INJURIOUS INSECTS. IO3 



lest there be danger of poisoning the human, as well 

 as the insect, consumer. Yet the owner of the fields 

 upon which the tests have been made says, "I am 

 satisfied that it would have paid me to spray the 

 entire field."* 



Cost of Treatment. — ^To make two applications 

 upon ten acres of late cabbage after the plants are 

 two-thirds grown would require materials worth 

 $5.00, time in preparing stock solution, 75 cents,, 

 and ten days' labor, which at $1.50 a day would be 

 $15.00, a total of $20.75, or about $2.00 per acre. 



Precautions. — As noted before, a strong, well 

 made knapsack sprayer must be used, as the mixture 

 is liable to clog valves and nozzles and cause severe 

 straining of a light sprayer. The workman must 

 be close to his work and must thoroughly coat every 

 leaf, both upper and under surface. There is but 

 very slight danger of poisoning cabbage with the 

 mixture, as only the outer leaves are touched by the 

 spray and these are thrown away in preparation for 

 the table. Cauliflower must not be sprayed after 

 the "flower" is exposed. Only careful workmen 

 should be trusted to make the late spraying upon the 

 cauliflower, and all heads should be passed over that 

 are too far advanced.f 



*In addition it has been found that in using the resin-lime solution upon 

 rapidly growing cauliflower warty excrescences are formed upon the leaves, 

 thus indicating a slight injury. Hence for cauliflower it is more safe to use 

 only half the quantity of resin solution and lime. 



fOtlier Measures— Since the above was published, it has been found that 

 the new arsenate— arsenate of lead— is much easier to prepare and apply, and 

 if care is used to apply it lightly and in a perfect mist while the plants are 

 dry, it will be evenly distributed and when once dry will adhere nearly as well 

 as the resin-lime solution. It has the further advantage of never injuring the 

 plants. Many growers practice the use of dry Paris green applied by means 

 of blowers or powder guns. Frequently the Paris green is diluted with flour 

 or with airslaKed lime, using ten or fifteen parts of the flour to one of the arse- 

 nate. This answers fairly well, if applied while the plants are covered with a 

 light dew, but a light rain or a heavy dew soon washes it into the folds of the 

 leaves, vrith the result of burning. Furthermore this method is of little value 

 in controlling the cabbage looper. 



