THE CAMPHOR THRIPS. 5 



reared on camphor in cages did not change their appearance or habits 

 in any way. The conclusion may therefore be drawn that the 

 camphor thrips has originated from another source. Since it does 

 not occur on any of the native trees of the family Lauraceae, it, 

 in all probability, must be an introduced species. No evidence, 

 however, has been obtained of its presence in any of the countries 

 where camphor trees are indigenous. The specimens received by 

 Watson from Ceylon and reported (-5) as Cryptothrips fioridensis 

 have since been determined as a different species. 



NATURE AND EXTENT OF INJURY. 



The injury from the camphor thrips seems to be confined almost 

 entirely to pruned trees or trees previously injured from other causes. 



Fig. 3.— A 40-year-old camphor tree, showing magnificent size which these trees can attain when unin- 

 jured by pruning or thrips. 



When grown as an ornamental or shade tree and not cut back, the 

 camphor tree is very luxuriant and often attains great size. While 

 the thrips can often be found on such trees, they have never been 

 seen in large numbers or been known to do any appreciable damage 

 to such trees. Many beautiful specimens of the camphor tree can 

 be found over the State in regions where thrips occur and are even 

 abundant on pruned trees. The tree illustrated in Figure 1 is growing 

 on the camphor farm at Satsuma near the fields in which the thrips 

 have been most injurious. Figure 3 illustrates one of the largest 

 camphor trees in the State. This tree, planted in 1880, now has a 

 circumference of 16 feet 3 inches, with an average spread of 60 feet 

 and a height also of 60 feet. Throughout its growth it has been 

 F^omparatively free from any pests which have unduly interfered 

 with its development. Camphor trees have also proved valuable as 

 windbreaks for citrus groves and when planted as hedges and allowed 



