20 



enclosed in the chamber, and not a single egg hatched among tens of 

 thousands exposed. 



Notwithstanding the efficacy of the gas, however, it is quite an 

 impossible task to exterminate the Eed Scale where it has long been 

 established, for not only does the scale infest citrus trees but other 

 orchard trees and many garden plants and even some ornamental 

 trees like the Seringa (Melia azedarach) , Keurboom, Willow, and 

 Cypress. It usually occurs in the greatest abundance on the citrus 

 trees and it is generally from them that the other plants become 

 infested; but when the citrus trees are cleaned, it is but reasonable 

 to suppose that the insect will in time find its way to them from 

 these other trees. Rose bushes are very frequently infested, and as 

 these plants are to be found on almost every farm, the infection is 

 very likely to spread from them to the citrus trees. It may be one 

 year or two years or even longer before the citrus trees become 

 noticeably affected, but sooner or later, the insect is quite sure to get 

 to them and to again require attention. 



The tents and sheets should be examined each day, when all rents- 

 and holes should be covered by patches. A small piece of cloth 

 about holes caused by the acid should be cut away or the acid will 

 continue to destroy the fibre. The fumigation of trees covered by 

 cloth containing holes is very apt to be a complete failure. 



Quantities of Chemicals. The following table gives the 

 quantities of the chemicals used for various sizes of trees by the 

 iumigators for the Horticultural Board. 



