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tomato PINWORM 
The tomato pinworm survived the winter of 1937-33 in California in large 
numbers because of mild weather and continuous growth of tomato vines, but heavy- 
losses to tomatoes did not occur during the season, except in areas of almost 
continuous tomato growing, A survey of representative tomato fields in southern 
California showed the following, degree of fruit injury: Orange County, 11 percent; 
San Diego County, 30 percent; San Bernardino County’, 3 percent; Los Angeles 
County, 23 percent; and Ventura County (Santa Rose Valley only), 10 percent. 
Thirteen tomato fields in the upland, or almost continuous tomato-growing areas 
of these counties, ranged from 5. percent to 70 percent injury, with an average 
of 32 percent, while 10 fields from the lowland, or summer-growing areas, ranged 
from none to 17 percent injury, with an average of 8 percent. Some increase in 
injury occurred late in the season but the ratio remained about the sarnie. The 
pinworm has recently been found in the Niland area of Imperial Valley,' where 
midwinter tomatoes are grown. (J. .C, Elmore, Bureau .of Entomology and Plant Quar- 
antine, U. S. D. A. ) 
Note . — According to C. A. Thomas , careful examinations of greenhouses and gardens 
in Pennsylvania in the Chester County and New Castle, Lawrence County, areas dur- 
ing the spring and summer of 1933, failed to disclose a single specimen of the 
tomato pinworm. 
BEET LEAFHOPPER * ' 
In southern Idaho precipitation above normal during April and May 1937 
caused a dense stand of Russian-thistle, the summer host plant of the beet leaf- 
hopper, to germinate. Abnormally dry summer weather reduced the suitability of 
dense stands for leaf hopper development and early fall populations were the 
lowest in the last 4 years. Above— normal fall temperature, with sufficient 
precipitation, permitted adequate fall germination of mustards, the. leafhopper *s 
natural fall and winter host plants. Consequently, the beet leafhopper left its 
holdover host with little delay and entered the winter under favorable conditions. 
The winter was extremely mild and in general was very favorable for survival. 
Surveys of the desert areas in April 1933 showed a larger overwintered population 
of leafhoppers than in any of the 3 preceding years. One of the most unexpected 
situations occurred during the warm days of April and the early part of May, when 
a movement of overwintered leafhoppers migrated into the cultivated area. An 
average of 24.4 leafhoppers per 100 feet of row of beets was recorded for south- 
central Idaho, and undoubtedly this large movement affected the magnitude of the 
spring generation in the desert. The initial movement of the spring generation 
occurred on May 26, which is the average date for the last 13 years', and the peak 
was reached on June 17 . The premature drying of annual spring-breeding wild host 
plants, in the Sailor Creek sagebrush section, lying south of the Snake River and 
west of the Salmon Falls Creek, together with the area west and northwest of the 
Jerome cultivated tract, was very important in reducing the abundance of the 
spring generation of leaf hoppers . The number of leafhoppers in the spring move- 
ment in 1938 was approximately two-thirds as large as in 1935, four times as "large as 
in 193 o, and one- third as large as in 1937 * In a small number of fields, where 
eets followed be "ts and where a few 1937 volunteer beets were still growing 
the ov -rwintered beet leafhopper that entered the fields early in the seas on’trans- 
mitted the curly top disease from the volunteer to the seedling beets during their 
most susceptible stage, which resulted in reduction of yields, ranging from 25 to 
