10 FARMERS’ BULLETIN 741. 
the work on the alfalfa fields need not conflict with either of those 
operations. Aside from its relation to spring spraying, this early 
feeding of the adults is chiefly important in that it gives the spores 
of Sackett’s disease a chance to lodge within the tissues of the plant." 
The damage caused by this blight is sometimes as serious as that 
done by the weevil larvee themselves and is generally confused with it. 
EGG LAYING OF THE WEEVILS IN LATER SPRING. 
After feeding for several weeks, running about over the ground, 
depositing eggs in dry stems, and flying a little, the adults deposit 
large numbers of eggs in living stems. When the spring opens early 
they begin egg laying gradually, and the earliest eggs may hatch 
before the majority are laid. After a late spring the egg laying 
begins abruptly. In either case it is usually ended before June 10, 
and if the eggs can be destroyed up to that date, the attack of the 
larvee will be prevented for the year. This can be done by pastur- 
ing the first crop so as to destroy the eggs after they are laid and 
before they hatch, or, at latest, while the larve are still small enough 
to cling to the leaves and be swallowed. This is the basis of the 
pasturing method and of a similar method of destroying the eggs 
and at the same time utilizing the first crop by cutting the alfalfa 
green and feeding it as a soiling crop. 
WORK OF THE LARV IN THE FIRST CROP OF ALFALFA. 
If none of the treatments mentioned has been used, the larvae ap- 
pear in large numbers about the last week of May, or earlier if the 
spring has been favorable, and eat the leaves, especially on the 
young shoots, so rapidly that the plant is unable to outgrow the 
injury. At this stage, or a little earlier, it is necessary to cut the 
crop regardless of its condition, in order to prevent severe and per- 
haps total loss. The results of spring cultivation show at this time. 
The fields which have been cultivated grow earlier and produce a 
larger yield before cutting becomes necessary than do those which 
have been neglected. A few of the larve have finished feeding 
and spun their cocoons before even an early cutting. Most of the 
others spin during the month of June, though a few late larvee are 
abroad in the field until winter. 
When the first crop is removed, if the ground is dry and the weather 
clear and warm, many larvee, pup», and adults die as a result of 
exposure to the heat of the ground. This mortality is mereased 
if the ground is cultivated in such a way as to fill the cracks, crush 
the clods, and scrape off all remaining vegetation. This, in turn, 
is more easily accomplished if the soil has been kept in good condi- 
tion by manuring and cultivation. The killing of the insects by 
heat is the foundation of the “‘brush-drag’’ treatment. 
10’Gara, P. J. Bacterial blight of alfalfa in Salt Lake Valley. Jn Science, n. s., v. 39, no. 1016, pp. 905, 
906. 1914. 
