THE SO-CALLED TOBACCO WIREWORM IN VIRGINIA. 17 



4 acres. It was in corn during the season of 1910. Previous to plow- 

 ing for corn the field was in weedy sod. The corn was badly injured 

 by the Crambus and was replanted twice. At the last cultivation of 

 corn in July, crimson clover was sown. Rains were frequent during 

 the latter part of the summer, and a fairly good stand of clover was 

 secured. There were some weeds, in spots, which cultivation at the 

 time clover was sown had not destroyed. The field was planted to 

 tobacco during the season of 1911. Damage by the Crambus was 

 estimated to be about 6 per cent. 



A test with tobacco following cowpeas was conducted as a coop- 

 erative experiment on the S. L. Ferguson farm, Appomattox County, 

 Va., in the seasons of 1911 and 1912. A held containing about 6 

 acres was used in the experiment. The land previous to plowing for 

 cowpeas was in weedy pasture, and numerous Crambus larvas had 

 been observed. A good growth of the cowpeas was secured. The land 

 was deeply plowed during winter and was prepared for planting to 

 tobacco during the third week in May, 1912. Scarcely any injury 

 from the Crambus to the first planting was observed. After the first 

 planting damage from the Crambus and from other causes was esti- 

 mated to be less than 4 per cent. In the check field, where conditions 

 were similar to those in the experimental field, except that a crop of 

 cowpeas had not been grown, there was an estimated damage from 

 the Crambus of about 9 per cent. The sod in the check had been 

 winter-plowed. 



In the plats of the Virginia Tobacco Experiment Station, at Appo- 

 mattox, nine'experiments were under observation, as detailed below. 



The first experiment was with tobacco planted on sod in an old 

 weedy pasture. A large part of the first planting was destroyed. 

 The plat was replanted three times. About 9 per cent of a stand was 

 secured by the second week in July. Owing to injury from " wire- 

 worms" and the large percentage of late plants the value of the crop 

 was decreased 25 per cent as compared with plats in which an early 

 stand of plants had been secured. 



The second experiment was with tobacco following cowpeas on 

 land that had been uncultivated for several years and was very weedy. 

 Almost a perfect stand of plants was secured at the first planting, 

 which was made the last week in May. The injury (decrease in the 

 value of the crop) was less than 1 per cent. 



The third experiment was on a plat used for fertilizer tests. The 

 condition of the land was similar to that used in the second plat, 

 except that cowpeas had not been grown during the preceding season. 

 The tobacco was replanted three times. The decrease hi the value 

 of the crop was 7 per cent. 



