22 THE SUGAR-CANE INSECTS OF HAWAII. 
characteristic of all floral honeys. The larger amount of honey- 
dew is obtained from the insects on the young plant cane, 
for there the leafhoppers are more abundant. The amount of 
honeydew gathered depends on the maturity of the cane and the 
amount of rain which washes the secretion from the leaves. 
CONTROL OF THE LEAFHOPPER. 
Direct MEASURES. 
Insecticides —Those familiar with the culture of sugar cane will 
readily understand the difficulty of getting in and through the 
fields after the cane obtains any height. This difficulty renders the 
use of insecticides as a remedy unpractical. In Hawaii such a 
method becomes still more difficult because of the prevailing slope 
of the cane lands and the manner in which the fields in many dis- 
tricts are laid out for purposes of irrigation. The feeding habits 
of the leafhopper are such that a contact poison or irritant would be 
necessary for its destruction, and the activity of the leafhoppers— 
that is, the suddenness with which they disperse at the least dis- 
turbance—still further prevents the successful application of a con- 
tact insecticide. Then, too, the cane fields of Hawaii are subject 
to prevailing winds, which greatly interfere with the use of any 
substance in the form of a spray. In the face of the above difhi- 
culties the writer attempted the destruction of the leafhopper by 
direct measures and found that an application of kerosene emulsion 
applied in the shape of a finely divided stream with considerable 
force was capable of killing only a small percentage. A mixture of 
lime and caustic soda was also applied, with negative results. Lime, 
prepared by reducing fresh stone lime to a powder by the use of 
solutions of copper sulphate and caustic soda, was applied as a dust 
on cloudy days, or just after showers, and while in comparison to 
spraying a much larger area was covered, and the dust came in 
contact with a large percentage of the leafhoppers, no appreciable 
beneficial results were observed. 
Collection by nets—Ordinary sweeping nets supplied with short 
handles were placed in the hands of the laborers, and the leafhoppers 
were collected by having the laborers go in a body through adjoiming 
rows and sweep the nets over the cane leaves. The insects collected 
were dumped from the nets into buckets of water and kerosene at 
the ends of the rows. While immense numbers were captured in 
this way, the number collected and the area covered were so small 
in comparison to the abundance of the leafhoppers and to the extent 
of the infested area that this measure was also discarded. 
Cutting and burning in the infested centers—The direct measures 
of control advised by the writer were confined to the cutting down 
