﻿LIME-SULPHUR 
  A 
  STOMACH 
  POISON 
  FOR 
  INSECTS. 
  

  

  83 
  

  

  Arsenate 
  of 
  lead 
  at 
  strengths 
  varying 
  from 
  h-50 
  to 
  5-50 
  was 
  used 
  

   in 
  comparison 
  with 
  the 
  lime-sulphur 
  solution. 
  Arsenate 
  of 
  lead 
  and 
  

   lime-sulphur 
  were 
  also 
  used 
  together 
  at 
  various 
  strengths 
  (Tables 
  

   I 
  and 
  IV). 
  In 
  the 
  case 
  of 
  the 
  arsenate 
  of 
  lead 
  and 
  the 
  lime- 
  

   sulphur 
  most 
  of 
  the 
  feeding 
  was 
  done 
  during 
  the 
  first 
  three 
  or 
  four 
  

   days. 
  However, 
  in 
  no 
  instance 
  was 
  there 
  much 
  feeding 
  during 
  the 
  

   first 
  24 
  hours, 
  as 
  the 
  larvae 
  were 
  more 
  or 
  less 
  unsettled 
  until 
  they 
  

   found 
  a 
  suitable 
  place 
  for 
  their 
  web. 
  This 
  was 
  true 
  on 
  the 
  unsprayed 
  

   as 
  well 
  as 
  the 
  sprayed 
  leaves. 
  

  

  It 
  will 
  be 
  found 
  in 
  the 
  following 
  pages 
  that 
  the 
  rate 
  of 
  killing 
  is 
  

  

  fairly 
  uniform 
  in 
  all 
  experiments. 
  Since, 
  however, 
  the 
  tests 
  were 
  

  

  conducted 
  throughout 
  the 
  season 
  under 
  different 
  climatic 
  conditions, 
  

  

  slight 
  variations 
  exist, 
  

  

  RESULTS. 
  

  

  Experiment 
  I. 
  

  

  The 
  results 
  given 
  in 
  Table 
  I 
  are 
  taken 
  from 
  an 
  experiment 
  to 
  obtain 
  

   data 
  on 
  the 
  killing 
  effect 
  on 
  the 
  fall 
  webworm 
  of 
  various 
  chemicals 
  

   combined 
  with 
  lime-sulphur. 
  Lot 
  1 
  was 
  the 
  unsprayed 
  check; 
  lot 
  2 
  

   was 
  sprayed 
  with 
  lime-sulphur 
  alone 
  at 
  the 
  strength 
  of 
  H-50, 
  and 
  

   lot 
  3 
  with 
  lime-sulphur, 
  H-50, 
  in 
  combination 
  with 
  arsenate 
  of 
  lead, 
  

   2-50. 
  In 
  the 
  course 
  of 
  a 
  few 
  days 
  it 
  was 
  observed 
  that 
  several 
  larvae 
  

   on 
  the 
  lot 
  sprayed 
  with 
  lime-sulphur 
  were 
  dying. 
  The 
  20 
  larvae 
  of 
  this 
  

   lot 
  were 
  dead 
  at 
  the 
  end 
  of 
  13 
  days, 
  as 
  against 
  7 
  days 
  required 
  to 
  kill 
  

   all 
  the 
  larvae 
  with 
  the 
  combination 
  of 
  arsenate 
  of 
  lead 
  and 
  lime-sul- 
  

   phur. 
  On 
  the 
  unsprayed 
  lot, 
  at 
  the 
  end 
  of 
  72 
  days, 
  4 
  larvae 
  were 
  

   recorded 
  dead, 
  12 
  had 
  pupated, 
  and 
  4 
  were 
  missing. 
  

  

  Table 
  I. 
  — 
  Tests 
  of 
  the 
  killing 
  effect 
  on 
  the 
  fall 
  webworm 
  of 
  lime-sulphur 
  alone 
  and 
  com- 
  

   bined 
  with 
  arsenate 
  of 
  lead. 
  

  

  [Experiment 
  started 
  July 
  20 
  

  

  1912, 
  Benton 
  Harbor, 
  Mich., 
  20 
  larvae 
  in 
  each 
  lot.] 
  

  

  

  

  Larvae 
  dying 
  in 
  each 
  lot. 
  

  

  Date 
  of 
  examina- 
  

   tion. 
  

  

  Lar\;e 
  dying 
  in 
  each 
  lot. 
  

  

  Date 
  of 
  examina- 
  

   tion. 
  

  

  Lot 
  1— 
  

   Check 
  

  

  (un- 
  

   sprayed). 
  

  

  Lot 
  2— 
  

   Lime- 
  

   sulphur, 
  

  

  l 
  :-;>(>. 
  

  

  Lot 
  3— 
  

  

  Lime- 
  

   sulphur, 
  

   14-50, 
  

   and 
  

   arsenate 
  

   of 
  lead, 
  

   2-50. 
  

  

  Lot 
  1— 
  

   Check 
  

   (un- 
  

   sprayed). 
  

  

  Lot 
  2— 
  

   Lime- 
  

   sulphur, 
  

   l.J-50. 
  

  

  Lot 
  3— 
  

   Lime- 
  

   sulphur. 
  

   1J-50, 
  

   and 
  

   arsenate 
  

   of 
  lead. 
  

   2-50. 
  

  

  July 
  22 
  1 
  

  

  23 
  

  

  

  Aug. 
  12 
  

  

  

  

  

  

  

  14 
  

  

  

  

  

  21 
  

  

  

  

  1 
  

   7 
  

   10 
  

   2 
  

  

  16 
  

  

  

  

  

  2G 
  

  

  

  

  IS 
  

  

  

  

  

  

  

  4 
  

   3 
  

   3 
  

  

  4 
  

  

  21 
  

  

  

  

  

  

  

  27 
  

  

  

  23 
  

  

  

  

  

  28 
  

  

  

  Sept. 
  2 
  

  

  2 
  

  

  

  

  29... 
  

  

  

  

  ' 
  LQ 
  

  

  

  

  80 
  

  

  

  

  so 
  

  

  

  

  31 
  

  

  

  4 
  

  

  

  Total 
  number 
  

  

  dead 
  

  

  Number 
  of 
  da 
  V8 
  re- 
  

   quired 
  to 
  kill... 
  

  

  

  

  

  Aur. 
  1 
  

  

  

  

  1 
  

  

  20 
  

   13 
  

  

  

  2 
  

  

  

  

  

  

  

  

  

  4 
  

  

  

  

  7 
  

  

  6 
  

  

  

  

  square 
  inches 
  of 
  

   foliage 
  consumed. 
  

  

  

  

  

  

  

  

  

  

  

  

  