﻿PROCEEDINGS 
  OF 
  THE 
  FOURTH 
  ENTOMOLOGICAL 
  MEETING 
  145 
  

  

  hardly 
  found 
  but 
  later 
  on 
  they 
  multiply 
  and 
  in 
  October 
  and 
  November 
  

   they 
  increase 
  to 
  such 
  an 
  extent 
  that 
  this 
  borer 
  is 
  totally 
  annihilated 
  and 
  

   hardly 
  any 
  Chilo 
  caterpillars 
  are 
  found 
  in 
  the 
  stem. 
  In 
  the 
  year 
  1919, 
  

   owing 
  to 
  late 
  rains, 
  the 
  sowing 
  of 
  the 
  crop 
  was 
  delayed 
  so 
  the 
  percentage 
  

   of 
  borer 
  attack 
  in 
  the 
  crop 
  about 
  the 
  middle 
  of 
  August 
  varied 
  from 
  

   •25 
  per 
  cent, 
  to 
  1 
  per 
  cent, 
  which 
  increased 
  up 
  to 
  47 
  per 
  cent 
  in 
  some 
  

   plots 
  about 
  the 
  middle 
  of 
  September. 
  At 
  that 
  time 
  the 
  Tachinid 
  flv 
  

   parasites 
  were 
  not 
  sitting 
  silent. 
  They 
  were 
  also 
  trying 
  their 
  utmost 
  

   to 
  beat 
  the 
  borer 
  down 
  and 
  on 
  calculating 
  the 
  percentage 
  of 
  the 
  para- 
  

   sites 
  to 
  that 
  of 
  borers, 
  it 
  was 
  found 
  to 
  be 
  about 
  10 
  per 
  cent, 
  at 
  that 
  

   time, 
  which 
  increased 
  up 
  to 
  70 
  per 
  cent, 
  in 
  the 
  middle 
  of 
  October, 
  which 
  

   was 
  calculated 
  by 
  actually 
  splitting 
  open 
  the 
  affected 
  stems 
  and 
  taking 
  

   the 
  proportion 
  of 
  borers 
  to 
  that 
  of 
  the 
  parasites. 
  In 
  this 
  way, 
  in 
  the 
  

   later 
  stages 
  of 
  the 
  crop 
  this 
  borer 
  is 
  very 
  effectively 
  checked 
  by 
  these 
  

   parasites. 
  Trials 
  were 
  made 
  to 
  rear 
  and 
  breed 
  out 
  these 
  fly 
  parasites 
  

   on 
  a 
  large 
  scale 
  in 
  the 
  insectary, 
  and 
  for 
  that 
  proper 
  arrangements 
  

   were 
  made 
  to 
  feed 
  the 
  adult 
  flies 
  artificially 
  on 
  sugary 
  juice 
  ; 
  but 
  I 
  have 
  

   not 
  yet 
  succeeded 
  to 
  make 
  them 
  lay 
  eggs 
  on 
  their 
  hosts 
  in 
  a 
  rearing 
  

   cage, 
  for 
  which 
  further 
  trials 
  are 
  in 
  progress. 
  Another 
  difficulty 
  about 
  

   the 
  breeding 
  of 
  these 
  flies 
  is 
  that 
  they 
  cannot 
  be 
  reared 
  and 
  bred 
  out 
  

   in 
  winter 
  in 
  the 
  insectary 
  as 
  well 
  as 
  in 
  the 
  field. 
  

  

  Regarding 
  the 
  other 
  borer, 
  Sesamia, 
  the 
  caterpillars 
  of 
  which 
  begin 
  

   to 
  appear 
  in 
  the 
  more 
  advanced 
  stage 
  of 
  the 
  crop, 
  it 
  does 
  not 
  kill 
  the 
  

   plant 
  outright 
  like 
  the 
  first, 
  though 
  several 
  of 
  them 
  are 
  found 
  in 
  one 
  

   stalk 
  ; 
  however, 
  it 
  helps 
  to 
  decrease 
  the 
  yield 
  of 
  grain 
  in 
  ear-heads 
  by 
  

   making 
  them 
  small 
  and 
  bunchy 
  at 
  times. 
  It 
  usually 
  begins 
  from 
  

   September 
  and 
  breeds 
  on 
  till 
  the 
  crop 
  is 
  being 
  harvested, 
  then 
  it 
  goes 
  

   in 
  the 
  ofl'shoots 
  given 
  out 
  from 
  stumps 
  remaining 
  in 
  the 
  ground 
  where 
  

   it 
  breeds 
  even 
  in 
  summer. 
  During 
  the 
  severe 
  cold 
  of 
  winter 
  it 
  hiber- 
  

   nates 
  in 
  the 
  caterpillar 
  stage 
  in 
  stalks. 
  For 
  tackling 
  them 
  nothing 
  could 
  

   be 
  done 
  till 
  the 
  crop 
  is 
  being 
  harvested, 
  then 
  the 
  remaining 
  stalks 
  and 
  

   stumps 
  in 
  the 
  ground 
  could 
  be 
  dug 
  out 
  and 
  burnt 
  or 
  split 
  up 
  and 
  

   chaffed. 
  ^ 
  

  

  There 
  is 
  one 
  Braconid 
  parasite 
  which 
  preys 
  upon 
  these 
  caterpillars, 
  

   but 
  it 
  is 
  not 
  so 
  prolific 
  and 
  efficient 
  as 
  the 
  Tachinid 
  ; 
  so 
  the 
  best 
  way 
  of 
  

   controlling 
  this 
  borer 
  is 
  by 
  the 
  immediate 
  removal 
  of 
  stumps 
  remaining 
  

   in 
  the 
  ground 
  after 
  the 
  harvest 
  and 
  burning 
  them 
  to 
  put 
  a 
  stop 
  to 
  the 
  

   further 
  breeding 
  of 
  the 
  pest. 
  Further, 
  on 
  examining- 
  the 
  harvested 
  

   stalks 
  of 
  Sorghum, 
  it 
  was 
  observed 
  that 
  in 
  the 
  last 
  month 
  these 
  stalks 
  

   were 
  found 
  to 
  contain 
  the 
  Sesamia 
  borer, 
  attack 
  varying 
  from 
  7 
  per 
  

   cent, 
  to 
  30 
  per 
  cent. 
  

  

  