CONTROL OF CODLING MOTH IN COLORADO. 29 
SUMMARY OF RESULTS. 
The principal points of interest in connection with the experi- 
mental spray work in the Grand Valley of Colorado may be briefly 
summarized as follows: 
SEASON oF 1915. 
The highest percentage of fruit free from worms obtained in the 
experimental plats in 1915 was 72.22, in a plat which received six 
applications of arsenate of lead paste, 2 pounds to 50 gallons. In 
the unsprayed plat there was but 13.51 per cent of worm-free fruit. 
Arsenate of lime, both homemade and commercial, gave poorer 
control than arsenate of lead. In the control of larve that attempt 
to enter the fruit by way of the calyx cavity the results indicate that 
a low-pressure fine mist spray is as effective as a high-pressure coarse 
spray. The number of stings per apple was considerably less in the 
unsprayed than in the sprayed fruit. 
SEASON OF 1916. 
The best result during the season of 1916, 89.7 per cent of the fruit 
free from worm infestation, was obtained in a plat sprayed four times 
with arsenate of lead powder, 1 pound to 50 gallons. In the unsprayed 
plat 30.98 per cent of the fruit was uninfested. The primary object 
of the season’s work was to test a coarse spray applied by means of a 
short rod equipped with a Bordeaux nozzle in comparison with a fine 
spray apphed with spray poles and whirlpool-disk type nozzles. The 
results indicate that better control was secured with the finer sprays 
applied with the spray poles. 
SEASON oF 1917. 
The highest percentage of fruit free from worms in 1917 was 78.06, 
as a result of six applications of arsenate of lead, 1 pound of the 
powder to 50 gallons of water, to which fish-oil soap was added at 
the rate of 2 pounds to 50 gallons. Two unsprayed plats yielded 
8.83 and 8.54 per cent of fruit free from worms. Another plat 
sprayed with six applications of arsenate of lead, but without fish-oil 
soap, produced 62.10 per cent of worm-free fruit, thus indicating 
that the addition of a soap spreader was of some value. The results 
with the codling-moth trap did not indicate that it materially aided 
in the control of the codling moth during the time of the experiments. 
Nicotine sulphate gave poor control and in combination with arsenate 
of lead apparently had very little value in reducing worm infestation 
or sting injury. Arsenate of lime gave unsatisfactory results. The 
dust treatments were even more ineffective. The plat in which the 
calyx spray was omitted was heavily infested at the calyx end. 
Five spray applications produced practically as much good fruit as 
seven. 
