INSECTICIDES 57 



a stomach poison and a contact poison are all mixed together 

 forming what might be called a " complete spray." 



Arsenical poisons, and in a very few instances contact insec- 

 ticides, are sometimes applied in the dry form as dusts, the process 

 being called dusting or, less properly, dust-spraying. Truck 

 crops may be dusted on a small scale without special machinery 

 and the method is therefore often more convenient for the small 

 gardener than spraying. Recent experiments have shown that 

 dusts are as effective as sprays in controlling the insects which 

 affect most orchard fruits and foliage. The method has not been 

 generally adopted as yet for the reason that it is still doubtful 

 whether dusts as at present used will entirely control the fungous 

 diseases of the orchard. This in spite of the fact that dusting was 

 first extensively used to control a fungus disease, the mildew of 

 grapes. Dusting has many advantages over spraying, notably, 

 its greater rapidity, it being possible for one outfit to dust as much 

 in a day as several spray outfits can cover, and the elimination of 

 the necessity to provide a water supply for the sprayers, also the 

 consequent lightening of the outfits due to the elimination of the 

 water. It is therefore to be hoped that the method will be devel- 

 oped so that it is applicable for all the pests of the orchard. 



Stomach poisons are frequently used in the form of baits 

 rather than applied directly to the plants to be protected. In 

 such cases substances attractive to the insects are poisoned and 

 placed where they can get them easily, usually near the plants. 

 The most commonly used bait is poisoned bran-mash prepared 

 according to a formula based on old usage but perfected at the 

 Kansas Experiment Station. It is made as follows: 



Bran 20 Ibs. 



Paris green 1 Ib. 



Cheap syrup 2 qts. 



Water 3 1 A gals. 



Place the Paris green and the bran in a tub and mix thoroughly 

 while dry. Dissolve the syrup in the water and mix this with 

 the poisoned bran, stirring thoroughly. To make the mixture 

 more attractive to many insects, especially grasshoppers, it is 

 flavored with oranges or lemons. This requires three oranges or 

 lemons. They are chopped into fine bits and the chopped fruits, 

 juice and all, are added to the mash above and stirred in thoroughly. 



