UNITED STATES DEPARTMENT OF AGRICULTURE 
| BULLETIN No. 1035 f 
Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 
Washington, D. C. 
PROFESSIONAL PAPER 
February 17, 1922 
THE RED SPIDER ON THE AVOCADO. 
By G. F. Moznette, Assistant Entomologist. Tropical and Subtropical Fruit 
Insect Investigations. 
CONTENTS. 
Page. 
Introduction 1 
Economic importance 1 
Nature of injury to foliage 2 
Food plants and distribution 2 
Description and habits 4 
Biological data 7 
Page. 
Predatory enemies i 
Spraying experiments 11 
Spray rod versus spray gun 13 
Cultural methods in the grove 14 
Recommendations 15 
INTRODUCTION. 
The red spider Tetr any elms yothersi McG. is one of the fore- 
most enemies of the avocado and attacks a number of other plants 
and fruit trees in Florida. It was recognized by avocado growers 
as an important enemy of this.fruit as early as 1909. and since that 
time the damage caused by it has become more pronounced each 
year. This bulletin records the work with this spider during the 
years 1918 and 1919 and the results of cooperative spraying experi- 
ments in connection with the station established by the Bureau of 
Entomology in 1917 at Miami, Fla., for the investigation of various 
insect enemies of the avocado and other subtropical fruits character- 
istic of that region. 
ECONOMIC IMPORTANCE. 
In groves where the red spider is abundant the trees frequently 
become defoliated prematurely during the winter season. This 
generally results in an abnormal development of bloom the following 
spring and the weakened trees are unable to set and hold a full crop 
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