METHODS OF CONTROL. 11 



Poisoned hcdt. — This same orower employed a bait of poisoned 

 bran and molasses, about as advised for cutworms, but without ma- 

 terial eifect, the caterpillars preferrinf? the ferns. 



Carbon hisulphid. — Fumigation \\'\i\\ 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 w^as 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. 



Band 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 gi'ower would 

 obtain the best success by hand methods, one of the best methods 

 consisting in shaking each individual plant over the gi'ound 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 2^ pounds to 50 gallons of water, applied 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, avouIcI 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 Q^g;, or undergoing their molts, it 

 should assist very materially in reducing tlie numbers of the pest. 



