24 



Mr. Harrison Johnson, of the Cayey-Caguas Tobacco Co., has 

 the following to say x in regard to the use of the Paris green and 

 flour mixture in tobacco plantings : 



I can give no definite figures, but in my opinion the success of a seed bed 

 where this remedy is used is insured fully 50 per cent over another handled 

 under old methods. This application enables the grower to plan for seed plants 

 at a specified time, which is extremely vital to him, owing to the limited 

 period available for planting. The application of flour-Paris green in the fields 

 has likewise proven a blessing for a great many reasons ; the percentage of loss 

 is considerably less than when the mamey leaf was used, and the free seedling 

 starts off unhampered at once; a more even stand is obtained, and the poison 

 will undoubtedly reduce the changa population in the immediate fields very 

 materially. The changa is no longer the menace to the tobacco planter who 

 will avail himself of this proven remedy. 



Experiments have failed to demonstrate any increased effectiveness 

 for baits containing salt, citrus juice, molasses, or honey. A distinct 

 objection to the use of sweetening substances is that they make the 

 bait very attractive to ants, which soon carry the material away. 

 Fowls and domestic animals, of course, should be kept from access to 

 poisoned mixtures. 



GENERAL REMARKS ON CONTROL MEASURES. 



The changa is by no means impossible of control, even though the 

 problem at times is discouraging to the general gardener. The use 

 of poison baits, either alone or in conjunction with such measures 

 as trapping or perhaps flooding, should make crop raising possible 

 even in the most heavily infested areas. Vigorous remedial measures 

 employed year after year in some of the tobacco districts have re- 

 sulted in rendering unimportant what was once a most threatening 

 enemy of tobacco seed beds. Similar results can be obtained with 

 other crops, but it should be borne in mind that control measures 

 must be consistently continued to prevent reinfestation. Probably it 

 will always be necessary to employ artificial means against the 

 changa in Porto Rico, and though the insect can never be stamped 

 out completely, it may be controlled by the exercise of vigilance and 

 energy. 



SUMMARY. 



(1) The changa is a native of the West Indies and South America, 

 but does its greatest damage in Porto Rico. It is the principal insect 

 enemy of general agriculture in the island. 



(2) The insect feeds on almost any tender vegetable growth, usu- 

 ally attacking the plant at the crown just beneath the surface of the 

 soil. It also does much damage by cutting roots that lie along its 

 paths. 



1 In correspondence. 



