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  TEOCEEDINGS 
  OF 
  THE 
  FOURTH 
  EIsTOMOLOGICAL 
  MEETING 
  

  

  When 
  the 
  bolls 
  appear, 
  they 
  attack 
  them. 
  They 
  sometimes 
  feed 
  

   exposed 
  but 
  generally 
  they 
  lead 
  the 
  life 
  of 
  a 
  borer, 
  boring 
  into 
  shoots, 
  

   vegetative 
  buds, 
  floral 
  buds, 
  and 
  bolls. 
  

  

  Although 
  it 
  is 
  premature 
  at 
  the 
  present 
  stage 
  of 
  our 
  knowledge 
  to 
  

   express 
  any 
  view 
  as 
  to 
  the 
  efficacy 
  of 
  Microhracon 
  as 
  a 
  check 
  against 
  

   Earias 
  yet 
  it 
  will 
  not 
  be 
  out 
  of 
  place 
  to 
  discuss 
  the 
  question 
  in 
  the 
  light 
  

   of 
  "what 
  is 
  already 
  known. 
  

  

  Fletcher(o) 
  is 
  doubtful 
  whether 
  Microhracon 
  can 
  be 
  an 
  effective 
  

   check 
  against 
  the 
  bollworms, 
  because 
  the 
  percentage 
  of 
  parasites' 
  in 
  

   the 
  specially 
  looked 
  after 
  parasitic 
  plot 
  at 
  Pusa 
  is 
  too 
  low 
  — 
  12 
  per 
  cent. 
  

   There 
  are, 
  however, 
  certain 
  facts 
  that 
  are 
  significant. 
  So 
  far 
  as 
  is 
  known, 
  

   Microhracon 
  is 
  singularly 
  free 
  from 
  enemies, 
  parasites 
  and 
  predators, 
  

   and 
  it 
  lays 
  a 
  sufficiently 
  large 
  number 
  of 
  eggs. 
  It 
  therefore 
  has 
  great 
  

   possibilities 
  of 
  rapid 
  multiplication. 
  

  

  The 
  life-cycle 
  of 
  Microhracon 
  takes 
  only 
  ten 
  days 
  in 
  summer 
  as 
  com- 
  

   pared 
  to 
  30 
  days 
  of 
  Earias 
  and 
  assuming 
  that 
  a 
  female 
  Microhracon 
  

   lays 
  only 
  100 
  eggs, 
  only 
  50 
  of 
  which 
  develop 
  into 
  females, 
  and 
  assuming 
  

   on 
  the 
  other 
  hand 
  that 
  the 
  bollworm 
  lays 
  500 
  eggs, 
  50 
  per 
  cent, 
  deve- 
  

   loping 
  into 
  females, 
  and 
  assuming 
  that 
  in 
  both 
  cases 
  other 
  factors 
  are 
  

   the 
  same, 
  the 
  progeny 
  of 
  one 
  pair 
  of 
  Microhracon 
  will 
  be 
  able 
  to 
  kill 
  

   off 
  the 
  progeny 
  of 
  500 
  pairs 
  of 
  Earias 
  in 
  the 
  30 
  days' 
  time 
  taken 
  by 
  

   one 
  generation 
  of 
  the 
  bollworm. 
  Theoretically, 
  therefore, 
  the 
  probabi- 
  

   lity 
  of 
  checking 
  Earias 
  by 
  the 
  use 
  of 
  their 
  parasite 
  seem 
  to 
  be 
  within 
  

   the 
  range 
  of 
  practicability. 
  

  

  Before 
  we 
  are 
  able 
  to 
  give 
  an 
  effective 
  help 
  to 
  Microhracon 
  in 
  its 
  

   fight 
  against 
  bollworm 
  we 
  must 
  be 
  able 
  to 
  domesticate 
  it, 
  and 
  liberate 
  

   it 
  in 
  the 
  beginning 
  of 
  the 
  season 
  in 
  very 
  large 
  numbers. 
  

  

  Table 
  No. 
  1. 
  

   Daily 
  rate 
  of 
  oviposition 
  of 
  Microhracon 
  lefroyi. 
  1920. 
  

  

  