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extremely delicate plants and therefore can be used without dan- 
ger by unskilled labor. 
At the present time “Black Leaf 40” cannot be purchased 
locally but, at my request, Messrs. E. O. Hall & Son have ordered 
a supply and within a few weeks it will be on sale in Honolulu. 
I have been surprised by the reports of serious damage done 
to cabbage, during the winter months, by the “cabbage worm” 
( Pontia rapae). On the mainland I have never experienced any 
difficulty to control this species by spraying with arsenicals. 
Spraying with Paris green was reported as ineffective by one 
local grower and to test the efficiency of this poison, when prop- 
erly applied, under local conditions, I sprayed a patch of cabbage 
which was infested by the larvae of this species and obtained 
absolutely successful results. The mixture used in this experi- 
ment was at the rate of two pounds of Paris green and eight 
pounds of whale-oil soap in 100 gallons of water. The applica- 
tion was made at 5 p. m. and at 10 a. m. the following day every 
“worm” on the sprayed plants was dead. Judging from the uni- 
formly successful results I have obtained, both locally and on the 
mainland, I am convinced that the failure reported by the local 
grower was due to the lack of a thorough application. 
When spraying for this “Worm” either arsenate of lead or 
Paris green may be used, but personally I prefer the latter be- 
cause of its quicker killing effects. Cabbage leaves are very 
smooth and it is necessary to add some sticky material to the mix- 
ture, otherwise the spray will collect in large drops and much of 
it will roll off of the plants. Whale-oil soap has proved very 
successful as a “sticker” and when it is added to the mixture an 
exceedingly light, even coat of the poison can be applied to the 
plants. Refuse molasses may be used in place of the soap, but the 
poison will then be much more readily washed from the plants by 
rains than if soap were used. The mixture should be applied to 
the plants from above and preferably from two sides, as a fine, 
forceful spray and an effort should be made to wet, as far as possi- 
ble, every portion of the foliage. Thorough work should be in- 
sisted upon and if spraying is commenced early in the season, 
before the “worms” have had an opportunity to multiply greatly 
and' do serious damage, there seems to be no reason why this 
pest cannot be as easily and as successfully controlled in these 
islands as it is on the mainland. 
During the latter part of the month, at the request and with 
the cooperation of Mr. F. G. Krauss, I commenced a series of 
experiments on Aphis maidis, a plant louse, which is seriously 
infesting an acre plot of broom corn grown on the U. S. Experi- 
ment .Station grounds. Owing to their low value it is not ordi- 
narily considered practicable to spray cereal crops for insect pests, 
but as broom corn promises to be, comparatively, a very valuable 
crop, it was thought desirable to undertake these experiments. 
