74 SOME INSECTS INJURIOUS TO TRUCK CROPS. 
impoverished in vitality and the growth thereby seriously retarded. We were 
troubled with them last year [1905], but not to the same extent, and had them 
till after hop picking. In the middle of July they were so numerous that the 
ground was fairly alive with them. They go into the ground in the evening 
and come out again in the morning, and there has been no spray found to have 
any effect without killing the plant. 
Substantially the same form of injury was reported during the 
same year at Agassiz, B. C, by Mr. John Wilson in a letter to Doctor 
Fletcher. Writing September 7, 1906, Doctor Fletcher stated that 
this species had been enormously destructive in British Columbia, 
one correspondent reporting the loss of many thousands of dollars. 
He estimated his crop as possibly TO bales, whereas he should have 
had 250. 
Writing of this species, January 30, 1907, Dr. E. D. Ball, while 
working in cooperation with the writer, stated that it was by far the 
most injurious species on sugar beet in Utah. It was found every- 
where and was apparently the most common species in early spring. 
It was observed hibernating around the edges of fields, in patches of 
dead mustard, along ditch banks, and in similar places. Where 
ditches were covered with patches of roses these seemed to furnish a 
favorite retreat. These clumps grew to a height of 2 or 3 feet and 
were very dense, and from them one could see the injury to the beets 
radiating in every direction, the affected area growing wider and 
wider as time went on. In early spring this species fed on almost 
anything that came to hand, but its injury to beets was practically 
all done at the time the plants were first appearing through the 
ground or within a few days thereafter. Cases were observed where 
the rows of young plants could be seen the entire length of the field 
one clay, and two clays later scarcely a beet plant could be found, the 
beetles having eaten the tender stem, causing the tops to fall off and 
the beets to die. Frequently they attacked beets just as the latter 
were pushing through the ground. Hundreds of acres had been 
destroyed in this way, injury varying greatly in different years and 
in different localities. 
Great damage was done near Logan, Utah, where the hedge mus- 
tard was overrunning the fields. At Lewiston, Utah, at the northern 
end of the same valley, injury was also severe, although there was 
little of the common black mustard. 
The destruction of a crop by this species does not necessarily entail 
a complete loss, as the growers replant. The late plants, however, 
are not, as a rule, as good as the earlier ones, and the weeds get such a 
start that the land is hard to cultivate. After the beets had reached 
a leaf diameter of 3 or 4 inches no material injury was noticed, 
although the beetles continued to appear in the fields throughout the 
season. Beetles were observed July 20, 1906, at Cache Junction, 
