30 
BULLETIN 45, HAWAII EXPERIMENT STATION. 
cated by mining often visible just under the skin and by slight webbing near 
the eyes, they should be carefully sorted at once. Those infested should be 
either destroyed immediately by burning or fumigated if they are held for use 
as stock feed. Those still unimpaired should be fumigated as described below 
and placed out of reach of the moths and of further infestation. 
Fumigation : Place the tubers to be fumigated in a room that can be sealed. 
For every 1,000 cubic feet of space to be fumigated place from 1 to 2 pounds 
of carbon bisulphid in a shallow dish or pan and set it in the top of the room. 
The amount of the chemical varies with the tightness of the room. For small 
containers the following amounts are recommended : Ten-gallon " sake " barrel, 
one-tenth to one-fifth ounce ; 50-gallon wine barrel, one-half to 1 ounce. After the 
chemical is placed in the top of the room or container, seal up immediately and 
leave undisturbed for 24 hours. Remove and ventilate the material for a short 
time and place in moth-proof storage, if possible. If the potatoes are held in 
storage for any length of time they should be examined at frequent intervals for 
further infestation and treated again if necessary. Seed potatoes may be fumi- 
gated if the lot is suspected of containing worm-infested tubers. They must be 
fumigated before the sprouts are prominent, as otherwise the tubers will be 
killed. Carbon bisulphid is volatile and highly inflammable. Keep away from 
fire. The fumes are poisonous. Do not inhale. 
Spraying: The use of Paris green or other arsenicals in Bordeaux mixture 
(p. 10) when the latter is being regularly applied "will probably be of some 
benefit in combating the tuber moth. 
Cutworms, Army Worms or " Pokos," Snails, Etc. 
Of insects injurious to potatoes, the cutworms (fig. 5), especially 
the leaf -eating form locally known as " poko," rank next to the tuber 
Fig. 5. — Variegated cutworm (Peridroma margaritosa) : a, Moth ; h, normal form of 
caterpillar, side view ; c, same in curved position ; d, dark form, view of back ; e, 
greatly enlarged egg, seen from side; f, egg mass on twig. (From U. S. Dept. Agr., 
Farmers' Bui. 739.) 
