THE RED SPIDER 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 operation using sulphur dust against the red spider 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 
wet with dew. Where an avocado grower has a large acreage and 
the red spider 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 
