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 ruy 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. 
