﻿162 
  PROCEEDINGS 
  OF 
  THE 
  FOURTH 
  ENTOMOLOGICAL 
  MEETING 
  

  

  heavy 
  left 
  hand 
  vertical 
  line 
  represents 
  the 
  number 
  of 
  days 
  (pupal 
  

   stage) 
  and 
  the 
  right 
  hand 
  one, 
  temperature. 
  This 
  temperature 
  is 
  not 
  

   absolute 
  but 
  is 
  the 
  mean 
  of 
  the 
  maximum 
  temperatures 
  for 
  14 
  days 
  

   previous 
  to 
  the 
  emergence 
  of 
  the 
  adult 
  parasite, 
  to 
  which 
  a 
  cocoon 
  has 
  

   been 
  exposed. 
  The 
  vertical 
  lines 
  A. 
  B. 
  C, 
  etc., 
  representing 
  each 
  one 
  

   cocoon, 
  have 
  on 
  them 
  shown 
  lengths 
  of 
  the 
  pupal 
  stages 
  of 
  the 
  

   different 
  cocoons 
  and 
  their 
  corresponding 
  temperature. 
  It 
  has 
  further 
  

   been 
  seen 
  that 
  when 
  the 
  emergence 
  stopped 
  for 
  some 
  cocoons 
  on 
  

   account 
  of 
  the 
  rise 
  of 
  temperature 
  above 
  85°F. 
  the 
  functional 
  activity 
  

   of 
  the 
  pupse 
  may 
  be 
  revived 
  even 
  after 
  two 
  months, 
  if 
  they 
  are 
  

   again 
  placed 
  under 
  favourable 
  temperature 
  conditions 
  {i.e., 
  below 
  

   80°F.). 
  It 
  shows 
  that 
  any 
  rise 
  of 
  temperature 
  above 
  80°F. 
  if 
  it 
  is 
  

   too 
  high, 
  only 
  arrests 
  the 
  development 
  temporarily, 
  but 
  the 
  vitality 
  is 
  

   not 
  lost 
  as 
  it 
  may 
  again 
  be 
  revived 
  by 
  reintroducing 
  the 
  favourable 
  

   conditions. 
  So 
  far, 
  therefore, 
  as 
  temperature 
  is 
  concerned 
  it 
  has 
  been 
  

   found 
  possible, 
  by 
  regulating 
  it, 
  to 
  make 
  the 
  parasite 
  pupae 
  or 
  grubs 
  

   emerge 
  as 
  adults, 
  at 
  any 
  desired 
  time, 
  provided 
  of 
  coarse 
  due 
  time 
  allow- 
  

   ance 
  is 
  given 
  to 
  the 
  sestivating 
  parasite 
  by 
  way 
  of 
  exposure 
  to 
  favour- 
  

   able 
  temperature 
  conditions. 
  Now 
  it 
  remains 
  to 
  find 
  out 
  how 
  best 
  it 
  is 
  

   possible 
  to 
  force 
  the 
  parasite 
  cocoons 
  to 
  become 
  dormant, 
  i.e., 
  to 
  get 
  into 
  

   aestivation. 
  This 
  may 
  probably 
  be 
  accomplished 
  by 
  exposing 
  them 
  

   to 
  continued 
  low 
  temperature 
  much 
  below 
  53°F. 
  but 
  since 
  it 
  is 
  not 
  

   economical 
  to 
  maintain 
  it 
  for 
  several 
  months, 
  it 
  has 
  been 
  found 
  necessary 
  

   to 
  handle 
  the 
  problem 
  by 
  modifying 
  humidity 
  which 
  is 
  more 
  easy 
  to 
  

   control 
  than 
  temperature. 
  An 
  experunent 
  on 
  this 
  line 
  is 
  at 
  present 
  being 
  

   conducted 
  but 
  it 
  has 
  not 
  been 
  completed 
  yet. 
  From 
  this 
  experiment 
  it 
  

   was 
  been 
  seen 
  that 
  when 
  a 
  freshly 
  formed 
  cocoon 
  is 
  kept 
  in 
  a 
  vessel 
  

   maintaining 
  a 
  constant 
  Relative 
  Humidity 
  of 
  5°, 
  it 
  becomes 
  dormant. 
  

   Adult 
  insects 
  emerged 
  from 
  a 
  check 
  lot 
  of 
  the 
  same 
  batch 
  of 
  cocoons 
  in 
  

   15 
  days 
  but 
  the 
  treated 
  cocoons 
  on 
  being 
  taken 
  out 
  of 
  the 
  vessel 
  after 
  two 
  

   months 
  were 
  on 
  examination 
  found 
  to 
  be 
  still 
  living 
  as 
  healthy 
  grubs 
  

   within 
  the 
  cocoons 
  in 
  a 
  dormant 
  condition. 
  Trials 
  are 
  at 
  present 
  being 
  

   made 
  to 
  revive 
  them 
  and 
  make 
  them 
  emerge 
  as 
  adults 
  under 
  favourable 
  

   humid 
  conditions. 
  If 
  this 
  proves 
  successful 
  the 
  problem 
  of 
  utiHzing 
  

   this 
  parasite 
  as 
  a 
  means 
  of 
  control 
  will 
  resolve 
  itself 
  into 
  :— 
  

  

  (1) 
  Collection 
  of 
  parasite 
  cocoons 
  from 
  the 
  affected 
  area 
  in 
  February 
  

  

  and 
  March 
  when 
  they 
  are 
  common 
  there 
  or 
  to 
  breed 
  them 
  

   out 
  in 
  the 
  Insectary 
  in 
  large 
  numbers 
  in 
  winter, 
  when 
  both 
  

   the 
  host 
  and 
  parasite 
  are 
  active 
  and 
  to 
  enforce 
  dormancy 
  

   on 
  them 
  by 
  placing 
  them 
  under 
  proper 
  dry 
  conditions 
  and 
  

  

  (2) 
  to 
  make 
  the 
  adults 
  emerge 
  from 
  the 
  dormant 
  cocoons 
  in 
  Septem- 
  

  

  ber 
  or 
  October 
  by 
  exposing 
  the 
  whole 
  lot 
  of 
  them, 
  in 
  due 
  

   time, 
  to 
  favourable 
  temperature 
  conditions. 
  

  

  