and 
\ 
METHODS OF CONTROL. ct 
Poisoned bait—This same grower employed a bait of poisoned 
bran and molasses, about as advised for cutworms, but without ma- 
terial effect, the caterpillars preferring the ferns. 
Carbon bisulphid—F umigation with carbon bisulphid was tried 
by Mr. Watson in June, 1908, but he stated that it had been of no 
avail in the destruction of this pest. In the same greenhouse, in 
charge of Mr. Watson, strips of cloth were saturated with carbon 
bisulphid and placed on the ground about the plants, but although 
this remedy was sometimes successful it was not entirely reliable 
since the caterpillars had necessarily to be where they would receive 
the fumes if they were to succumb. 
Hand picking.—The time-worn, laborious, but, if properly pursued, 
effective remedy of combating the insect by hand measures was em- 
_. ployed by numerous growers. One of these reported that the num- 
bers of the caterpillar had been materially reduced by hand picking 
and poisoning. Another grower made a practice of going over the 
ferns every day and picking off all the caterpillars that could be 
seen, thus reducing the numbers of the pest in his greenhouse. It 
seemed to be the consensus of opinion that the average grower would 
obtain the best success by hand methods, one of the best methods 
consisting in shaking each individual plant over the ground and 
trampling upon the caterpillars as they fall. 
Arsenate of lead—Arsenate of lead was advised, and an assistant 
was detailed to an infested greenhouse where this remedy was em- 
ployed, to determine the extent of injury and to advise measures for 
the possible extermination of the cutworms. On his arrival he was 
informed that several thousand had been hand picked from the ferns 
a day or two before and that over 200 had been picked from a space 
only 5 feet square. The plants had also been sprayed with arsenate 
of lead at the rate of 24 pounds to 50 gallons of water, apphed twice, 
but the final result was not reported. Some of the growers com- 
plained that lead arsenate, when used in a solution strong enough to 
kill the caterpillars, would at the same time leave a white deposit on 
the plants which destroyed their commercial value. Owing to the 
delicacy of ferns a spray of Paris green strong enough to kill the 
caterpillars would also burn the foliage. Paris green, properly com- 
bined with Bordeaux mixture, should not produce this effect. 
Hydrocyanic-acid gas fumigation.—Some of the local growers were 
advised by the writer to fumigate with hydrocyanic-acid gas, but 
it was not tried, so far as can be learned. If fumigation by this 
method were employed several times at about the time when the 
insects are hatching from the egg, or undergoing their molts, it 
should assist very materially in reducing the numbers of the pest. 
