﻿12.— 
  NOTES 
  ON 
  COTTON 
  WOOLLY 
  MITE 
  {ERIOPHYES 
  

  

  GOSSYPII). 
  

  

  By 
  T. 
  N. 
  Jhaveri, 
  L.Ag., 
  Entomological 
  Assistant, 
  Botnbaij. 
  

  

  These 
  mites 
  are 
  specially 
  more 
  prevalent 
  on 
  the 
  Herbaceum 
  variety 
  

   of 
  cotton 
  grown 
  in 
  Surat 
  and 
  Broach 
  Districts 
  of 
  Gujarat. 
  In 
  verna- 
  

   cular 
  this 
  disease 
  is 
  known 
  as 
  Clihasia 
  on 
  account 
  of 
  the 
  ash-like 
  appear- 
  

   ance 
  of 
  afEected 
  leaves. 
  In 
  a 
  year 
  of 
  drought 
  it 
  spreads 
  over 
  a 
  very 
  

   large 
  area, 
  and 
  checks 
  the 
  vigorous 
  growth 
  of 
  the 
  plant. 
  The 
  affected 
  

   leaves 
  remain 
  smaller 
  in 
  size 
  and 
  curl 
  up. 
  Later 
  on 
  in 
  December 
  and 
  

   January 
  the 
  disease 
  appears 
  to 
  be 
  checked 
  and 
  the 
  plant 
  becomes 
  some- 
  

   what 
  healthier, 
  which 
  is 
  believed 
  due 
  to 
  the 
  falling 
  of 
  dew 
  in 
  winter. 
  

  

  These 
  mites 
  are 
  very 
  microscopic 
  and 
  not 
  readily 
  visible 
  to 
  the 
  naked 
  

   eye. 
  They 
  mostly 
  live 
  under 
  the 
  tissues 
  of 
  the 
  epidermis 
  of 
  the 
  leaf 
  and 
  

   cause 
  a 
  growth 
  of 
  dense 
  whitish 
  hairs, 
  on 
  the 
  upper 
  and 
  lower 
  surface 
  

   of 
  leaves 
  as 
  well 
  as 
  on 
  stems. 
  This 
  whitish 
  growth 
  is 
  due 
  to 
  the 
  formation 
  

   of 
  hairs 
  from 
  the 
  epidermal 
  tissue 
  of 
  leaves 
  and 
  stems 
  brought 
  about 
  by 
  

   the 
  irritation 
  of 
  these 
  mites. 
  

  

  Later 
  on 
  in 
  the 
  advanced 
  stage 
  of 
  the 
  crop 
  small 
  tiny 
  predaceous 
  

   grubs 
  of 
  Coccinellid 
  beetles 
  are 
  noticed 
  in 
  the 
  colonies 
  of 
  these 
  mites. 
  

   These 
  are 
  also 
  small 
  and 
  somewhat 
  elongated 
  and 
  of 
  a 
  pale 
  rosy 
  colour. 
  

  

  On 
  carefully 
  examining 
  them 
  under 
  a 
  lens 
  these 
  are 
  seen 
  to 
  move 
  

   actively 
  inside 
  the 
  meshes 
  and 
  to 
  toss 
  their 
  head 
  here 
  and 
  there 
  in 
  search 
  

   of 
  their 
  prey. 
  

  

  Wherever 
  the 
  presence 
  of 
  these 
  grubs 
  is 
  noticed, 
  the 
  colonies 
  of 
  mites 
  

   gradually 
  dwindle 
  away 
  and 
  the 
  white 
  fluffy 
  growths 
  of 
  the 
  epidermal 
  

   tissues 
  of 
  leaves 
  turn 
  pale 
  yellow 
  and 
  appear 
  to 
  dry 
  up. 
  

  

  As 
  for 
  the 
  control 
  measure 
  of 
  the 
  pest 
  some 
  trials 
  were 
  made. 
  In 
  

   the 
  year 
  1917 
  towards 
  Khandesh 
  side, 
  where 
  the 
  Neglectum 
  type 
  of 
  

   cotton 
  is 
  grown 
  and 
  rarely 
  these 
  mites 
  are 
  found 
  in 
  any 
  appreciable 
  

   amount, 
  there 
  they 
  appeared 
  rather 
  in 
  a 
  severe 
  form 
  in 
  that 
  year. 
  The 
  

   reason 
  for 
  that 
  appeared 
  to 
  be 
  that, 
  in 
  that 
  year 
  they 
  had 
  a 
  very 
  long 
  

   break 
  in 
  the 
  rains 
  for 
  nearly 
  two 
  months 
  in 
  July 
  and 
  August 
  which 
  

   caused 
  the 
  plants 
  to 
  suffer 
  too 
  much 
  from 
  drought. 
  In 
  that 
  year, 
  some 
  

   experiments 
  of 
  topping 
  and 
  irrigation 
  were 
  made 
  in 
  a 
  cultivator's 
  field 
  

   at 
  Ner, 
  District 
  Dhulia. 
  On 
  examining 
  the 
  crop 
  in 
  the 
  month 
  of 
  Septem- 
  

   ber, 
  it 
  was 
  noticed 
  that 
  those 
  plants, 
  whose 
  tops 
  were 
  nipped 
  ofi 
  to 
  

  

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  96 
  ) 
  

  

  