372 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 4 



in the highest state of productiveness should welcome the assistance 

 and cooperation which such a law would provide. These growers 

 usually need protection from neighboring citrus groves whose owners 

 are alsent, leaving incompetent men in charge, or whose owners for 

 other reasons are indifferent or would fail to cooperate in whitefly con- 

 trol except under compulsion. Even in such cases, however, the law 

 would operate to advantage since, if the owner failed to take action 

 when directed to do so, treatment by spraying or fumigation would be 

 done by the county, the owner would be compelled to pay for the work 

 and incidentally find it necessary to profit by the control of the insects. 



When citrus groves or trees are of so little value as not to justify 

 the expenditures necessary to whitefiy control, the complete destruc- 

 tion of the trees is advisable and will naturally follow the administra- 

 tion of the law. There are today in f lorida thousands of citrus trees 

 which are a detriment to the citrus industry of the state; trees which are 

 unproductive and which occupy space which could be more profitably 

 used l)y the owners. In other cases growers are financially unable 

 to control the whitefiy owing to their holdings being too extensive. 

 In such a case the enforcement of a law requiring the control of the 

 whitefiy, necessitating the disposal of a portion of the grove concerned, 

 would be an actual benefit to the owner as well as to the community 

 interests. In many cases one half the acreage now under one owner- 

 ship, better cared for culturally and with the insect pests brought 

 under control would yield a net profit as large or much larger than the 

 entire property under the present conditions. 



Still further changes are demanded and would naturally follow the 

 operation of a horticultural law with advantage to all concerned. 

 The control of many insect pests has made necessary extensive changes 

 in farm and orchard practices. Frequently the changes in the methods 

 of culture developed by an entomological investigation are in the main 

 changes which would be of advantage even if adopted before the appear- 

 ance of the insect pest concerned. This is the case with the whiteflies 

 which attack citrus trees in Florida.^ Much has been accomplished 

 in the last few years in the adaptation of fumigation and spraying to 

 whitefiy control under Florida conditions, but radical measures are fre- 

 quently required to place the use of these direct remedies upon the 

 most practicable and profitable basis. These measures consist in reduc- 

 ing the height of citrus trees, when excessive, and in reducing the num- 

 ber of trees to the acre when they are so closely planted as to interfere 

 with control measures. In the opinion of the writer the height of 

 citrus trees wherever the citrus or cloudy winged whiteflies occur 

 should not exceed twenty-five feet. The branches of adjacent trees 



aBuI. 76, Bur. Ent. U. S. Dept. Agric, p. 14; Circular 111, p. 10-11. 



