LOSSES FROM SCALE INSECTS PREVENTED. 



61 



grapefruit. All of the grapefruit and 300 boxes of the oranges were 

 scraped by hand to remove the scale. This operation cost between $275 

 and $300. The loss to the selHng value of the oranges was about $225 

 and of the grapefruit about $1 ,000. Many instances have come to the 

 writer's attention of losses from scale amounting to 5 per cent of the total 

 value of the crop. In addition to direct losses of the Idnd noted above, 

 frecjuently more serious losses are suffered as a result of the complete 

 destruction of branches and weakening of the vitality of the trees by 

 the heavy incrustations of the scales upon the main branches or 

 trunks. The total damage from scales in Florida is usually too 

 small to make direct remedial measures profitable, but when tliis 

 damage can be to a large' extent obviated at the same time with that 

 of the white fly, the mat- 

 ter demands careful con- 

 sideration. It is the 

 writer's conviction that 

 in the cases of the ma- 

 jority of groves the de- 

 struction of the purple, 

 long, Florida red, and 

 other scale insects would 

 represent an increase 

 in profit wdiich would 

 by itself offset the cost 

 of fumigation, leaving 

 as clear gain the ben- 

 efits derived from redu- 

 cing the numbers of the 

 wliite fly to a negligible 

 quantity. 



The Florida red scale 

 {Cliry sotn plialus ficus Ashm.) (fig. 10) is destroyed with a thorough- 

 ness near to absolute extermination by the same dosage which is 

 rec^uired for the white fly. This has been conclusively proved by the 

 experimental work conducted by the writer antl Mr. W. W. Yothers 

 in January of the present year. Not infrequently in Florida the scale 

 insect referred to causes sufficient injury to make fumigation a very 

 i:)rofitable procedure against this insect alone, lea\'ing out of consid- 

 eration the effect upon the other pests present. 



The purple scale {Lepidosaphes heckii Newm.) (fig. 11) sometimes 

 called the ''brown," "oyster-shell," or "hard" scale, is of greater eco- 

 nomic importance than the Florida red scale on account of its more 

 wide-spread distribution. The results in controlling this pest accom- 

 plished incidentally to work against the white fly are most encouraging. 

 In the same grove where the effect of fumigation on the Florida red 

 scale was observed, the purple scale has been so abundant for years 



Fig. 10.— Florida red scale ( Chrysomphalus ficus) : a, Leaves 

 covered with the male and female scales, natural size; b, newly 

 hatched insect with enlargements of antenna and leg; c, d, e, f, 

 different stages in the development of the female insect, drawn 

 to the same scale; g, adult male scale, similarly enlarged. 

 (After Marlatt.) 



