COLORADO EXPERIMENT STATION. 
21 
grapes. If it becomes necessary to treat the vines lat¬ 
er than this, I would recommend using a pyrethrum 
tea in the proportion of one ounce of the pyrethrum 
to three gallons of water to be applied the same as 
kerosene emulsion as this will not injure the 
grapes. 
Pyrethrum powder is also sold as Buhach, Per¬ 
sian Insect Powder, Dalmatian Insect Powder, and 
Insect powder. The Buhach Manufacturing Co., 
Stockton, Cal., make what is usually considered 
the best article. It can be procured directly from 
the company or through local druggists. Care 
should be taken to procure a pure article. 
Tobacco-water is often recommended for the 
destruction of leaf-hoppers but it is not as cheap as 
the emulsion and it would be liable to stain the 
fruit after the latter had set. Where vines are un¬ 
der glass or can be confined under a tent, these in¬ 
sects may be completely destroyed by fumigating 
with tobacco or pyrethrum-. 
Great numbers of the mature hoppers may be 
captured upon a sheet smeared with printer’s ink, 
tar or other sticky substance and held along the 
leeward side of the trellis while some one gives the 
vines a sudden jar. 
Great numbers can also be destroyed at night by 
carrying torches through the vineyard or by burn¬ 
ing lanterns over dishes of water as the hoppers 
are much attracted by light. 
Mr. Felton, in the letter above quoted, spoke 
of a plan he tried last fall of heaping up leaves about 
the vineyard for the hoppers to collect under and 
then, on a cold day, sprinkling kerosene over the 
