THE RED SPIDEE. ON THE AVOCADO. 



11 



on the foliage in search of red spiders. It is not very abundant at 

 any time. 



SPRAYING EXPERIMENTS. 



A number of insecticides have been tried out to ascertain their rela- 

 tive merits against the avocado red spider. The experiments were all 

 conducted cooperatively with growers and in groves where the mite 

 was abundant. 



Fig. 8." 



-Power duster in uyeratiou usiug ^^iilijhui' dust agaiu.st the led i^pider in an 

 avocado grove. 



SULPHUR DUST. 



An impalpable sulphur dust was tested on both the West Indian 

 and Guatemalan races of avocadoes. In applying the material a 

 power duster (fig. 8) was used. The sulphur proved to be very 

 effective against the species, killing 99 per cent of the spiders, and 

 remaining effective on the foliage over as long a period as did any of 

 the liquid sprays tested. Experiments with this material showed that 

 it was not necessary to apply the sulphur dust when the foliage was 

 Avet with dew. ^'\'Tiere an avocado grower has a large acreage and 

 the red spicier is the only serious enemy to contend with, the dusting 

 method is very practical and by far the quicker method. At the 

 present time, however, the avocado grower has other insect pests with 



