﻿PROCEEDTIVGS 
  OF 
  THE 
  I'Ol'KlTr 
  ENTO.V!OLOGICAr> 
  MEETING 
  379 
  

  

  vities 
  of 
  Ciilicidse, 
  so 
  far 
  as 
  flights 
  are 
  concerned 
  (not 
  the 
  act 
  of 
  biting) 
  ; 
  

   Mr. 
  Howlett 
  tried 
  various 
  combinations 
  of 
  light 
  without 
  definite 
  results. 
  

  

  After 
  reading 
  Mr. 
  Howlett's 
  paper 
  on 
  Dacus 
  I 
  took 
  up 
  this 
  line 
  of 
  Mr. 
  Husaia. 
  

   work, 
  working 
  with 
  Dr. 
  Imms 
  at 
  Manchester 
  on 
  houseflics. 
  Our 
  joint 
  

   paper 
  appeared 
  in 
  the 
  Aymals 
  of 
  Applied 
  Biology. 
  We 
  found 
  that 
  their 
  

   response 
  to 
  baits 
  was 
  greatest 
  after 
  a 
  rainy 
  day, 
  so 
  presumably 
  humidity 
  

   increases 
  attraction. 
  

  

  There 
  has 
  been 
  a 
  practical 
  application 
  of 
  Mr. 
  Howlett's 
  line 
  of 
  w^ork 
  Mr. 
  Beeson. 
  

   in 
  American 
  Forests. 
  Dr. 
  Hopkinson, 
  dealing 
  with 
  polyphagous 
  bark 
  

   beetles, 
  found 
  that 
  there 
  was 
  a 
  tendency 
  for 
  a 
  species 
  mainly 
  feeding 
  

   on 
  one 
  species 
  of 
  tree, 
  to 
  get 
  its 
  habits 
  temporarily 
  fixed, 
  the 
  polyphagous 
  

   habit 
  being 
  temporarily 
  recessive. 
  This 
  was 
  applied 
  in 
  connection 
  

   with 
  epidemics 
  in 
  mixed 
  stands. 
  The 
  percentage 
  principle 
  was 
  applied 
  

   to 
  determine 
  the 
  species 
  of 
  tree 
  chiefly 
  attacked, 
  and 
  these 
  alone 
  v.'ere 
  

   removed. 
  Nothing 
  has 
  been 
  done 
  regarding 
  the 
  control 
  of 
  borers 
  by 
  

   the 
  attractive 
  principle 
  in 
  trees. 
  Forestry 
  has 
  been 
  practiced 
  for 
  a 
  

   hundred 
  years 
  in 
  Europe, 
  but 
  no 
  Entomologist 
  or 
  Chemist 
  knows 
  what 
  

   are 
  the 
  constituents 
  of 
  wood 
  and 
  bark 
  immediately 
  after 
  the 
  death 
  

   of 
  the 
  tree. 
  It 
  is 
  impossible 
  for 
  me 
  to 
  ask 
  our 
  Chemist 
  for 
  something 
  

   that 
  smells 
  like 
  a 
  dying 
  tree 
  of 
  any 
  particular 
  species. 
  In 
  the 
  Himalayan 
  

   turpentine 
  distilleries 
  no 
  borers 
  are 
  attracted, 
  and 
  therefore 
  the 
  turpen- 
  

   tine 
  in 
  the 
  tree 
  is 
  not 
  the 
  attractive 
  factor. 
  The 
  almost 
  automatic 
  

   response 
  of 
  insects 
  ta 
  stimuli 
  is 
  brought 
  out 
  prominently 
  by 
  sal 
  borer 
  

   work. 
  The 
  pupal 
  and 
  immature 
  imaginal 
  periods 
  are 
  directly 
  controlled 
  

   by 
  the 
  percentage 
  of 
  moisture 
  in 
  the 
  pupal 
  chamber, 
  which 
  varies 
  in 
  

   the 
  amount 
  of 
  moisture, 
  lost 
  by 
  the 
  wood 
  during 
  the 
  hot 
  weather. 
  A 
  

   long 
  " 
  hot 
  weather 
  " 
  results 
  in 
  delayed 
  initial 
  emergence 
  and 
  extended 
  

   emergence 
  period. 
  Early 
  rains 
  mean 
  an 
  early 
  initial 
  date 
  of 
  emergence 
  

   and 
  short 
  total 
  period. 
  By 
  this 
  we 
  can 
  regulate 
  the 
  storage 
  of 
  logs. 
  

  

  As 
  an 
  instance 
  of 
  delayed 
  emergence 
  owing 
  to 
  drying, 
  I 
  can 
  instance 
  ^^^ 
  Fletcher, 
  

   a 
  case 
  of 
  StroTnatium 
  barbatum 
  which 
  laid 
  eggs 
  in 
  the 
  insectary 
  in 
  1917, 
  

   and 
  the 
  larvae 
  are 
  still 
  living, 
  though 
  the 
  normal 
  life-cycle 
  is 
  about 
  two 
  

   years. 
  

  

  Stromatium 
  belongs 
  to 
  a 
  different 
  class 
  of 
  dry 
  heart-wood 
  borers. 
  Mr. 
  Beesou. 
  

   Its 
  normal 
  cycle 
  takes 
  four 
  years. 
  

  

  I 
  found 
  its 
  normal 
  cycle 
  to 
  be 
  two 
  years. 
  Mr. 
  Khare. 
  

  

  Mr. 
  Beeson 
  has 
  used 
  the 
  phrase 
  " 
  almost 
  automatic 
  response 
  to 
  Mr. 
  Fletcher, 
  

   external 
  conditions." 
  This 
  may 
  be 
  so 
  in 
  certain 
  cases, 
  but 
  is 
  not 
  a 
  

   general 
  one. 
  Four 
  years 
  ago 
  I 
  described 
  to 
  you 
  the 
  case 
  of 
  a 
  mudcell 
  

   building 
  wasp 
  which 
  showed 
  an 
  appreciation 
  of 
  novel 
  circumstances 
  

   and 
  exhibited 
  intelligence 
  rather 
  than 
  fixity 
  of 
  instinct. 
  

  

  