364 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 4 



million dollars per year.^ In two counties in Florida (Manatee and 

 Orange) the losses from whiteflies amount to fully two hundred thou- 

 sand dollars each per year and in several others it amounts to more than 

 one hundred thousand dollars per year. With losses such as these, 

 usually representing in infested groves between one third and one half 

 the value of a crop, practically all business interests in important 

 citrus fruit producing localities are vitally concerned. Bankers and 

 merchants for example, even though not owners of citrus groves, 

 are in many localities in Florida fully as much dependent in a business 

 way on the citrus fruit crops as is the average grower. It is a note- 

 worthy fact, moreover, that in many important business centers in 

 Florida, such as Orlando, Bartow and Fort Myers a large percentage 

 of the bankers, merchants and professional men are grove owners or 

 part owners and are consequently doubly interested in the success of 

 the citrus industry. 



The first point for consideration in connection with suitable legis- 

 lative enactments is the extent to which expenditures by state or 

 county are justified. According to the estimates of the writer, the 

 expense of a suitable supervisory organization would be insignificant 

 beside the direct benefits that would result and moreover would be 

 fully compensated for by the incidental reduction in the amount of 

 injury by scale insects.^ An amount between five and ten per cent 

 of the total losses resulting from whitefly attack on the basis of a forty 

 per cent damage in each infested grove should be ample to cover 

 such expense. In countries or localities where the whiteflies do not 

 exist or where they infest only a small percentage of the citrus groves, 

 not more than one per cent of the gross value of the citrus crop should 

 be necessary for checking the spread of the insects in order to delay 

 to the utmost the time when the infestation in the county or locality 

 will be general. These estimates of the amount, which will be needed 

 for the carrying out of a program of whitefly control supported by 

 legislative enactment, indicate in a general way the necessary expense 

 for different sections. In Florida, the leading citrus fruit growing 

 counties such as Orange, De Soto, Manatee and Polk, would reciuire 

 in the writer's opinion from eight to ten thousand dollars annually 

 for the support of efficient county organizations created in accordance 

 with the provisions of a state law. Other counties in which citrus 

 growing interests are less important would require smaller organi- 



iThe writer estimates that more than four fifths of this loss is caused by the citrus 

 whitefly and less than one fifth by the cloudy winged whitefly. The discussions 

 which follow apply to both species except as affected by the latter species being con- 

 fined to citrus as a food plant. 



^Bul. 76, Bur. Ent., U. S. Dept. Agric, p. 60-62. 



