470 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 14 



The two scales are quite widely distributed, being found on both the 

 east and west coasts of southern Florida. In Florida the Mango Shield 

 Scale has been found on them.ango, roseapple, custard apple, sapodilla 

 and Allamanda. It is also found in Grenada, Barbados, Dominica, 

 Antigua, Trinidad, Jamaica, and British Guiana where it infests in 

 addition to the host plants mentioned in Florida the breadfruit, Jas- 

 minum, Ixora, star plum, star apple and the nutm.eg. The Tessellated 

 Scale has been found to infest the mango, cocoanut and roseapple in 

 Florida. In the West Indies it also infests Caryota urens and m.any 

 other palms. 



Both of these scale insects produce an abundance of honeydexv. 

 The sooty m,old fungus develops in this honeydew deposit, giving the 

 mango tree in the course of tim.e a decidedly blackened appearance. 

 The sooty m.old often collects on the fruit as well as the foliage, giving 

 the fruit a blackened and unsightly aj)pearance. The writer has observ- 

 ed several groves where the sooty mold was so nxmierous that even 

 the branches and trunks of the trees were blackened by it. 



Results Obtained with Insecticides 



In testing out the following insecticides, badly infested trees were 

 selected averaging from twelve to fourteen j^ears of age with an average 

 heighth of from twenty -five to thirty-five feet. In each case the spray 

 was directed toward the lower surface of the foliage, using a spray gun 

 with a pressure of from 225 to 250 pounds. 



Lime Sulphur Solution 



In applying this insecticide to the m.ango at a strength of one gallon 

 of lim.e sulphur solution to forty gallons of water in December while 

 the trees were dormant and again in March at a strength of one gallon of 

 lime sulphur solution to fifty gallons of water, it was found, that it did 

 not effectively destroy the scales. The spray killed about 50% of the 

 scales present on the trees, and did not remove the sooty mold present. 

 Due to the tenderness of the mango foliage it was found that the strength 

 of the spray could not be increased. 



Caustic Potash Fish Oil Soap 



This insecticide was applied to the mango at the same time and 

 interval as the above spray at a strength of twenty pounds of caustic 

 potash fish oil soap to one hundred and twenty-five gallons of water. 

 The same strength was used during both applications. The results 



