﻿42 
  

  

  THE 
  BEAN 
  THKIPS. 
  

  

  the 
  bean 
  thrips, 
  and 
  in 
  confinement 
  larvae 
  were 
  observed 
  to 
  kill 
  and 
  

   eat 
  large 
  numbers 
  of 
  the 
  host. 
  

  

  The 
  young 
  of 
  Triphleps 
  insidiosus 
  Say 
  were 
  noticed 
  on 
  many 
  

   occasions 
  feeding 
  on 
  the 
  young 
  of 
  this 
  thrips 
  and 
  undoubtedly 
  aid 
  

   in 
  reducing 
  its 
  numbers. 
  

  

  The 
  larvae 
  and 
  adults 
  of 
  Hippodamia 
  con 
  ver 
  gens 
  Guer 
  were 
  fre- 
  

   quently 
  collected 
  on 
  plants 
  infested 
  with 
  thrips, 
  where 
  they 
  were 
  

   busily 
  engaged 
  in 
  feasting 
  on 
  the 
  tender 
  larvae 
  of 
  the 
  bean 
  thrips. 
  

  

  On 
  several 
  occasions 
  larvae 
  of 
  a 
  predaceous 
  thrips, 
  probably 
  /Eolo- 
  

   t 
  /trips 
  fasciatus 
  L., 
  when 
  collected 
  were 
  feeding 
  on 
  the 
  larvae 
  of 
  the 
  

   bean 
  thrips. 
  

  

  Fig. 
  11. 
  — 
  A 
  hymenopterous 
  parasite, 
  Thripoctenus 
  russelli: 
  Adult. 
  

  

  (Author's 
  illustration. 
  ) 
  

  

  Greatly 
  enlarged. 
  

  

  Mr. 
  P. 
  E. 
  Jones 
  informed 
  the 
  writer 
  that 
  at 
  Lindsay, 
  Cal., 
  in 
  

   1910, 
  he 
  found 
  a 
  "nematode 
  parasite 
  working 
  in 
  the 
  full-grown 
  

   larvae 
  of 
  the 
  bean 
  thrips." 
  

  

  A 
  curious 
  circumstance 
  in 
  connection 
  with 
  the 
  observations 
  made 
  

   on 
  the 
  natural 
  enemies 
  of 
  the 
  bean 
  thrips 
  was 
  the 
  fact 
  that 
  in 
  all 
  of 
  

   the 
  predaceous 
  forms 
  noted 
  the 
  alimentary 
  tract 
  became 
  bright 
  red, 
  

   undoubtedly 
  due 
  to 
  the 
  crimson 
  or 
  reddish 
  pigmentation 
  of 
  the 
  host. 
  

  

  ARTIFICIAL 
  CONTROL. 
  

  

  CULTURAL 
  METHODS. 
  

  

  In 
  the 
  case 
  of 
  crops 
  planted 
  over 
  large 
  areas 
  and 
  difficult 
  or 
  im- 
  

   possible 
  to 
  spray, 
  such 
  as 
  beans, 
  alfalfa, 
  or 
  cotton, 
  cultural 
  methods 
  

   offer 
  the 
  most 
  hope 
  as 
  a 
  remedy 
  for 
  the 
  bean 
  thrips. 
  Where 
  this 
  

   insect 
  threatens 
  injury 
  it 
  is 
  recommended 
  that 
  these 
  methods 
  be 
  used 
  

   so 
  far 
  as 
  possible. 
  It 
  is 
  very 
  important 
  that 
  the 
  crops 
  be 
  given 
  

  

  