POTATO DISEASES IN HAWAII. 13 
Modification* of Bordeaux mUturc for the control of leaf -eating 
insects. — For controlling leaf-eating insects, such as the army worm 
or " poko," and as a possible aid in combating the tuber moth. Paris 
green may be used in Bordeaux at the rate of 1 pound to 50 gallons. 
Usually Bordeaux mixture contains a sufficient excess of lime to 
neutralize the Paris green and no burning of the foliage results. 
but if lime of doubtful quality is used in preparing the Bordeaux. 
an amount of lime equal in weight to the Paris green should be added 
to prevent burning. 
The usual method of destroying leaf-cutting insects (fig. 5. p. 31), 
however, is by adding arsenate of lead to Bordeaux mixture at the rate 
of about 3 pounds to 50 gallons. Whether this form of poisoning 
will prove more satisfactory for the leaf-eating cutworms or " pokos " 
than the locally commonly used flour-Paris-green-dust bait remains 
to be seen. For the tuber moth, arsenate of lead in Bordeaux will 
probably be of considerable benefit. 
Lime-sulphur spray or dry sulphur for the control of mites. — For 
the control of the potato mite (Pis. XII and XIII). which in dry 
and hot situations causes the death of young growth and premature 
development of the plant, a lime-sulphur spray made up as follows 
has been found effective : 
Sulphur pound 1 
Quicklime do 1 
Water to make gallons 20 
Boil the sulphur and quicklime in a gallon of water in a kettle 
or pan until they combine into a yellowish sirupy liquid, this usually 
requiring about three-quarters of an hour. Dilute to make 20 gal- 
lons of spray mixture. 
Dry surphur dusted upon the foliage with an insect-powder blower 
is likewise effective in the control of mites. 
Soil fungicides far Sclerotium wilt. — Ammoniacal copper carbon- 
ate solution and "eau celeste." which contain copper in soluble form. 
are recommended as soil fungicides in case of Sclerotium wilt 
(p. 26). The chemicals needed to make sufficient solution for 50 
gallons of copper carbonate fungicide are as follows : 
Copper carbonate ounces__ 5 
Ammonia < 2G° Baume) pints__ 3 
Water to make gallons— 50 
To a gallon of water in a wooden vessel add the ammonia and stir. 
Add the copper carbonate a little at a time, stirring constantly. Con- 
tinue to add the chemical until no more will dissolve. Allow any 
undissolved carbonate to settle to the bottom and draw off the clear 
blue supernatant liquid. This solution does not keep well for more 
