76 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Yol. 11 
beetle, which was supposed to be one of the chief factors in the dis¬ 
semination of this disease. Bordeaux mixture 2-4-50, with lead arse- 
Jnafte paste 4-50, was applied to all cucurbits in an isolated area. 
Eleven acres were treated every 7 to 10 days during the first half of 
Ihe season. The beetles were extremely abundant. 
It soon became apparent that the control of the beetle was far from 
perfect, and we could notice no lessening of the destructive mosaic 
‘disease. A number of experiments were then started, with the pur¬ 
pose of obtaining definite data on the efficiency of the spray. Some 
insecticides which had been tried in a small way in the field, and which 
showed no injury to the plants, were also included. The results were 
checked during the past season. 
To ascertain the percent efficiency of the Bordeaux-lead arsenate 
in the field, a number of beetles were collected from young squash 
plants immediately before spraying for the first time and twenty- 
four hours later. After ten days, 10 of 102 beetles collected before 
spraying had died, while 25 of 93 beetles collected after spraying had 
died. The per cent mortality of each was respectively 10.8 and 36.77, 
or about 26 per cent efficiency of the spray. This was surprising, for 
Bordeaux-lead-arsenate had been recommended for the control of 
the striped cucumber beetle. 
A series of tests were then conducted in large cages, wooden frames 
and cloth top and sides, the latter with sleeves for head and arms to 
make handling convenient and eliminate losses. The cages were 
placed over single plants in the field, and a heavy muslin cloth was 
sewed about the stem of the plant and tacked to the sides of the cage 
to prevent the beetles from burrowing in the soil. A small compressed 
air atomizer, capacity one quart, was used in the spraying. It was 
aimed to cover the plants completely, a practice hardly possible under 
field conditions. All blossoms were plucked because of the avidity of 
the species for flowers, which could not be sprayed thoroughly. The 
beetles were left on the sprayed plants for twenty-four hours unless 
otherwise noted, and were then removed to Riley cages and observed 
daily for five days. Each cage contained 100 beetles and a check 
was run with each experiment. The beetles were collected from un¬ 
treated fields. In most instances the living and dead beetles were 
counted when removed from the plants, and again at the close of the 
experiment. Table I gives the results of the experiments carried on 
in 1916. 
In 1917 two experiments were performed in a similar manner but 
new cages of special construction were used and the losses of the 
active beetles in handling were greatly reduced. The cages were con¬ 
structed as follows: a frame 2 feet wide, 2 feet high, and 3 feet long 
