SPRAVIXG FOE CITRUS IXSECTS AXD MITES IX FLORIDA. 



33 



The bulplmr sprays are very effective, also, in killing the purple 

 and six-spotted mites. The killing action is rapid, but the bodies 

 are not completely destroyed by the caustic nature of the spray as 

 is the case with rust mites. The spray does not prevent the eggs 

 from hatching, but the presence of the spray usually kills the young- 

 mite as soon as it emerges | ^ 



from its eggshell. Thou- 

 sands of newly hatched 

 dead mites have been ob- 

 served near the eggshell 

 from which they had just 

 emerged. While the oil 

 sprays usually prevent an 

 egg from hatching, the 

 sulphur sprays more often 

 kill the young " crawler " 

 as soon as it hatches. 



Sulphur when used in a 

 fine state with hydrated 

 lime also kills six-spotted 

 and rust mites. When six- 

 spotted mites come in con- 

 tact with fine sulphur they 

 become exceedingly active 

 at first, run about in a per- 

 fectly wild and aimless 

 manner, then gradually 

 become quiet, and finally 

 die. All mites, so far as 

 known, are extremely sen- 

 sitive to sulphur in any 

 form. 



SPRAY INJURIES. 



Under average condi- 

 tions of temperature and 

 moisture the oil sprays 

 will not cause any notice- 

 able injury to either the 

 foliage or the fruit. Xew 



Fn;. 22. Pupae of the citrus white fly. Wheii 

 living the pupae are seen with difficulty, but after 

 they have been killed, as in the illustration, they 

 turn brown and one can then easily see how thin 

 and scalelike they really are. (Morrill and 

 Back.) 



growth often starts in a few days after the killing of the in- 

 sects. A large percentage of old leaves, now functionless, fall 

 about the third day following the application of an oil spray. Good 

 leaves very seldom fall. In the experiments 2 per cent of oil, 



