THE MONTHLY BULLETIN. 359 



The almond mite should not be dismissed without some discussion of 

 the dusting method of control, for very marked benefit has been 

 obtained by the use of dry sulphur. 



Some kind of a blowing machine is needed for this work, and it is 

 best to use a mixture of hydrated or fine lime dust as a diluent for the 

 sulphur. The first dusting should be applied early in the spring, 

 shortly after blossoming, this to be followed in three to four weeks by a 

 second application ; more dustings to be applied if it proves necessary. 



The Yellow Mite. 



The year following the experiments with the almond red spider 

 (1904), I applied the sulphur-flour paste sulfide of soda mixture to 

 hops at Wheatland in an effort to control the yellow mite {Tetranychus 

 hiniaculatus Harvey). This experiment did not prove successful, as it 

 was found the species in question resisted the action of sulphur almost 

 completely. This resistance is so marked that the mite can develop 

 when foliage, well covered with sulphur, was enclosed in paper bags 

 and exposed to the high temperature of that localit5^ 



Some years later (1911), W. B. Parker, agent, engaged in truck crop 

 and stored products insect investigation, Bureau of Entomology, U. S. 

 Department of Agriculture, was more successful in the control of this 

 mite by the use of a dilute lime-sulphur solution containing flour paste. 

 In this case the paste was used to increase the covering or wetting 

 power of the spray. The killing with this mixture is entirely a matter 

 of contact, and the application may require repeating two or three 

 times for continued control. 



It appears then that a double advantage has been demonstrated for 

 the use of flour paste in spray materials intended for the control of 

 mites; not only may particles of solid sulphur be made to adhere 

 firmly to the foliage, but the wetting power of the spray will be greatly 

 increased. 



Natural Control of Red Spicier. 



Most species of mites (especially the citrus and almond red spiders) 

 are subject to very marked and rapid reduction in abundance as a 

 result of natural causes, including predaceous insects, parasites, and 

 climatic conditions. It frequently happens that the man who sprays 

 his orchard at the time Mdien the red spider attacks look the worst, will 

 not come out much better than his neighbor, who does nothing. Such 

 experience should not, however, be taken as an argument in favor of the 

 do-nothing policy, but on the other hand, they do argue strongly in 

 favor of timing the treatment so as to have preventive effect; that is, 

 spraying before the mites have become numerous, in order to prevent 

 them from becoming so. 



Spray Formulas. 



The original flour paste-sulphur formula is prepared as follows: 

 Mix wheat flour with water at the rate of one pound to the gallon, and 

 heat to the boiling point. The paste so formed will be quite free from 



