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MONTHLY LETTER OF THE BUREAU OF ENTOMOLO YY 
UNITED STATES DEPARTMENT OF AGRICULTURE," ° | | soa 
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Number 220 Activities for July August, 1932 
(Not for Publication) anisanascesscrsnc | 
DOCTOR HOWARD COMING HOWE 
Dr. L. 0. Howard, who has spent the past year in Paris, France, 
plans to embark on the steamship Minnewaska at Havre on October 1. He 
expects to arrive at New York on October 10 and to be in Washington on 
October 11. His address after September 15 will be the Bureau of Ento— 
mology, U. S. Department of Agriculture. 
GEORGE W. ELLINGTON 
On August 23, 1932, while engaged in experiments on liberating hy— 
drocyanic acid gas from a single generator, George W. Ellington was over— 
come by gas and died before he could be carried into the oren air. 
These experiments were carried on in a residence in Takcma Park, Nd., 
and were designed to obtain information on the diffusion of the gas from 
@ Single point and its effectiveness in the control of clothes moths and 
cockroaches. 
Mr. Ellington's untimely death is deeply regretted. He was an ac- 
Sistant entomologist and during his ten years' association with the Bu- 
reau of Entomology has been connected with the Division of Stored Pred 
uct Insects. During this pericd he was concerned in important investi- 
gations of grain insects and assisted in many fumigations. In additicn 
to this, he had recently carried on experiments (the subject of a note 
in this number) to determine the effectiveness of paradichlorcbenzene 
in disinfecting seeds. 
FRUIT AND SHADE TREE INSECTS 
Relation between citrus rust mites and sulphur resicve.-- "Rust— 
mite counts made twice during the past month" by W. W. Yothers and R. 
L. Miller, Orlando, Fla., "show that there is a very definite relation 
existing between the quantity of sulphur residue left on citrus leaves 
from spraying or dusting and the number of mites present. Apparently, 
when there is less than .05 gram of sulrhur on one kilogram of green 
leaves, rust mites are able to establish themselves. Lime sulphur (1- 
to-50) when used with kaolin or iron sulphate and colloidal sulphur (3 
pounds to 100 gallons) have shown the most sulphur present by residue 
analysis and have had the fewest rust mites present. Lime sulrhur (1- 
to-50). used alone was slightly better than when calcium caceinate, glue, 
or gum arabic were used with it. When dried blocd or gum tragacanih 
w:S mixed with lime sulphur the results were the same as when lime 
sulphur alone was used." 
