8 BULLETIX 992, U. S. DEPARTMENT OE AGRICULTURE. 
ripe. The Rush grove, however, was kept under close observation 
by Mr. Rush and the writer. The flies became very numerous on the 
trees of this grove for a period of a few days after the spray was 
applied and then decreased in numbers. 
Examination and counts of the nuts of the sprayed trees in the 
Baile grove just before the crop was gathered showed that 4 per 
cent of the nuts had been attacked by the maggots, whereas at least 
60 per cent of the crop had been destroyed by the maggots the pre- 
vious year. In the Rush grove it was estimated that the condition 
was 75 per cent better than the year before when no treatment was 
given. Xo Persian walnut trees were found near either the Baile or 
Rush groves that were suitable for use in checking up definite results 
of the spraying. However, a comparison of the sprayed nuts with 
those produced by the same trees the previous season and with those 
produced in other localities the same season, together with the known 
abundance of the flies that appeared early upon the sprayed trees, 
indicates decidedly beneficial results from the treatment. 
Flies confined in roomy wire-screen cages were observed to feed 
freely on sweetened water to which sufficient lead arsenate had been 
added to give the liquid a milky color. It must be admitted that 
these flies succumbed very slowly to the poison. Further tests of 
this treatment must be made before it can be recommended unre- 
servedly as an effective and sure method of control for this pest. 
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