﻿589 
  

  

  highest 
  percentage 
  of 
  parasitisation 
  for 
  each 
  species 
  concerned, 
  which 
  

   is 
  a 
  host, 
  the 
  observation 
  being 
  made 
  on 
  100 
  individuals 
  derived 
  from 
  

   the 
  same 
  batch 
  of 
  eggs. 
  Once 
  this 
  difficult 
  determination 
  has 
  been 
  

   made, 
  a 
  simple 
  calculation 
  shows 
  which 
  insects 
  should 
  be 
  encouraged 
  

   for 
  control 
  purposes. 
  

  

  Feytaud 
  (J.). 
  La 
  mortality 
  des 
  chrysalides 
  de 
  Cochylis 
  et 
  d'Eud^mis 
  

   pendant 
  I'hiver. 
  [Winter 
  mortahty 
  among 
  Clysia 
  and 
  Polychrosis 
  

   pupae.]— 
  i^ev. 
  Vitic, 
  xli, 
  no. 
  1066, 
  21st 
  May 
  1914, 
  pp. 
  573-575. 
  

  

  The 
  author 
  briefly 
  discusses 
  the 
  natural 
  enemies 
  of 
  Clysia 
  and 
  

   Polychrosis 
  and 
  tabulates 
  the 
  results 
  of 
  a 
  laboratory 
  investigation 
  of 
  

   the 
  mortahty 
  among 
  the 
  latter. 
  Batches 
  of 
  100 
  to 
  300 
  pupae 
  were 
  

   collected 
  at 
  five 
  different 
  locahties 
  and 
  the 
  following 
  figures 
  give 
  the 
  

   proportions 
  per 
  100 
  of 
  dead 
  Polychrosis, 
  viz. 
  : 
  — 
  87-1 
  — 
  90*1 
  — 
  75*0 
  — 
  

   93-2— 
  ^5-7. 
  The 
  causes 
  of 
  death 
  were 
  :— 
  Fungi, 
  57*9— 
  59'8 
  — 
  48-2— 
  

   47-5— 
  50-0; 
  Ichneumons, 
  21*8— 
  19 
  '0—13 
  -1—16 
  '9— 
  29-5 
  ; 
  predatory 
  

   enemies, 
  1'3— 
  8*1— 
  5 
  '0—20 
  •3—2-7 
  ; 
  various 
  enemies, 
  6-1— 
  3-2— 
  8*7— 
  

   8*5 
  — 
  3*5. 
  This 
  shows 
  the 
  mortality 
  to 
  have 
  been 
  severe 
  during 
  the 
  

   winter 
  of 
  1913-1914, 
  more 
  so 
  than 
  in 
  the 
  last 
  few 
  years. 
  Fungi 
  were 
  

   the 
  most 
  active 
  agents 
  owing 
  to 
  the 
  continued 
  heavy 
  rains 
  in 
  autumn. 
  

   The 
  frosts 
  do 
  not 
  appear 
  to 
  have 
  injured 
  the 
  hibernating 
  pupae 
  [see 
  

   this 
  Review, 
  Ser. 
  A, 
  ii, 
  p. 
  301], 
  but 
  their 
  enemies 
  which 
  are 
  active 
  in 
  

   winter 
  have 
  suffered 
  from 
  them. 
  For 
  instance, 
  the 
  larvae 
  of 
  Malachius, 
  

   abundant 
  during 
  the 
  preceding 
  winter 
  and 
  at 
  the 
  beginning 
  of 
  that 
  of 
  

   1913-1914, 
  were 
  rare 
  in 
  March 
  1914. 
  In 
  spite 
  of 
  the 
  heavy 
  mortaUty 
  

   shown 
  above, 
  preparations 
  must 
  be 
  made 
  for 
  control, 
  as 
  only 
  a 
  few 
  

   moths 
  of 
  the 
  first 
  generation 
  are 
  required 
  to 
  produce 
  numerous 
  larvae 
  

   in 
  June 
  and 
  August. 
  

  

  ScHAEFER 
  (A.). 
  Ueber 
  Pflanzenschutzmittel. 
  [Materials 
  for 
  plant 
  

   protection.] 
  — 
  Der 
  Obstzuchter, 
  no. 
  6, 
  1914. 
  Reprint, 
  3 
  pp. 
  

   [Received 
  24th 
  June 
  1914.] 
  

  

  The 
  author 
  disputes 
  the 
  efficiency 
  of 
  the 
  so-called 
  universal 
  controls 
  

   against 
  fungoid 
  diseases 
  and 
  insect 
  pests. 
  Remedies 
  advertised 
  for 
  

   use 
  against 
  individual 
  pests 
  should 
  only 
  be 
  used 
  if 
  tested 
  and 
  approved 
  

   by 
  a 
  competent 
  authority. 
  A 
  case 
  is 
  referred 
  to 
  where 
  a 
  product, 
  

   having 
  been 
  tested 
  and 
  found 
  useless, 
  was 
  then 
  advertised 
  by 
  the 
  

   maker 
  as 
  " 
  officially 
  tested." 
  A 
  third 
  class 
  comprises 
  such 
  products 
  

   as 
  " 
  carboHneum 
  " 
  and 
  " 
  bird-hme." 
  These 
  names 
  are 
  often 
  a 
  cloak 
  

   for 
  quite 
  useless 
  substances. 
  A 
  brand 
  of 
  bird-hme 
  which 
  had 
  given 
  

   good 
  results 
  up 
  to 
  a 
  certain 
  time, 
  eventually 
  proved 
  quite 
  unattractive 
  

   though 
  still 
  retaining 
  its 
  adhesive 
  character. 
  As 
  regards 
  carbohneum, 
  

   it 
  would 
  appear 
  that 
  any 
  waste 
  product 
  of 
  the 
  tar 
  industries 
  is 
  hable 
  

   to 
  be 
  sold 
  under 
  this 
  name. 
  A 
  further 
  class 
  includes 
  remedies 
  of 
  

   which 
  the 
  active 
  components 
  are 
  either 
  stated 
  by 
  the 
  maker 
  or 
  are 
  

   imphed 
  by 
  the 
  name, 
  such 
  as 
  Hme-sulphur 
  mixture. 
  When 
  purchasing 
  

   these 
  it 
  is 
  necessary 
  to 
  ascertain 
  whether 
  the 
  maker 
  guarantees 
  a 
  

   certain 
  percentage 
  of 
  the 
  active 
  ingredients, 
  and 
  an 
  independent 
  test 
  

   is 
  also 
  advisable, 
  as 
  a 
  substance 
  indicated 
  in 
  the 
  name 
  may 
  sometimes 
  

   be 
  entirely 
  absent. 
  Last 
  of 
  all 
  come 
  those 
  preparations 
  which 
  have 
  

  

  