SOLUBLE POISONS IN THE POISONED BAIT SPRAY. 151 



flies were collected in jelly-glasses, where they became para- 

 lyzed in about fifteen minutes and in half an hour they were 

 dead. 



An application of the bait containing the soluble poison was 

 made on July 22 and 26, a pint being sprayed upon the lower 

 branches of a 20-years-old Maiden Blush tree. In a table the 

 author gives a daily record of the drops from this treated tree 

 and the number of larvae which bored out of the fallen fruit. 

 All the windfalls picked up under the baited tree after August 

 15, were absolutely free from larvae. From an untreated tree 

 of the same variety in another field, 180 drops were gathered 

 on August 23, and from these, larvae emerged during Septem- 

 ber. On the other hand, 115 drops collected on the same date 

 from the treated tree failed to show a trace of a single maggot. 

 "Hence it is quite evident that the flies deposited no eggs in the 

 fruit of the sprayed tree after the application of July 26." 



In the season of 1912, Illingworth used arsenate of lead and 

 molasses diluted with water. On July 3, Red Astrachan trees 

 received the first treatment. Five applications of the spray 

 were made during the season. "On August 5, the Red Astra- 

 chan apples were ripening and showed no trace of the maggots."' 



"Slight difficulty was experienced in controlling the flies on a 

 seedling variety of sweet apples," due to showers which came 

 up nearly every afternoon during the period that the fruit fly 

 remedy was being applied to the tree. "Even in this case, how- 

 ever, the fruit was vastly improved over former years." No 

 mention is made of the number of trees treated and no check 

 or control trees were used in 1912. 



Ross* "tested two spray mixtures, one composed of arsenate 

 of lead, glycerine and molasses and the other of Paris green, 

 glycerine and molasses, but neither yielded satisfactory re- 

 sults," in the control of the apple fruit fly in Ontario. 



For a period of three years, O'Kanef tested the poisoned bait 

 to control the apple trypetid in New Hampshire. His records 

 are taken for the most part from typical lots of sprayed trees, 

 of which surrounding conditions were accurately known. Such 

 field tests as are recorded consisted of two trees treate 1 witn 

 the poisoned sweet in the season, of 1910, three trees in 1911 



*Ent. Soc. of Ontario. Report 1912, pp. 67-72. 

 tNew Hampshire Station Bui. 171, pp. 1-120. 



