﻿Ill 
  

  

  THE 
  INFLUENCE 
  OF 
  TEMPERATURE, 
  SUBMERSION 
  AND 
  BURIAL 
  ON 
  THE 
  

  

  SURVIVAL 
  OF 
  EGGS 
  AND 
  LARVAE 
  OF 
  CIMEX 
  LECTULARIUS. 
  

  

  By 
  A. 
  W. 
  Bacot, 
  

  

  Entomologist 
  to 
  the 
  Lister 
  Institute. 
  

  

  These 
  experiments 
  were 
  performed 
  in 
  response 
  to 
  a 
  question 
  submitted 
  to 
  me 
  from 
  

   the 
  Royal 
  Sanitary 
  Institute. 
  The 
  point 
  at 
  issue 
  was 
  the 
  possibility 
  of 
  eggs 
  of 
  the 
  

   common 
  bed-bug, 
  Cimex 
  lectularius, 
  surviving 
  the 
  process 
  of 
  house-destruction, 
  

   when 
  the 
  plaster 
  from 
  old 
  walls, 
  on 
  which 
  eggs 
  had 
  been 
  laid, 
  was 
  broken 
  down 
  and 
  

   remixed 
  with 
  fresh 
  mortar 
  for 
  making 
  the 
  partitions 
  of 
  rooms 
  in 
  new 
  tenements 
  ; 
  

   such 
  survival 
  having 
  been 
  given 
  as 
  an 
  explanation 
  for 
  previously 
  unoccupied 
  houses 
  

   being 
  infested 
  with 
  bugs. 
  

  

  Methods. 
  

  

  The 
  ova 
  used 
  in 
  the 
  following 
  tests 
  were 
  obtained 
  by 
  placing 
  twenty 
  to 
  thirty 
  

   adult 
  specimens 
  of 
  C. 
  lectularius 
  in 
  a 
  lj-inch 
  glass-bottomed 
  entomological 
  box. 
  

   The 
  open 
  top 
  of 
  the 
  box 
  was 
  covered 
  with 
  fine 
  gauze, 
  through 
  which 
  the 
  bugs 
  were 
  

   allowed 
  to 
  feed 
  liberally 
  each 
  day. 
  When 
  feeding 
  was 
  not 
  in 
  progress 
  the 
  box 
  con- 
  

   taining 
  the 
  insects 
  was 
  kept 
  in 
  an 
  incubator 
  at 
  75°F. 
  A 
  slip 
  of 
  cloth 
  was 
  used 
  as 
  a 
  

   lining 
  to 
  the 
  box 
  to 
  afford 
  foothold. 
  As 
  the 
  great 
  majority 
  of 
  the 
  eggs 
  were 
  laid 
  on 
  

   the 
  cloth 
  this 
  plan 
  afforded 
  an 
  easy 
  means 
  of 
  dividing 
  up 
  batches 
  of 
  eggs 
  into 
  two 
  

   or 
  more 
  lots, 
  so 
  that 
  controls 
  could 
  be 
  obtained 
  without 
  any 
  disturbance 
  to 
  the 
  

   eggs. 
  In 
  order 
  to 
  get 
  large 
  numbers 
  for 
  some 
  of 
  the 
  experiments 
  the 
  eggs 
  were 
  in 
  

   certain 
  instances 
  allowed 
  to 
  accumulate 
  for 
  from 
  three 
  to 
  five 
  days 
  before 
  removal. 
  

  

  In 
  experiments 
  in 
  which 
  the 
  eggs 
  were 
  submerged 
  in 
  water 
  or 
  buried 
  in 
  sand, 
  those 
  

   laid 
  on 
  cloth 
  alone 
  were 
  used, 
  but 
  where 
  the 
  test 
  was 
  one 
  of 
  temperature 
  alone, 
  eggs 
  

   laid 
  on 
  the 
  sides 
  of 
  the 
  boxes 
  were 
  occasionally 
  utilised. 
  In 
  the 
  case 
  of 
  the 
  experiment 
  

   with 
  plaster 
  the 
  eggs 
  were 
  carefully 
  detached 
  from 
  the 
  sides 
  of 
  the 
  box 
  and 
  cloth 
  on 
  

   which 
  they 
  had 
  been 
  laid. 
  Control 
  eggs 
  were 
  always 
  taken 
  from 
  the 
  same 
  batch 
  as 
  

   those 
  experimented 
  with 
  and 
  all 
  control 
  eggs 
  were 
  kept 
  from 
  the 
  time 
  of 
  laying 
  in 
  

   an 
  incubator 
  at 
  75°F. 
  

  

  The 
  attached 
  table 
  shows 
  the 
  number 
  of 
  eggs 
  in 
  each 
  batch, 
  together 
  with 
  the 
  date 
  

   of 
  laying. 
  Batches 
  are 
  lettered 
  from 
  (a) 
  to 
  (r), 
  and 
  as 
  the 
  batch 
  letter 
  is 
  quoted 
  

   against 
  each 
  experiment, 
  it 
  is 
  possible 
  to 
  follow 
  the 
  history 
  and 
  find 
  the 
  percentage 
  

   hatching 
  in 
  different 
  portions 
  of 
  the 
  same 
  batch 
  which 
  were 
  subjected 
  to 
  different 
  

   conditions. 
  

  

  