64 PAPERS OX INSECTS AFFECTING VEGETABLES. 



These mixtures have been applied to sugar beets with various types 

 of sprayers (figs. 15-22) at the rate of from 80 to 125 gallons per acre, 

 and the results have been uniformly successful in controlling the web- 

 vrorms. As a rule, 100 gallons- per acre should be applied and the 

 spraying commenced as soon as possible after the webworms have 

 hatched. TVTiere possible the spray should be applied at about 80 

 pounds pressure, although the writer has observed good results where 

 only 40 to 50 pounds pressure was maintained. The leaves of sugar 

 beets are quite smooth, and in order to apply an even coat of poison it 

 is necessary to add some adhesive to the spray mixture. In the 

 writer's experience nothing has proven more satisfactory for this 



Fig. 15. — Barrel sprayer suitable for use against the sugar-beet webworm. (Original.) 



purpose than whale-oil soap. If it is not obtainable, ordinary laun- 

 dry soap may be used with about equally beneficial results, although 

 it is more expensive. Lime, as recommended in formula No. 2, serves 

 to an extent as an adhesive and has the additional effect of neutraliz- 

 ing any free arsenic which may be present in the Paris green. Lime, 

 however, renders the mixture somewhat caustic, and this formula is 

 less pleasant to use than is one in which soap is used as the adhesive 

 agent. 



Refuse molasses from the beet-sugar factories was given extensive 

 tests as a substitute for soap, and when used at the rate of from 3 

 to G gallons in 100 gallons of mixture it served as an effective ad- 

 hesive. The molasses, however, contains a considerable amount of 



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