INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



473 



way. Dusts are easy to mix and handle and are often of great service 

 to the farmer and orchardist. 



FLOWERS OF SULPHUR 



For a number of years flowers of sulphur was used alone as a remedy 

 for mites on citrus and almond trees. It was distributed over the 

 trees by hand or with a blower in the early morning when the foliage 

 was damp, thus enabling it to adhere. The warm sunshine volatilizes 

 some of the sulphur and oxidizes a part so as to liberate two gases, 

 which are killing factors. Accordingly sulphur is of little avail in 

 the cool summer weather of the coast counties or during the winter 

 months anywhere. However, in the warm interior districts this is 

 still a very effective remedy for mites. 



Fig. 475.- — A power blower for applying dusts in orchards. 

 About forty acres can be treated in one day with such a 

 machine. 



SULPHUR AND LIME 

 Even better than sulphur alone is hydrated lime and flowers of 

 sulphur mixed in equal parts and blown upon the trees with a p<y 

 machine, as is shown in Fig. 475. In the citrus orchards this is a very 

 important method of controlling the citrus red spider (Tetranychus 

 mytilaspidis) and the two-spotted mite (Tetranychus telarius). 



