﻿13.— 
  NOTES 
  ON 
  "KATRA'' 
  (HAIRY 
  CATERPILLARS) 
  AND 
  

   THEIR 
  CONTROLLING 
  MEASURES. 
  

  

  By 
  T. 
  N. 
  Jhaveei, 
  L.Aa., 
  Entomological 
  Assistant, 
  Bombay. 
  

  

  The 
  species 
  which 
  is 
  so 
  prevalent 
  in 
  N. 
  Gujarat 
  is 
  Amsacta 
  moorei. 
  

   It 
  seems 
  to 
  have 
  taken 
  a 
  firm 
  hold 
  in 
  certain 
  tracts 
  of 
  the 
  light 
  Goradu 
  

   soil 
  and 
  appears 
  to 
  move 
  slowly 
  from 
  west 
  to 
  east, 
  that 
  is, 
  towards 
  the 
  

   prevailing 
  direction 
  of 
  the 
  wind 
  in 
  the 
  beginning 
  of 
  the 
  monsoon. 
  

  

  Regarding 
  the 
  habits 
  of 
  the 
  pest, 
  it 
  has 
  been 
  noticed 
  that 
  they 
  are 
  

   usually 
  not 
  found 
  to 
  breed 
  and 
  appear 
  as 
  pest 
  in 
  the 
  tracts 
  of 
  heavy 
  

   black 
  soil. 
  This, 
  I 
  thinlc, 
  is 
  mainly 
  due 
  to 
  the 
  unfavomabl^ 
  condition 
  

   of 
  the 
  soil 
  produced 
  by 
  natural 
  heavy 
  cracking 
  of 
  the 
  soil 
  surface 
  dming 
  

   summer, 
  as 
  well 
  as 
  by 
  more 
  retension 
  of 
  moisture 
  dming 
  rainy 
  days. 
  

   In 
  the 
  tract 
  where 
  this 
  pest 
  appears 
  as 
  a 
  pest, 
  their 
  moths 
  begin 
  to 
  emerge 
  

   from 
  their 
  hibernating 
  pupse 
  in 
  soil, 
  in 
  the 
  beginning 
  of 
  the 
  early 
  favour- 
  

   able 
  monsoon. 
  By 
  this 
  I 
  mean 
  about 
  8 
  inches 
  of 
  good 
  rain 
  in 
  the 
  first 
  

   week 
  of 
  June 
  and 
  soaking 
  of 
  the 
  soil 
  to 
  a 
  depth 
  of 
  about 
  4 
  inches 
  or 
  so. 
  

   If 
  the 
  monsoon 
  is 
  delayed 
  for 
  about 
  three 
  weeks 
  or 
  a 
  month, 
  the 
  emer- 
  

   gence 
  of 
  moths 
  is 
  not 
  very 
  hea^7 
  in 
  that 
  year. 
  At 
  the 
  same 
  time 
  early 
  

   rains 
  in 
  May 
  are 
  also 
  not 
  favourable 
  for 
  the 
  successful 
  emergence 
  of 
  these 
  

  

  moths. 
  

  

  The 
  time 
  of 
  greatest 
  emergence 
  of 
  these 
  moths 
  is 
  chiefly 
  at 
  night 
  till 
  

   midnight 
  during 
  the 
  break 
  and 
  partly 
  in 
  the 
  evening 
  and 
  rarely 
  during 
  

   the 
  day. 
  This 
  continues 
  for 
  about 
  a 
  week 
  or 
  twelve 
  days 
  depending 
  

   upon 
  the 
  break 
  in 
  rains 
  and 
  they 
  are 
  greatly 
  attracted 
  to 
  burning 
  lamps 
  

   and 
  lights 
  at 
  night. 
  

  

  The 
  distinction 
  of 
  sexes 
  is 
  rather 
  easy 
  in 
  this 
  case. 
  The 
  female 
  is 
  

   ^ 
  inches 
  lon^^, 
  bigger 
  and 
  thicker 
  in 
  size 
  with 
  a 
  distinct 
  round 
  fleshy 
  

   ball 
  at 
  the 
  orifice 
  of 
  the 
  generative 
  organ, 
  which 
  is 
  absent 
  in 
  males. 
  

   The 
  male 
  is 
  about 
  half-an-inch 
  long, 
  lean 
  and 
  small 
  in 
  size, 
  with 
  a 
  slight 
  

   projection 
  of 
  the 
  last 
  anal 
  segment. 
  After 
  emerging, 
  the 
  couples 
  unite 
  

   and 
  a 
  female 
  moth 
  lays 
  about 
  700 
  eggs 
  in 
  clusters 
  of 
  200 
  to 
  300 
  on 
  the 
  

   seedlinc^s 
  of 
  the 
  early 
  sown 
  crops 
  or 
  their 
  favourite 
  weeds 
  and 
  hedge 
  

   plants." 
  These 
  eggs 
  hatch 
  in 
  a 
  period 
  of 
  three 
  to 
  four 
  days. 
  The 
  young 
  

   tiny 
  caterpillars 
  remain 
  feeding 
  on 
  their 
  food 
  plants 
  for 
  a 
  period 
  of 
  about 
  

   four 
  days, 
  thereafter 
  they 
  scatter 
  and 
  devour 
  the 
  crops 
  and 
  weeds 
  which 
  

   come 
  in 
  their 
  way. 
  In 
  this 
  way 
  they 
  become 
  fullgrown 
  in 
  a 
  period 
  of 
  

   about 
  20 
  to 
  24 
  days 
  and 
  the 
  size 
  of 
  a 
  fullgrown 
  caterpillar 
  measiu-es 
  up 
  

  

  ( 
  9S 
  ) 
  

  

  