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  Oraf 
  (J. 
  E.). 
  A 
  Preliminary 
  Report 
  on 
  the 
  Sugar-Beet 
  Wireworm, 
  

   Bur. 
  Entom. 
  U.S. 
  Dept. 
  Agric, 
  Washington, 
  D.C., 
  Bull., 
  no. 
  123, 
  

   28tli 
  Feb. 
  1914, 
  68 
  pp., 
  23 
  pis., 
  9 
  figs. 
  

  

  The 
  sugar-beet 
  wireworm, 
  (Limonius 
  calif 
  ornicus, 
  Mannh.), 
  has 
  been 
  a 
  

   more 
  or 
  less 
  destructive 
  pest 
  on 
  sugar-beets 
  since 
  they 
  were 
  first 
  grown 
  

   in 
  California, 
  and 
  prior 
  to 
  that 
  time 
  was 
  known 
  as 
  an 
  alfalfa 
  and 
  maize 
  

   pest. 
  It 
  may 
  be 
  considered 
  the 
  worst 
  insect 
  enemy 
  of 
  the 
  sugar-beet, 
  

   because 
  it 
  is 
  constant, 
  appearing 
  every 
  year 
  to 
  a 
  greater 
  or 
  less 
  extent, 
  

   and 
  its 
  injury 
  occurs 
  in 
  such 
  a 
  manner 
  that 
  replanting 
  is 
  generally 
  

   impractiable. 
  The 
  beet 
  is 
  killed, 
  since 
  the 
  wireworm 
  cuts 
  into 
  and 
  injures 
  

   the 
  root. 
  This 
  insect 
  is 
  most 
  injurious 
  while 
  the 
  beets 
  are 
  young 
  and 
  is 
  

   destructive 
  only 
  in 
  the 
  larval 
  stage. 
  Other 
  beetles 
  occur 
  with 
  the 
  

   sugar-beet 
  wireworm, 
  e.g., 
  Drasterius 
  livens, 
  Lee, 
  Cardiophorus 
  aeneus, 
  

   Horn, 
  and 
  C. 
  crinitus 
  (?) 
  ; 
  Platynus 
  sp. 
  has 
  been 
  commonly 
  noted 
  and 
  

   also 
  Blapstinus 
  sp. 
  and 
  a 
  species 
  of 
  Cofiiontis. 
  Among 
  the 
  food-plants 
  

   recorded, 
  the 
  larvae 
  have 
  been 
  noted 
  on 
  wild 
  beet, 
  potato, 
  Lima 
  bean 
  

   (all 
  varieties), 
  maize 
  (all 
  varieties), 
  Johnson 
  grass 
  {Sorghum 
  halepense), 
  

   dock 
  (Rumex 
  hymenosepalus), 
  alfalfa 
  (Medicago 
  spp.),pigweed 
  {Amaran- 
  

   thus 
  retroflexus), 
  nettle, 
  wild 
  aster 
  and 
  Mustard 
  (Brassica 
  niger). 
  

   Oviposition 
  takes 
  place 
  during 
  the 
  spring, 
  mostly 
  in 
  April 
  ; 
  a 
  loose 
  

   damp 
  soil 
  is 
  selected 
  and 
  nearly 
  all 
  the 
  eggs 
  are 
  placed 
  in 
  the 
  top 
  inch 
  

   and 
  a 
  half 
  of 
  soil. 
  A 
  small 
  mite 
  Parasitus 
  (Gamasus) 
  coleoptratormn, 
  

   L., 
  was 
  commonly 
  observed 
  with 
  the 
  eggs. 
  Each 
  female 
  may 
  deposit 
  

   about 
  100 
  eggs, 
  and 
  these 
  hatch 
  in 
  about 
  15 
  to 
  25 
  days. 
  The 
  exact 
  

   length 
  of 
  the 
  larval 
  stage 
  is 
  not 
  known, 
  but 
  from 
  experiments 
  it 
  seems 
  

   that 
  it 
  could 
  not 
  be 
  less 
  than 
  three 
  years. 
  After 
  emerging 
  from 
  

   hibernation 
  the 
  wireworms 
  feed 
  on 
  the 
  old 
  beets 
  until 
  they 
  can 
  obtain 
  

   young 
  beets. 
  The 
  pupal 
  stage 
  lasts 
  for 
  about 
  a 
  month. 
  Old 
  beet- 
  

   roots 
  are 
  the 
  favourite 
  food, 
  and 
  the 
  larvae 
  are 
  only 
  occasionally 
  found 
  

   at 
  the 
  roots 
  of 
  alfalfa, 
  Johnson-grass, 
  wild 
  beets 
  and 
  young 
  beets. 
  In 
  

   the 
  experiments 
  recorded, 
  none 
  of 
  the 
  beetles 
  were 
  very 
  active 
  after 
  15 
  

   days, 
  and 
  after 
  25 
  days 
  they 
  became 
  very 
  feeble. 
  Under 
  field 
  condi- 
  

   tions 
  75° 
  F. 
  to 
  80° 
  F. 
  seems 
  to 
  be 
  the 
  optimum 
  temperature 
  for 
  their 
  

   various 
  activities, 
  and 
  most 
  adults 
  show 
  remarkable 
  ability 
  to 
  with- 
  

   stand 
  physical 
  injuries 
  or 
  sudden 
  and 
  unfavourable 
  climatic 
  conditions, 
  

   such 
  as 
  great 
  changes 
  in 
  temperature 
  and 
  several 
  severe 
  rainstorms 
  

   in 
  succession. 
  They 
  pass 
  the 
  severest 
  part 
  of 
  the 
  winter 
  in 
  the 
  soil 
  

   and 
  the 
  time 
  of 
  their 
  appearance 
  in 
  the 
  spring 
  is 
  influenced 
  to 
  a 
  large 
  

   extent 
  by 
  artificial 
  agencies 
  such 
  as 
  spring 
  ploughing. 
  Thus 
  pre- 
  

   maturely 
  driven 
  to 
  the 
  surface, 
  they 
  seek 
  " 
  secondary 
  hibernation 
  " 
  

   under 
  almost 
  any 
  shelter. 
  On 
  becoming 
  active 
  they 
  remain 
  relatively 
  

   near 
  the 
  hibernating 
  quarters, 
  but 
  are 
  disseminated 
  by 
  the 
  occurrence 
  

   of 
  strong 
  winds 
  and 
  floods. 
  

  

  The 
  wireworms 
  have 
  several 
  important 
  natural 
  checks. 
  Nearly 
  

   all 
  insectivorous 
  birds 
  eat 
  them, 
  and 
  the 
  Carabids 
  or 
  ground-beetles, 
  

   dispose 
  of 
  large 
  numbers. 
  The 
  adults 
  are 
  also 
  at 
  times 
  severely 
  

   attacked 
  by 
  a 
  fungous 
  disease. 
  No 
  efficient 
  parasite 
  has 
  yet 
  been 
  

   found 
  for 
  this 
  pest, 
  though 
  a 
  bacterial 
  disease 
  is 
  often 
  present. 
  On 
  

   the 
  whole, 
  the 
  larvae 
  of 
  L. 
  californicus 
  are 
  very 
  little 
  affected 
  by 
  their 
  

   animal 
  enemies, 
  or 
  by 
  fungous 
  or 
  bacterial 
  diseases. 
  

  

  Experiments 
  were 
  made 
  to 
  test 
  remedies 
  for 
  the 
  sugar-beet 
  wire- 
  

   worms. 
  Those 
  depending 
  upon 
  the 
  use 
  of 
  poisoned 
  bait 
  were 
  far 
  from 
  

  

  