The Avocado: Its Insect Enemies. 91 
face of the foliage, and in so doing roll the leaves back from the tip 
(fig. 15). When the larve mature they often construct silken cocoons 
in the folds of the leaf and there pupate. Often where the leaf- 
rollers have been numerous in the spring, the foliage eventually 
presents a very ragged appearance. 
HOW IT MAY BE CONTROLLED. 
Spraying the new growth with pow- 
dered arsenate of lead at the rate of 2 
pounds to 100 gallons of water has proved 
successful in controlling the leaf-roller. 
The spray tank should be fitted with a 
good agitator, as the poison has a tend- 
ency to settle to the bottom if not kept 
constantly stirred. 
THE AVOCADO RED SPIDER AND THE 
a LEAF-INFESTING THRIPS. 
Among the insect pests which attack 
avocado foliage are two which BO gee aie Wt ee aS 
considerable damage during the dry Adult, Greatly enlarsed. 
winter months. These two pests are 
the avocado red spider® and a_ leaf-infesting® thrips, com- 
monly known in the North as the greenhouse thrips, but which 
works on the avocado 
in the open in Flo- 
rida. The red spider 
of the avocado 
(fig. 16) is similar in 
shape and = appear- 
ance to other red 
spiders, its habits 
only varying in that 
it confines its attacks 
to the upper surface 
of the foliage. The 
leaf -infesting thrips 
is similar to most 
Fic. 17.—The avocado leaf-infesting thrips: Adult. other thrips, is dark 
Greatly enlarged. (Drawing by Russell.) 
brown in color, and 
about 1 millimeter (one twenty-fifth inch) in length (fig. 17). 
CHARACTER OF INJURY. 
In Florida it is usually from the latter part of November until 
March that the greatest damage is caused to the avocado by the 
red spider and the leaf thrips. The abundance of either pest 
8 Tetranychus yothersi McG. 
® Heliothrips haemorrhoidalis Bouché. 
