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  larvae 
  of 
  the 
  tobacco 
  Crambus 
  have 
  been 
  found 
  feeding 
  are 
  : 
  wild 
  

   aster 
  or 
  " 
  stickweed 
  " 
  {Aster 
  ericoides 
  and 
  other 
  species), 
  wild 
  carrot 
  

   (Daucus 
  car 
  Ota), 
  sheep 
  sorrel 
  (Rumex 
  acetosella), 
  Senecio 
  jacobaea, 
  

   and 
  white-top 
  (flea-bane) 
  (Erigeron 
  annuus) 
  and 
  other 
  species. 
  

   It 
  is 
  probable 
  that 
  severe 
  injury 
  to 
  cultivated 
  crops 
  only 
  occurs 
  in 
  

   localities 
  where 
  natural 
  food-plants 
  are 
  exceedingly 
  abundant, 
  and 
  

   where 
  crops 
  are 
  planted 
  at 
  the 
  time 
  the 
  larvae 
  are 
  completing 
  their 
  

   growth. 
  The 
  eradication 
  or 
  control 
  of 
  the 
  two 
  chief 
  food-plants, 
  

   therefore, 
  will 
  result 
  in 
  comparative 
  immunity 
  from 
  loss 
  due 
  to 
  this 
  

   insect. 
  

  

  The 
  greatest 
  emergence 
  of 
  the 
  moths 
  takes 
  place 
  during 
  the 
  first 
  and 
  

   second 
  weeks 
  of 
  August, 
  although 
  individuals 
  occur 
  from 
  the 
  end 
  of 
  

   June 
  to 
  the 
  beginning 
  of 
  September. 
  The 
  females 
  die 
  soon 
  after 
  

   egg-laying, 
  the 
  average 
  number 
  of 
  eggs 
  being 
  177, 
  and 
  there 
  is 
  

   apparently 
  only 
  one 
  generation 
  a 
  year, 
  the 
  eggs 
  hatching 
  in 
  summer 
  

   and 
  the 
  larvae 
  completing 
  their 
  growth 
  during 
  the 
  following 
  year. 
  

   Most 
  of 
  the 
  larvae 
  are 
  in 
  the 
  pupal 
  stage 
  during 
  the 
  first 
  half 
  of 
  July. 
  

   Larvae 
  collected 
  from 
  maize 
  are 
  considerably 
  hghter 
  in 
  colour 
  than 
  

   those 
  from 
  tobacco. 
  The 
  moths 
  fly 
  during 
  late 
  afternoon, 
  on 
  dark 
  

   days, 
  and 
  during 
  the 
  early 
  part 
  of 
  the 
  night, 
  and 
  are 
  attracted 
  to 
  

   light 
  in 
  comparatively 
  small 
  numbers. 
  

  

  When 
  meadows 
  are 
  ploughed 
  up 
  and 
  planted 
  with 
  tobacco, 
  serious 
  

   injury 
  frequently 
  occurs, 
  but 
  this 
  is 
  invariably 
  due 
  to 
  the 
  presence 
  of 
  

   the 
  weeds 
  mentioned 
  above, 
  and 
  does 
  not 
  occur 
  where 
  there 
  had 
  

   previously 
  been 
  a 
  clean 
  growth 
  of 
  grass 
  or 
  clover. 
  The 
  larvae, 
  which 
  

   feed 
  chiefly 
  at 
  night, 
  attack 
  tobacco 
  soon 
  after 
  planting, 
  usually 
  

   just 
  below 
  the 
  surface 
  of 
  the 
  ground, 
  but 
  the 
  whorls 
  of 
  terminal 
  

   leaves 
  of 
  newly 
  set 
  plants 
  are 
  also 
  damaged. 
  The 
  smaller 
  individuals 
  

   often 
  enter 
  the 
  stalk 
  and 
  tunnel 
  upward, 
  and 
  when 
  not 
  feeding 
  may 
  

   be 
  found 
  in 
  cyhndrical, 
  web-hned 
  galleries 
  extending 
  from 
  the 
  plant, 
  

   several 
  inches 
  below 
  the 
  surface 
  of 
  the 
  soil. 
  Injured 
  plants 
  may 
  

   usually 
  be 
  detected 
  by 
  their 
  stunted 
  or 
  wilted 
  appearance, 
  which 
  is 
  

   especially 
  noticeable 
  in 
  dry 
  weather. 
  

  

  In 
  the 
  case 
  of 
  maize, 
  the 
  larvae 
  attack 
  the 
  young 
  plants 
  near 
  the 
  

   ground, 
  but 
  when 
  the 
  stalks 
  reach 
  a 
  height 
  of 
  a 
  foot 
  or 
  more 
  compara- 
  

   tively 
  little 
  damage 
  is 
  done. 
  Injury 
  is 
  less 
  severe 
  in 
  wet 
  weather, 
  

   as 
  the 
  plants 
  are 
  more 
  vigorous 
  and 
  the 
  weeds 
  more 
  plentiful. 
  

  

  Before 
  pupating, 
  the 
  larvae 
  seem 
  to 
  pass 
  a 
  rather 
  long 
  inactive 
  period 
  

   in 
  their 
  cells. 
  Pupation 
  takes 
  place 
  at 
  a 
  distance 
  of 
  from 
  1 
  to 
  6 
  inches 
  

   from 
  the 
  food-plant 
  and 
  at 
  a 
  depth 
  varying 
  from 
  one-half 
  to 
  4 
  inches 
  ; 
  

   the 
  average 
  duration 
  of 
  the 
  pupal 
  stage 
  is 
  from 
  10 
  to 
  15 
  days. 
  

  

  Besides 
  spiders 
  of 
  several 
  species, 
  various 
  Carabid 
  beetles 
  feed 
  on 
  

   the 
  larvae 
  of 
  C. 
  caliginosellus, 
  including 
  Calosoma 
  calidum, 
  F., 
  and 
  

   Chlaenius 
  tomentosus, 
  Say. 
  Adults 
  and 
  larvae 
  of 
  Harpalus 
  pennsyl- 
  

   vanicitSy 
  De 
  G., 
  and 
  H. 
  faunus, 
  Say, 
  may 
  also 
  attack 
  them. 
  Ants 
  

   occasionally 
  attack 
  the 
  larvae 
  and 
  among 
  the 
  bird 
  enemies 
  are 
  : 
  quails 
  

   (Colinus 
  virginianus), 
  kingbirds 
  (Tyrannus 
  tyrannus), 
  the 
  wood 
  

   pewee 
  (Myiochares 
  virens), 
  and 
  it 
  is 
  thought 
  that 
  barn-swallows 
  and 
  

   meadow-larks 
  are 
  also 
  beneficial. 
  

  

  As 
  tests 
  with 
  various 
  insecticides 
  and 
  repellants, 
  including 
  arsenate 
  

   of 
  lead, 
  Paris 
  green, 
  tobacco 
  extract, 
  nicotin 
  sulphate, 
  tobacco-dust, 
  

   kerosene, 
  kainit, 
  and 
  calcium 
  cyanamide, 
  gave 
  no 
  results 
  which 
  would 
  

   indicate 
  any 
  practical 
  value, 
  the 
  author 
  recommends 
  cultural 
  methods 
  

  

  