a 


Dayar 
heavily infested with purple scales were attached to 50 of the sprayed 
leaves by means of paper clips. Two months afterward all the leaves to 
_ which infested leaves had been fastened were picked and the dead and liv— 
ing purple scales present were counted. The results are shown in the 
following table: 


Lime-sul-— Sulphur residue per kilo- Average is 
phur con— gram of leaves Leaves Scales Living scales 
centration 10/29 12/29 Average counted counted Scales per leaf 
: Grams Grams Grams Number Number Percent Number 
a z-66 0.48 LO 20 3504 13.4 oO 
BOs... ...... 1.46 .93 208 20 135 28.0 ing 
POO )c:......... 1,35 .32 .83 20 186 51.0 4.7 
mneck....,... _- -— -— 20 166 76.0 6.6 
LT Rt SR tL ee a ny er a 

ee es ee a er ee rt A 
fron-oxide and lead-oxide dust effective against the citrus rust 
mite.—-W. W. Yothers and associates at Orlando report further on the use 
Of iron oxide in the control of Phyllocoptes oleivorus Ashm.: "Leaves 
dusted with iron oxide and lead oxide were brought into the laboratory 
and other leaves heavily infested with rust mites were attached to then. 
At the end of two days when the infested leaves had wilted, the number of 
mites on the dusted leaves were counted, 25 half-inch circles being 
counted on the upper and 25 on the lower surfaces of each plot. * * * 
When the mites were examined under the microscope with the oxide on them 
it was found that none were able to retain their hold on the leaf. They 
held to the oxide particles and when these particles fell from the leaf, 
the mites fell with them. Another experiment was tried in which the iron 
oxide was sprayed on as iron hydroxide and in this case it stuck tight to 
the leaves like varnish. When mites were introduced on this they were 
able to remain as shown below: 


eee es —~ 

a 

Circles Mites Average mites 
counted present per half-inch 
circle 
Number Number . Number 
Iron oxide, smooth on leaf........ Al ne 0.53 
a ne 44 Re 50 

These results indicate that the effect of iron oxide in controlling 
mites is entirely mechanical. When the iron-oxide particles are loose 
and roll off easily they carry the rust mites with them, and when the 
iron sticks tight the mites are able to establish themselves." 
JAPANESE BEETLE AND ASIATIC BEETLE RESEARCH 
Paradichlorobenzene as a soil fumigant for Jap beetle.——-Reporting 
on experiments to determine the value of paradichlorobenzene for the de- 
struction of immature stages of the Japanese beetle in the soil about 
the roots of balled nursery stock and potted plants, J. W. Lipp, Moores-— 
town, N.J., says: "Dormant roots of several varieties of perennials, 
