THE HAWAIIAN BEET WEBWORM. 9 
September 12, all the larvae which had not matured were still feed- 
ing and showed no ill effects from their diet of arsenate of lead and 
Amaranthus leaves. The spray mixture caused no injury to the 
foliage. 
In this test a standard grade of arsenate of lead was used at the 
rate of 6J pounds in 100 gallons of water, and it is difficult to under- 
stand why it failed to kill the tender Hymenia larva?. Of course, 
such a test as this can not be considered conclusive, but it would indi- 
cate that less effective results would be obtained with arsenate of lead 
than with Paris green. 
Experiment No. 4- — Lime-sulphur solution, 1 gallon, in 15 gallons 
of water. November 1, a few infested beets were sprayed with a small 
quantity of this solution. A thorough application was made to the 
upper surface and underside of the leaves with an atomizer. Larva? 
which were drenched with the solution appeared to die promptly. 
The weather was hot and clear at the time of the application. Two 
days later the larvae had been reduced somewhat in numbers but there 
were still plenty of living specimens present. Some of the leaves 
were severely burned. November 5, the coat of lime was still very 
good. The larvae were feeding on the coated leaves and were appar- 
ently unharmed. This solution apparently killed only the larvae 
which were thoroughly drenched at the time of the application. The 
beet foliage was severely burned, and on the whole the results were 
not promising. 
Experiment No. 5. — Lead chromate, 2 ounces, in 8 gallons of water. 
December 16, a few infested beets were sprayed with a small quan- 
tity of this mixture. The application was made to the upper and 
lower surfaces of the leaves with an atomizer. The mixture ap- 
peared as a yellow coating on the leaves and adhered very well. The 
weather was hot and clear. Three days later the larva? were still 
alive, but had ceased feeding, and were clinging to the leaves in a 
listless manner. During the following two or three days they 
dropped to the ground and died. The sprayed foliage showed no 
burning. It is not possible to form a definite conclusion from this 
meager test, but it indicates that lead chromate at this strength is 
very slow in its killing effects. 
In another similar test lead chromate was used on beets at the 
rate of 2 ounces in 4 gallons of water. L T nfortunately an illness of 
the author prevented the making of observations as to the effect of 
this strength on the larvae. Ten days after the application it was 
noted that two heavy rains had failed to wash the coat of poison 
from the leaves and that no burning had resulted. It is evident 
that this new insecticide has some good points, and it should be 
given a thorough trial. 
