﻿265 
  

  

  The 
  report 
  further 
  refers 
  to 
  the 
  spraying 
  of 
  the 
  trees 
  with 
  sulphate 
  

   of 
  iron, 
  which 
  had 
  for 
  its 
  object 
  the 
  removal 
  of 
  the 
  moss, 
  lichen, 
  etc., 
  

   and 
  gives 
  a 
  general 
  review 
  of 
  the 
  results 
  of 
  the 
  campaign. 
  The 
  pests 
  

   mentioned 
  above 
  were 
  found 
  also 
  in 
  other 
  parts 
  of 
  the 
  government 
  

   outside 
  the 
  two 
  districts 
  specially 
  dealt 
  Avith. 
  From 
  the 
  town 
  of 
  

   Kaluga 
  Byturus 
  tomentosus, 
  F., 
  and 
  Cossus 
  cossns, 
  L., 
  were 
  reported. 
  

   The 
  caterpillars 
  of 
  the 
  latter 
  were 
  found 
  in 
  poplar 
  trees 
  between 
  the 
  

   14th 
  August 
  and 
  the 
  19th 
  September 
  ; 
  the 
  first 
  pupation 
  took 
  place 
  on 
  

   the 
  23rd 
  August. 
  

  

  As 
  to 
  the 
  pests 
  of 
  field 
  crops, 
  chief 
  amongst 
  them 
  were 
  Agriotes 
  

   lineatus, 
  L., 
  and 
  Euxoa 
  segefum, 
  Schiff. 
  The 
  larvae 
  of 
  A. 
  lineatus 
  

   caused 
  great 
  injury 
  to 
  some 
  fields 
  in 
  the 
  district 
  of 
  Kozelsk, 
  during 
  

   the 
  autumn 
  of 
  1912. 
  Investigation 
  conducted 
  on 
  the 
  same 
  fields 
  in 
  

   April 
  1913 
  again 
  showed 
  their 
  presence. 
  In 
  order 
  to 
  ascertain 
  the 
  

   degree 
  of 
  the 
  infestation 
  samples 
  of 
  the 
  soil 
  were 
  taken 
  out 
  and 
  care- 
  

   fully 
  examined 
  by 
  screening, 
  the 
  soil 
  having 
  previously 
  being 
  made 
  

   friable 
  ; 
  for 
  each 
  sample 
  a 
  clod 
  of 
  earth 
  about 
  1 
  J 
  feet 
  square 
  and 
  about 
  

   lOJ 
  inches 
  thick 
  was 
  dug 
  out 
  from 
  each 
  dessiatine 
  (2'7 
  acres) 
  ; 
  these 
  

   samples 
  showed 
  an 
  average 
  presence 
  of 
  20,000 
  larvae 
  per 
  acre. 
  Two 
  

   kinds 
  of 
  remedies 
  were 
  tried 
  ; 
  potato 
  baits 
  poisoned 
  with 
  Schweinfurt 
  

   green, 
  and 
  suffocating 
  with 
  carbon 
  bisulphide 
  (CSg). 
  The 
  first 
  

   experiment 
  was 
  conducted 
  in 
  the 
  following 
  way 
  : 
  slices 
  of 
  potatoes 
  

   were 
  put 
  into 
  a 
  solution 
  of 
  1 
  per 
  cent. 
  Schweinfurt 
  green 
  in 
  sal 
  ammoniac 
  

   and 
  left 
  there 
  for 
  about 
  24 
  hours 
  ; 
  the 
  potatoes 
  were 
  then 
  left 
  in 
  the 
  

   open 
  air 
  till 
  the 
  smell 
  of 
  ammonia 
  was 
  lost, 
  after 
  which 
  they 
  were 
  set 
  

   in 
  trap 
  holes 
  of 
  about 
  8 
  inches 
  square 
  and 
  9 
  inches 
  deep, 
  which 
  were 
  

   covered 
  with 
  boards. 
  Such 
  holes 
  were 
  dug 
  at 
  a 
  distance 
  of 
  20 
  paces 
  

   one 
  from 
  another 
  round 
  the 
  attacked 
  spots. 
  Only 
  a 
  few 
  specimens 
  

   of 
  dead 
  larvae 
  were 
  discovered 
  later 
  in 
  these 
  traps, 
  but 
  in 
  the 
  soil 
  

   round 
  them 
  more 
  larvae, 
  motionless, 
  and 
  of 
  a 
  peculiar 
  blueish 
  brown 
  

   colour 
  were 
  found 
  ; 
  of 
  48 
  such 
  larvae 
  which 
  were 
  put 
  into 
  a 
  glass 
  with 
  

   earth 
  and 
  food, 
  32 
  perished 
  in 
  about 
  10 
  days, 
  i.e. 
  66J 
  per 
  cent. 
  Evi- 
  

   dently 
  the 
  larvae 
  had 
  left 
  the 
  holes 
  after 
  having 
  eaten 
  the 
  poisoned 
  

   baits. 
  Details 
  are 
  given 
  of 
  an 
  experiment 
  with 
  carbon 
  bisulphide 
  ; 
  

   but 
  the 
  percentage 
  of 
  larvae 
  killed 
  was 
  only 
  32*1 
  per 
  cent, 
  and 
  38 
  '3 
  per 
  

   cent. 
  Owing 
  to 
  the 
  cost 
  of 
  this 
  remedy 
  it 
  is 
  not 
  considered 
  possible 
  

   to 
  increase 
  the 
  amount 
  of 
  CS.2, 
  but 
  evidently 
  the 
  time 
  during 
  which 
  

   it 
  remained 
  in 
  the 
  earth 
  was 
  not 
  sufficient 
  to 
  permit 
  of 
  complete 
  

   diffusion 
  in 
  that 
  particular 
  soil. 
  

  

  Agriotes 
  larvae 
  also 
  injured 
  various 
  wdnter-sown 
  fields 
  in 
  September. 
  

   A 
  part 
  of 
  one 
  field 
  manured 
  with 
  superphosphate 
  was 
  injured, 
  while 
  a 
  

   neighbouring 
  part 
  manured 
  with 
  basic 
  slag 
  was 
  not 
  attacked 
  by 
  the 
  

   pests. 
  According 
  to 
  the 
  proprietor 
  of 
  the 
  field, 
  the 
  larvae 
  last 
  year 
  

   also 
  attacked 
  a 
  part 
  manured 
  with 
  basic 
  slag, 
  when 
  the 
  latter 
  was 
  

   scattered 
  about 
  the 
  field 
  ; 
  while 
  this 
  year 
  the 
  method 
  of 
  manuring 
  

   was 
  to 
  lay 
  the 
  slag 
  in 
  regular 
  fines. 
  As 
  a 
  rule, 
  crops 
  manured 
  during 
  

   the 
  summer 
  with 
  dung 
  were 
  able 
  to 
  withstand 
  the 
  attacks 
  of 
  the 
  

   wireworms, 
  although 
  there 
  were 
  large 
  larvae 
  in 
  the 
  earth 
  of 
  such 
  fields 
  ; 
  

   evidently 
  the 
  dung 
  caused 
  a 
  strong 
  and 
  rapid 
  growth 
  of 
  the 
  plants 
  

   It 
  is 
  also 
  reported 
  that 
  on 
  one 
  field, 
  part 
  of 
  which 
  was 
  sown 
  with 
  grain 
  

   (rye) 
  disinfected 
  with 
  formafin, 
  owing 
  to 
  its 
  suffering 
  from 
  a 
  fungus 
  

   disease 
  (Tilletia 
  secalis, 
  Kuhn), 
  the 
  crop 
  was 
  very 
  heavy 
  ; 
  while 
  on 
  

   the 
  other 
  part, 
  where 
  no 
  such 
  process 
  was 
  applied 
  to 
  the 
  sowij 
  grain 
  

  

  (C26) 
  E 
  

  

  