332 
entomological investigations along practically the same lines as 
indicated in my report for August. 
Fully two-thirds of the time I have spent in the field making 
experiments and observations and taking notes on the various 
insect pests of vegetable crops and ornamental plants. I have also 
devoted some of the time spent in the field to demonstration 
work and in this way have taught some of the growers the proper 
methods of preparing and applying insecticides. 
The time not spent in the field has been devoted to breeding 
insects, writing notes, letters, and the manuscript of reports and 
articles for publication. I have worked on an article concerning 
my experiments and observations on Macrosiphum sanborni, at 
odd moments, when more pressing work did not claim my atten- 
tion and now have the manuscript nearly completed. 
I have paid particular attention to making careful, accurate 
notes on my experiments and field and insectary observations. 
These notes, which accumulate rapidly, I have carefully written 
and filed and they form a permanent and valuable addition to the 
office records. 
The experiments on the melon fly (Daciis cuciirhifae) and the 
Japanese beetle (Adorctiis temiimaculatus) have been continued 
and some gratifying results obtained. Additional experiments 
have also been made on several species of plant lice, mealy bugs 
and on three cabbage and beet pests. 
The nicotine preparation known as ^‘Black Leaf 40” has con- 
tinued to give excellent results on plant lice and mealy bugs 
when used in combination with whale-oil soap and prooerly 
applied by spraying. After manv experiments, I have deter- 
mined the most satisfactory combination to be “Black Leaf 40” 
1 fitud ounces and whale-oil soap 4 ounces in 5 gallons of 
water. The soap aids the spray in adhering to the bodies of the 
insects and, judging from my experiments, soap or some other 
adherent is necessarv if good results are to be obtained. If this 
solution is thoroughlv applied to the infested plants as a fine, 
forceful spray it can be relied upon to kill every plant louse that 
is wet bv it. Many species of mealy bugs can also be readily 
killed m this manner, but such a species as Pscudococcns filamen- 
tosus, which is covered with a thick, cottony secretation, is more 
difficult to kill. 
One particularly g-ood feature of this solution is its almost 
immediate killing effect on insects spraved with it. I have 
obtained successful results from applications which were followed 
within a half hour b}^ heavv rains. An insecticide which will give 
good results under such circumstances is especially valuable in a 
climate such as we have in many parts of the Islands, where fre- 
quent rains would wash off the sprav and thus prevent satisfac- 
tory results if a more slowlv acting material were used. Another 
point in favor of this solution is that it is not injurious to any but 
