CACTUS SOLUTION AS AJST ADHESIVE. 17 



SUPERIORITY OF CACTUS FROM DRY LAND. 



It has been found that cactus growing near resacas and in low 

 wet places yields less glutinous matter to the gross pound than it 

 does when growing on high dry soil. Thus time is saved in making 

 up a spraying solution if the cacti are collected from the higher re- 

 gions, and not in or near standing water. 



On April 13, 1914, 75 pounds of cactus were placed in 40 gallons of 

 water. Twenty-four hours later the cactus was removed and al- 

 lowed to drain for about one-half hour. It weighed 85.5 pounds, 

 or 10-J pounds more than when placed in the water. Another lot of 

 110 pounds was increased in weight to 124 pounds by leaving it 

 in water 24 hours. However, when the cactus is sliced and allowed 

 to remain in water until fermentation is well under way, there will 

 be a slight decrease in weight. This will not happen where a pre- 

 servative is used. 



ADVANTAGES IN THE USE OF CACTUS AS AN ADHESIVE. 



By the use of cactus as an adhesive not only do the arsenicals 

 give better and more lasting results, but considerable expense may 

 be saved in another way. In the Southwest, where all insecticide 

 material must be shipped in from a great distance, the expense of 

 transporting this material is often more than the cost of the in- 

 secticide itself, so that material of a poor quality is often used in- 

 stead. For some years arsenicals in the paste form have been exten- 

 sively used by fruit and truck growers on account of their better 

 adherence and lasting qualities, but where a good adhesive is used 

 the writer much prefers arsenicals in the powder form. In conduct- 

 ing experiments in the insectary and in the field at no time have 

 the powdered arsenicals proved less effective, and at times the mor- 

 tality would be considerably above that shown in another experiment 

 conducted at the same time with arsenicals in the paste form. Better 

 results have been obtained in using 1 pound of zinc arsenite in pow- 

 der form with cactus than by the use of 3 pounds in the paste form 

 to the same amount of water. Thus equal results may be. obtained, 

 with a reduction of 66 per cent in express and freight charges paid 

 in securing arsenicals from a distance. 



QUANTITY OF CACTUS TO USE. 



The amount of cactus that may be used with good results varies 

 with the environment under which the plants have been growing. 

 If the plants have been growing in or near water it will be neces- 

 sary to increase the quantity of cactus used to each gallon of water. 

 In general, the correct proportion will range from ^ pound to 1 



