8 INSECTS AFFECTING VEGETABLES. 



live larvae were counted on the underside of one leaf. These beds 

 were examined daily, and on September 7 it was concluded that the 

 experiment was a failure, as the larva?, except on the leaves which had 

 been thoroughly -prayed on the underside, were unharmed. It was 

 noted that on leaves which had been but partially sprayed on the 

 underside the larvae avoided the poisoned portion but continued to 

 feed on the part which had been missed by the .-pray. The failure of 

 this experiment was due to the habit the larvae have of feeding on the 

 underside of the leaves, without eating through the upper epi- 

 dermis. The mixture used in this experiment burned the partly con- 

 sumed leaves slightly but caused no extensive injury. 



Experiment No. 2. — Paris green. 2 pounds, and whale-oil soap. 8 

 pounds, in 100 gallons of water. September 7. three bed- of table 

 beets, each 10 yards in length and 1 yard wide, were sprayed with 

 about 3 gallons of thi> mixture. The same apparatus was used as in 

 experiment Xo. 1. A particular effort was made to wet the under sur- 

 face of the leaves thoroughly. The mixture adhered perfectly and an 

 extremely even distribution of the poison was obtained. The weather 

 was hot and clear. 



The following day nearly all the larva? were dead and the few 

 individual- which remained alive appeared very sick. September 10, 

 the beets were free of larvae and the foliage showed no burning by 

 the .-pray mixture. Two weeks later the sprayed plants were -till 

 free of larva', while beets in adjoining (check) beds were badly in- 

 fe.-ted. This experiment plainly demonstrates that if the spray is 

 applied properly, i. e., to the underside of the leaves, it can be de- 

 pended on to control thi> pest. 



In addition to the experiments with Paris green, a few preliminary 

 and somewhat inconclusive tests were made with arsenate of lead, 

 lead chromate. and lime-sulphur solution. For the sake of con- 

 venience these will be classed as experiments. 



Experiment Xo. J. — Arsenate of lead. H ounces, and molasses, 

 1 quart, in \\ gallons of water. This mixture was experimented 

 with as a poisoned bait for the melon fly (Dacus cucurbita Coq.), 

 and was not originally intended for use against the Hawaiian beet 

 webworm. September 7. a patch of Amaranthus. badly infested by 

 larva' varying in size from those recently hatched to others nearly 

 mature, was sprayed with some of this mixture. The spray Avas 

 applied Aery thoroughly to the upper 'and lower surfaces of the 

 leaves with the same apparatus as used in experiment Xo. 1. The 

 following day the larva 1 were unharmed. The leaves showed a good 

 even coat of the arsenate. The -prayed plants were kept under daily 

 observation until September 13, at which date they were destroyed. 

 On the !>th and 10th of September it was noted that the larvae were 

 growing nicely and appeared to relish the poison-coated leaves. 



