﻿106 
  

  

  DECIDUOUS 
  FRUIT 
  INSECTS 
  AND 
  INSECTICIDES. 
  

  

  SPRAYING 
  EXPERIMENTS 
  AGAINST 
  THE 
  LARV^S. 
  

  

  The 
  experiments 
  against 
  the 
  larvae 
  were 
  conducted 
  in 
  the 
  Davis 
  

   orchard 
  at 
  Canon 
  City, 
  Colo. 
  This 
  orchard 
  consisted 
  of 
  many 
  varie- 
  

   ties, 
  namely, 
  Ben 
  Davis, 
  Missouri 
  Pippin, 
  Winesap, 
  Paragon, 
  Jeniton, 
  

   Rome 
  Beauty, 
  Jonathan, 
  Maiden 
  Blush, 
  Yellow 
  Transparent, 
  and 
  

   Red 
  Astrakhan. 
  There 
  were 
  also 
  a 
  few 
  trees 
  of 
  other 
  varieties. 
  

   The 
  orchard 
  as 
  a 
  whole 
  had 
  no 
  more 
  than 
  a 
  good 
  one-fifth 
  crop. 
  

   On 
  account 
  of 
  the 
  light 
  crop 
  it 
  was 
  difficult 
  to 
  determine 
  fairly 
  the 
  

   results 
  of 
  the 
  spraying 
  on 
  some 
  plats. 
  In 
  all 
  cases 
  the 
  material 
  was 
  

   applied 
  with 
  a 
  good 
  gasoline-power 
  outfit 
  and 
  a 
  pressure 
  ranging 
  

   from 
  150 
  to 
  200 
  pounds 
  was 
  maintained. 
  The 
  plats 
  contained 
  trees 
  

   as 
  follows: 
  I, 
  155; 
  II, 
  72; 
  III, 
  31; 
  IV, 
  63; 
  V, 
  46; 
  VI, 
  38; 
  VII, 
  26; 
  

   VIII, 
  30; 
  IX, 
  41; 
  X, 
  6. 
  

  

  The 
  results 
  are 
  shown 
  in 
  Table 
  VI. 
  

  

  Table 
  VI. 
  — 
  Spraying 
  experiments 
  against 
  the 
  larvx 
  of 
  the 
  fruit-tree 
  leaf 
  -roller, 
  Canon 
  

  

  City, 
  Colo., 
  1912. 
  

  

  Plat 
  

   No. 
  

  

  Treatment. 
  

  

  Percent- 
  

   age 
  of 
  

   injured 
  

   apples. 
  

  

  Percent- 
  

   age 
  of 
  

   sound 
  

  

  apples. 
  

  

  20.00 
  

  

  80.00 
  

  

  20.00 
  

  

  80. 
  00. 
  

  

  15.00 
  

  

  85.00 
  

  

  15.00 
  

  

  85.00 
  

  

  25.00 
  

  

  75.00 
  

  

  18.00 
  

  

  82.00 
  

  

  No 
  crop. 
  

  

  No 
  crop. 
  

  

  35.00 
  

  

  65.00 
  

  

  40.00 
  

  

  60.00 
  

  

  98.00 
  

  

  2.00 
  

  

  Condition 
  of 
  foliage. 
  

  

  I 
  

  

  II 
  

  

  III 
  

  

  IV 
  

  

  V 
  

   VI 
  

  

  VII 
  

  

  VIII 
  

  

  IX 
  

  

  X 
  

  

  Two 
  applications 
  of 
  arsenate 
  of 
  lead, 
  3 
  pounds 
  

   to 
  50 
  gallons 
  of 
  water, 
  May 
  2 
  and 
  May 
  17 
  and 
  

   18. 
  

  

  Two 
  applications 
  of 
  arsenate 
  of 
  lead, 
  3 
  pounds 
  

   to 
  50 
  gallons 
  of 
  water, 
  plus 
  4 
  ounces 
  Paris 
  

   green. 
  

  

  Two 
  applications 
  of 
  arsenate 
  of 
  lead, 
  3 
  pounds 
  

   to 
  50 
  gallons 
  water, 
  plus 
  40 
  per 
  cent 
  nicotine 
  

   solution 
  (1:1,000), 
  May 
  3 
  and 
  25. 
  

  

  One 
  application 
  of 
  arsenate 
  of 
  lead, 
  3 
  pounds 
  

   to 
  50 
  gallons 
  water, 
  plus 
  40 
  per 
  cent 
  nicotine 
  

   solution 
  (1:1,000), 
  May 
  3. 
  

  

  Two 
  applications 
  of 
  arsenate 
  of 
  zinc, 
  1 
  pound 
  

   to 
  50 
  gallons 
  water, 
  May 
  11 
  and 
  25. 
  

  

  One 
  application 
  of 
  Paris 
  green, 
  8 
  ounces 
  to 
  50 
  

   gallons 
  water, 
  plus 
  2 
  pounds 
  lime, 
  May 
  4; 
  

   one 
  application 
  of 
  Paris 
  green, 
  1 
  pound 
  to 
  

   50 
  gallons 
  water, 
  plus 
  2 
  pounds 
  lime, 
  May 
  18. 
  

  

  One 
  application 
  of 
  40 
  per 
  cent 
  nicotine 
  solu- 
  

   tion 
  at 
  1:800, 
  plus 
  2 
  pounds 
  of 
  soap, 
  May 
  11. 
  

  

  One 
  application 
  of 
  40 
  per 
  cent 
  nicotine 
  solu- 
  

   tion 
  at 
  1:800, 
  plus 
  2 
  pounds 
  of 
  soap, 
  May 
  18. 
  

  

  One 
  application 
  of 
  40 
  per 
  cent 
  nicotine 
  solu- 
  

   tion 
  at 
  1:1,000, 
  plus 
  2 
  pounds 
  of 
  soap, 
  May 
  18. 
  

  

  Check; 
  unsprayed 
  

  

  Good; 
  no 
  arsenical 
  injury. 
  

   Do. 
  

  

  Very 
  good; 
  no 
  arsenical 
  in- 
  

   jury. 
  

  

  Do. 
  

  

  Fair; 
  serious 
  arsenical 
  in- 
  

   jury. 
  

  

  Good; 
  slightly 
  burned 
  by 
  

   arsenical. 
  

  

  Fairly 
  good. 
  

   Fair. 
  

  

  Do. 
  

   Trees 
  nearly 
  defoliated. 
  

  

  Note.— 
  Plats 
  I, 
  IV, 
  VII, 
  VIII, 
  and 
  IX 
  were 
  sprayed 
  with 
  arsenate 
  of 
  lead 
  at 
  the 
  rate 
  of 
  3 
  pounds 
  to 
  50 
  

   gallons 
  of 
  water 
  for 
  the 
  codling 
  moth 
  when 
  the 
  petals 
  had 
  dropped. 
  Plats 
  II 
  and 
  VI 
  received 
  the 
  same 
  

   treatment 
  for 
  the 
  leaf-roller 
  as 
  for 
  the 
  first 
  codling-moth 
  application. 
  

  

  The 
  damage 
  to 
  fruit 
  was 
  determined 
  by 
  making 
  careful 
  counts 
  of 
  

   fruits 
  'from 
  various 
  trees 
  in 
  the 
  different 
  plats. 
  The 
  total 
  number 
  of 
  

   fruits 
  was 
  not 
  counted 
  in 
  any 
  case, 
  so 
  the 
  percentages 
  given 
  are 
  only 
  

   approximate. 
  On 
  Plat 
  VII 
  there 
  was 
  a 
  total 
  crop 
  failure. 
  

  

  As 
  will 
  be 
  noted, 
  the 
  best 
  results 
  were 
  obtained 
  on 
  Plats 
  III 
  and 
  

   IV, 
  where 
  a 
  combination 
  of 
  arsenate 
  of 
  lead 
  (3:50) 
  and 
  40 
  per 
  cent 
  

   nicotine 
  solution 
  was 
  used. 
  The 
  40 
  per 
  cent 
  nicotine 
  solution 
  was 
  

   found 
  to 
  be 
  effective 
  only 
  when 
  the 
  larvae 
  were 
  quite 
  small. 
  It 
  was 
  

  

  