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  Haenel 
  (K.). 
  Angewandte 
  Entomologie 
  und 
  Vogelschutz. 
  [Applied 
  

   entomology 
  and 
  bird-protection.] 
  — 
  Zeitschr. 
  filr 
  angewandte 
  Ento- 
  

   mologie, 
  Berlin, 
  i, 
  no. 
  1, 
  April 
  1914, 
  pp. 
  214-222. 
  

  

  The 
  author 
  says 
  that 
  parasites 
  only 
  increase 
  when 
  their 
  hosts 
  are 
  

   numerous, 
  so 
  that 
  effective 
  parasitic 
  control 
  begins 
  when 
  the 
  injury 
  

   is 
  already 
  present, 
  but 
  that 
  birds, 
  which 
  do 
  not 
  confine 
  themselves 
  to 
  

   preying 
  on 
  given 
  species 
  of 
  insects, 
  will 
  multiply 
  at 
  all 
  times, 
  provided 
  

   that 
  other 
  conditions 
  are 
  suitable. 
  They, 
  therefore, 
  do 
  preventive 
  

   work, 
  while 
  the 
  action 
  of 
  parasites 
  is 
  curative. 
  (In 
  a 
  discussion 
  which 
  

   followed 
  this 
  address, 
  Prof. 
  Schwangart 
  pointed 
  out 
  that 
  useful 
  

   insects 
  are 
  unceasingly 
  doing 
  preventive 
  work.) 
  Insect 
  pests 
  are 
  

   usually 
  attacked 
  by 
  parasites 
  when 
  in 
  the 
  larval 
  stage, 
  but 
  birds 
  

   prey 
  on 
  all 
  stages. 
  Bird-protection 
  is, 
  therefore, 
  an 
  important 
  factor 
  

   in 
  the 
  biological 
  control 
  of 
  insect 
  pests, 
  though 
  it 
  is 
  difficult 
  to 
  produce 
  

   exact 
  statistics 
  of 
  the 
  good 
  work 
  they 
  do. 
  In 
  1912, 
  several 
  threatening 
  

   infestation 
  centres 
  of 
  Ijps 
  [Tomicus) 
  curvidens 
  appeared 
  near 
  

   Heinersreut, 
  in 
  Upper 
  Franconia, 
  but 
  large 
  numbers 
  of 
  spotted- 
  

   woodpeckers, 
  tits 
  and 
  nut-hatches 
  prevented 
  any 
  damage 
  being 
  done. 
  

   In 
  the 
  district 
  of 
  Fischstein, 
  when 
  investigating 
  an 
  attack 
  by 
  Dendroc- 
  

   tonus 
  micans 
  on 
  felled 
  timber, 
  the 
  author 
  noticed 
  that 
  in 
  wet 
  weather 
  

   these 
  beetles 
  prevented 
  the 
  water 
  from 
  running 
  into 
  their 
  galleries 
  

   by 
  placing 
  their 
  bodies 
  outwards 
  half-way 
  through 
  the 
  frass-holes. 
  

   In 
  this 
  position 
  they 
  were 
  seen 
  to 
  be 
  eaten 
  by 
  a 
  nut-hatch. 
  In 
  the 
  

   autumn 
  of 
  1909, 
  the 
  author 
  observed 
  two 
  stretches 
  of 
  copse, 
  adjoining 
  

   one 
  another, 
  both 
  of 
  which 
  contained 
  nun-moth 
  eggs, 
  one 
  being 
  twice 
  

   as 
  heavily 
  infested 
  as 
  the 
  other. 
  Bird-protection 
  was 
  carried 
  on 
  in 
  

   the 
  one, 
  while 
  its 
  less 
  threatened 
  neighbour 
  was 
  left 
  to 
  itself. 
  In 
  1910, 
  

   the 
  number 
  of 
  caterpillars 
  in 
  the 
  protected 
  area 
  was 
  only 
  one- 
  

   thousandth 
  that 
  of 
  the 
  eggs 
  observed, 
  while 
  in 
  the 
  other 
  wood 
  one- 
  

   tenth 
  of 
  the 
  eggs 
  had 
  hatched 
  out. 
  Dr. 
  Storp 
  reported 
  that 
  in 
  1908 
  

   nun-moth 
  pupae 
  in 
  enormous 
  numbers 
  on 
  the 
  Schnaken 
  estate 
  in 
  

   East 
  Prussia 
  were 
  attacked 
  by 
  swarms 
  of 
  starhngs, 
  which 
  in 
  two 
  or 
  

   three 
  days 
  destroyed 
  them 
  so 
  completely 
  that 
  sufficient 
  could 
  not 
  be 
  

   obtained 
  for 
  observation 
  purposes. 
  

  

  HoDGKiss 
  (H. 
  E.). 
  Susceptibility 
  to 
  Spraying 
  Mixtures 
  of 
  Hibernating 
  

   Pear 
  Psylla 
  Adults 
  and 
  their 
  Eggs. 
  — 
  New 
  York 
  Agric. 
  Expt. 
  Sta.^ 
  

   Geneva, 
  Bull. 
  no. 
  387, 
  May 
  1914, 
  pp. 
  389-418, 
  2 
  figs. 
  3 
  plates. 
  

  

  Owing 
  to 
  the 
  ineffectiveness 
  of 
  summer 
  spraying 
  as 
  a 
  control 
  

   measure 
  against 
  the 
  pear 
  psylla 
  nymphs, 
  this 
  station 
  has 
  been 
  investi- 
  

   gating 
  the 
  results 
  of 
  spraying 
  the 
  other 
  stages, 
  particularly 
  the 
  

   hibernating 
  adults 
  and 
  their 
  eggs. 
  The 
  variable 
  results 
  obtained 
  in 
  

   the 
  past 
  were 
  probably 
  due 
  to 
  the 
  influence 
  of 
  seasonal 
  conditions 
  on 
  

   the 
  habits 
  of 
  the 
  hibernating 
  adults. 
  It 
  was 
  observed 
  that 
  transfor- 
  

   mation 
  to 
  the 
  winter 
  adult 
  stage 
  took 
  place 
  in 
  late 
  September 
  or 
  

   early 
  October, 
  and 
  hibernation 
  occurred 
  on 
  all 
  varieties 
  of 
  pear 
  trees 
  

   and 
  to 
  a 
  less 
  extent 
  on 
  apple, 
  cherry, 
  peach 
  and 
  plum 
  trees, 
  when 
  these 
  

   were 
  near 
  infested 
  pear 
  trees 
  ; 
  harbourage 
  was 
  sometimes 
  provided 
  by 
  

   adjacent 
  outbuildings, 
  fences, 
  etc. 
  Two 
  tables 
  are 
  given 
  showing 
  that 
  

   these 
  wintering 
  adults 
  do 
  not 
  seek 
  protection 
  until 
  continued 
  freezing 
  

   temperatures 
  are 
  reached. 
  Thus 
  in 
  the 
  mild 
  winter 
  of 
  1913 
  few 
  

  

  (C67) 
  Wt. 
  P86 
  57. 
  1500. 
  9.14. 
  B.&F.Ltd. 
  Gp. 
  11/3. 
  k 
  

  

  