SOLUBLE POISONS IN THE POISONED BAIT SPRAY. I07 



the use of a soluble poison can not be advocated. In orchards 

 where tent-caterpillars are controlled, defoliation caused by 

 spray injury is far less than the damage caused by these pests 

 in neglected orchards. Our experience shows that after fruit 

 growers have been convinced of the results obtained by the use 

 of the poisoned bait spray, many prefer sound fruit even if 

 burned foliage is the necessary price. 



The fruit fly remedy has been a complete failure in the con- 

 trol of the pest under town conditions. With four applications 

 of the spray the infestation varied from 4 to 98 per cent. 



Explanation oe Map. 



Map showing the location of the experimental area in which 

 an attempt was made to control the adult of the apple maggot 

 by means of the poisoned bait spray under orchard and town 

 conditions. The apple trees indicated by dots on the map were 

 isolated on one side by the Penobscot river and a bay of this 

 river. The location of six orchards are shown by the following 

 figures which represent the number of trees in each: 84, 31, 

 40, 57, 47 and 38. The principal part of each orchard is sit- 

 uated above the figures. A series of dashes represents the 

 boundary between two orchards or separates an orchard from 

 trees present in adjacent dooryards. The residential district 

 contained 274 apple trees scattered in the different yards. The 

 entire area covered about one square mile and contained a 

 total of 571 apple trees. 



A circle surrounding a dot shows the location of a sprayed 

 tree which was checked up with an untreated or control tree 

 situated on the outside of the experimental area. The follow- 

 ing is a list of varieties of apples that were used in checking up 

 the results : 



A — Alexander. M1-M2 = Milden. 



B = Bells Early. P = Pyrus prunifolia (Hybrid Crab) . 



C = Coles Quince. R = Rolfe. 



Di-D4 = Mcintosh Red. S = Large Red Siberian Crab. 



F1-F2 = Fameuse. T1-T9 = Tolman Sweet. 



H = Hyslop Crab. Ui-U2 = Munson Sweet. 



K1-K2 = Transcendent Crab. W = Wealthy. 



L = Benoni. X = Bellflower. 



