damage to tomatoes -as- noticeably less than in 1933 or 1937* 
The damage to sugar beets was less than in 1933. (H. E. Dorst, Bureau of Entomol- 
ogy and Plant Quarantine, U. S. D. A.) 
BEET WEBWORM 
From 1936 to 1933, inclusive, the beet wobworm was a pest of considerable 
economic importjin.ee on beets in south— cent ral Idaho. Approximately 4,000 acres 
of beets were sprayed each season. During this period the infestation occurred 
in practically the same localities^ year after ye-r. The first flights of moths 
noted in 1939 were in the Castleford and Burley areas on May 10 and 11, respective, 
ly. Eggs w re numerous in beet fields on June 3 and occasionally a worm was 
noted. Very few of these eggs hatched. From about June 10 to June 24, worms were 
