﻿SUBMERSION, 
  ETC. 
  ON 
  LARVAE 
  OF 
  CIMEX 
  LECTULARIUS. 
  

  

  115 
  

  

  wet 
  plaster 
  surface 
  (gypsum, 
  mixed 
  with 
  a 
  saturated 
  solution 
  of 
  CaH 
  2 
  0„) 
  so 
  that 
  they 
  

   were 
  partially 
  embedded. 
  All 
  were 
  found 
  to 
  be 
  attached. 
  13 
  hatched 
  == 
  52 
  per 
  cent. 
  

  

  Experiments 
  with 
  larval 
  bugs 
  in 
  1st 
  instar. 
  

  

  Cold 
  conditions 
  ; 
  unfed. 
  7 
  unfed 
  and 
  2 
  fed 
  larvae 
  were 
  kept 
  at 
  between 
  28° 
  and 
  

   32° 
  F. 
  for 
  2 
  days 
  ; 
  they 
  had 
  then 
  lost 
  power 
  of 
  movement. 
  After 
  half 
  an 
  hour 
  at 
  

   63° 
  F. 
  some 
  had 
  already 
  recovered 
  their 
  activity. 
  They 
  were 
  again 
  kept 
  at 
  between 
  

   28° 
  and 
  32° 
  F. 
  for 
  5 
  days 
  and 
  on 
  examination 
  were, 
  to 
  all 
  appearances, 
  dead, 
  but 
  after 
  

   4 
  hours 
  at 
  63° 
  F. 
  they 
  had 
  all 
  but 
  one 
  recovered 
  their 
  activity. 
  After 
  a 
  further 
  

   subjection 
  to 
  between 
  28° 
  and 
  32° 
  F. 
  for 
  25 
  days 
  they 
  were 
  kept 
  at 
  63 
  F., 
  but 
  no 
  

   recovery 
  took 
  place. 
  

  

  14 
  unfed 
  larvae 
  were 
  kept 
  at 
  between 
  28° 
  and 
  32° 
  F. 
  for 
  16 
  days 
  and 
  then 
  kept 
  at 
  

   63° 
  F. 
  ; 
  3 
  made 
  feeble 
  movements 
  after 
  2 
  hours, 
  6 
  were 
  active 
  after 
  24 
  hours, 
  and 
  

   10 
  were 
  active 
  after 
  48 
  hours. 
  The 
  remaining 
  4 
  made 
  no 
  movement, 
  but 
  were 
  prob- 
  

   ably 
  paralysed 
  rather 
  than 
  dead, 
  as 
  they 
  showed 
  no 
  signs 
  of 
  shrinkage 
  or 
  decay 
  

   after 
  96 
  hours, 
  while 
  their 
  limbs 
  reacted 
  slightly 
  to 
  touch 
  ; 
  9 
  of 
  the 
  10 
  that 
  recovered 
  

   were 
  alive 
  12 
  days 
  later. 
  

  

  Cold 
  conditions) 
  fed. 
  13 
  were 
  allowed 
  to 
  feed 
  on 
  human 
  blood 
  and 
  then 
  kept 
  in 
  an 
  

   entomological 
  box 
  at 
  between 
  28° 
  and 
  32° 
  F. 
  for 
  18 
  days. 
  They 
  were 
  then 
  transferred 
  

   to 
  63° 
  F. 
  Only 
  3 
  showed 
  any 
  signs 
  of 
  life 
  and 
  one 
  of 
  these 
  soon 
  died 
  ; 
  the 
  remaining 
  

   2 
  lived 
  for 
  15 
  days. 
  Of 
  these 
  13, 
  it 
  was 
  very 
  noticeable 
  that 
  all 
  those 
  which 
  fed 
  to 
  

   excess 
  failed 
  to 
  recover. 
  Of 
  the 
  3 
  which 
  revived 
  none 
  had 
  had 
  a 
  full 
  meal, 
  and 
  the 
  2 
  

   which 
  survived 
  longest 
  had 
  obtained 
  but 
  little 
  food. 
  Death 
  was 
  not, 
  I 
  think, 
  due 
  to 
  

   cold, 
  but 
  to 
  the 
  humidity 
  in 
  an 
  artificially 
  cooled 
  room. 
  Confinement 
  in 
  test-tubes, 
  

   even 
  when 
  crumpled 
  paper 
  is 
  given 
  for 
  a 
  foothold, 
  produces 
  a 
  high 
  mortality 
  among 
  

   young, 
  well-fed 
  bugs, 
  under 
  ordinary 
  laboratory 
  conditions 
  of 
  temperature 
  ; 
  while 
  

   confinement 
  in 
  card 
  boxes 
  under 
  similar 
  conditions 
  shows 
  no 
  death 
  rate. 
  Apparently 
  

   it 
  is 
  necessary 
  for 
  bugs 
  to 
  be 
  able 
  to 
  get 
  rid 
  of 
  superfluous 
  moisture 
  rapidly 
  after 
  a 
  

   heavy 
  meal, 
  and 
  this 
  is 
  inhibited 
  in 
  a 
  humid 
  atmosphere. 
  

  

  Moderate 
  conditions 
  ; 
  unfed. 
  38 
  unfed 
  larvae 
  hatched 
  at 
  60° 
  to 
  63° 
  F. 
  from 
  eggs 
  

   that 
  had 
  been 
  buried 
  for 
  4 
  days 
  in 
  dry 
  sand 
  at 
  between 
  43° 
  and 
  47° 
  F. 
  (see 
  

   experiment 
  page 
  114, 
  batch 
  (d) 
  ) 
  were 
  kept 
  in 
  the 
  laboratory 
  at 
  between 
  60° 
  and 
  

   65° 
  F., 
  and 
  afford 
  an 
  excellent 
  example 
  of 
  the 
  ability 
  of 
  this 
  pest 
  to 
  survive 
  unfed 
  

   under 
  favourable 
  conditions. 
  

  

  23 
  were 
  active 
  after 
  66 
  days 
  

  

  20 
  

   17 
  

   15 
  

   14 
  

   13 
  

   12 
  

   11 
  

  

  73 
  

  

  85 
  

  

  89 
  

  

  93 
  

  

  106 
  

  

  110 
  

  

  112 
  

  

  10 
  were 
  

  

  active 
  after 
  117 
  days 
  

  

  8 
  „ 
  

  

  (< 
  

  

  33 
  

  

  121 
  „ 
  

  

  7 
  „ 
  

  

  33 
  

  

  33 
  

  

  122 
  „ 
  

  

  6 
  „ 
  

  

  33 
  

  

  33 
  

  

  124 
  „ 
  

  

  5 
  „ 
  

  

  33 
  

  

  33 
  

  

  131 
  „ 
  

  

  4 
  „ 
  

  

  33 
  

  

  33 
  

  

  133 
  „ 
  

  

  3 
  „ 
  

  

  ( 
  

   3 
  

  

  33 
  

  

  136 
  „ 
  

  

  The 
  experiment 
  terminated 
  during 
  a 
  heat 
  wave, 
  when 
  the 
  laboratory 
  temperature 
  

   ™,s 
  over 
  70° 
  F. 
  

  

  was 
  over 
  70° 
  F. 
  

   <C53) 
  

  

  b2 
  

  

  