field experiments in destkoying weevil. 29 
Cultivation in Connection with Irrigation. 
For an experiment to determine the value of cultivation in connec- 
tion with irrigation in controlling the alfalfa weevil a field was selected 
on a farm belonging to Mr. Hansen, 1 mile southeast of Sandy, 
Utah, containing 16 acres. The soil was a light sandy loam. Some 
of the weevils had been noticed in this field in 1908 and also in 1909, 
while the first crop of 1910 was severely damaged and the second also 
suffered considerable loss. May 11, 1911, the field was irrigated, the 
infestation being considered heaA^y. The first crop was cut during 
the week ending June 10. The plants were about 9 or 10 inches high 
and the hay yielded less than 1 ton per acre of very poor quality. 
This field was again irrigated and the more elevated portion of it 
worked with a spring-tooth harrow while the surface was still soft 
from the irrigation. This treatment was repeated and when finished 
the field had very much the appearance of any cultivated field, 
little resembling a meadow. (See PI. VIII, fig. 1.) 
On June 22, while the land was still soft and muddy, a light irriga- 
tion was given it, so that the water collecting in the lower portion of 
the field stood to a depth of 2 or 3 inches. Four horses were hitched 
to a plank leveler and dragged through this mud, as shown in Plate 
VIII, figure 2. This thoroughly ^ Spuddled" the weevil in all of its 
stages beneath the surface. 
By the 30th of June a second crop was starting very nicely while 
neighboring untreated fields were being retarded by the continued 
attacks of the weevil. Ten days later the plants were about 12 
inches high with very few of either larvae or beetles present. How- 
ever, a patch had been left uncut and unworked in one corner of this 
field and here the first crop of alfalfa was still standing. (See PL 
IX, fig. 3, at the right.) 
There were a great many larvae and beetles on this patch, which 
disseminated themselves into the growing alfalfa where the mudding 
process had been practiced, destroying a strip about 1 rod in width, 
clearly shown in Plate IX, figure 3. The second crop in this field, 
July 10, 18 days after the mudding experiment was carried out, was 
about 14 inches high. (See PL IX, fig. 1.) 
In a near-by untreated field at the same time, four weeks after the 
first cutting was made, the condition is shown in Plate IX, figure 2. 
Burning Machine. 
Several field experiments were carried out with a machine con- 
structed with the idea of burning over alfalfa fields after the removal 
of the first crop for the purpose of destroying the weevils in any stage 
of development remaining in the field. The machine, as shown in 
Plate X, figure 1, consisted of an iron frame 9 feet square, 12 inches 
