﻿685 
  

  

  but 
  only 
  for 
  a 
  short 
  time. 
  As 
  the 
  weather 
  grows 
  colder 
  their 
  move- 
  

   ments 
  become 
  more 
  limited 
  and 
  by 
  the 
  end 
  of 
  December 
  they 
  appear 
  

   only 
  to 
  crawl 
  out 
  for 
  warmth. 
  These 
  migrants, 
  which 
  seem 
  to 
  be 
  all 
  

   primary 
  larvae, 
  appear 
  to 
  have 
  a 
  natural 
  tendency 
  to 
  mount 
  either 
  

   on 
  higher 
  ground 
  or 
  on 
  the 
  vine 
  branches 
  ; 
  they 
  are, 
  under 
  favourable 
  

   conditions, 
  carried 
  some 
  distance 
  by 
  the 
  wind, 
  but 
  are 
  so 
  easily 
  pro- 
  

   tected 
  by 
  stones, 
  bits 
  of 
  earth, 
  etc., 
  on 
  the 
  surface, 
  that 
  this 
  is 
  of 
  no 
  real 
  

   importance, 
  though 
  violent 
  winds 
  may 
  carry 
  away 
  large 
  numbers. 
  

   The 
  resistance 
  of 
  these 
  larvae 
  to 
  heat, 
  cold, 
  moisture 
  and 
  other 
  weather 
  

   conditions 
  has 
  been 
  studied. 
  Their 
  resistance 
  to 
  heat 
  increases 
  as 
  the 
  

   season 
  advances 
  and 
  rain 
  begins 
  to 
  fall. 
  For 
  example, 
  in 
  July, 
  when 
  

   the 
  sun 
  is 
  hot 
  and 
  the 
  soil 
  dry, 
  they 
  will 
  only 
  survive 
  exposure 
  for 
  a 
  

   very 
  short 
  time, 
  whereas 
  if 
  the 
  soil 
  be 
  moist, 
  they 
  survive 
  for 
  three 
  or 
  

   four 
  hours 
  ; 
  in 
  southern 
  Italy 
  the 
  dry 
  heat 
  causes 
  a 
  great 
  diminution 
  

   of 
  migration 
  in 
  July 
  and 
  August. 
  In 
  those 
  months 
  in 
  which 
  the 
  heat 
  

   is 
  not 
  too 
  intense 
  and 
  some 
  rain 
  falls, 
  the 
  danger 
  of 
  transport 
  of 
  

   Phylloxera 
  hj 
  people 
  working 
  in 
  the 
  vineyards 
  is 
  considerable 
  and 
  it 
  

   would 
  apparently 
  be 
  wise 
  not 
  to 
  carry 
  out 
  any 
  operations 
  in 
  vineyards 
  

   in 
  windy 
  weather. 
  Winter 
  digging, 
  according 
  to 
  Tramoni, 
  is 
  dangerous, 
  

   as 
  the 
  insects 
  are 
  carried 
  by 
  the 
  spades 
  and 
  hoes, 
  but 
  this 
  is 
  not 
  the 
  

   case 
  in 
  May. 
  Fragments 
  of 
  small 
  roots 
  bearing 
  hibernating 
  colonies 
  

   are 
  frequently 
  carried 
  on 
  tools 
  in 
  winter, 
  especially 
  when 
  the 
  soil 
  has 
  

   been 
  disturbed 
  to 
  some 
  depth. 
  

  

  Commercial 
  pyridin 
  as 
  a 
  vine 
  pest 
  control. 
  — 
  Jl. 
  Agric. 
  pratique, 
  Paris, 
  

   xxviii, 
  no. 
  30, 
  23rd 
  July 
  1914, 
  p. 
  129. 
  

   Commercial 
  pyridin 
  acts 
  as 
  an 
  insectifuge 
  against 
  the 
  adults 
  of 
  

   Polychrosis 
  botrana 
  and 
  as 
  a 
  contact 
  poison 
  against 
  the 
  larvae. 
  A 
  1| 
  

   per 
  cent, 
  solution 
  is 
  non-injurious 
  to 
  the 
  vine 
  in 
  summer, 
  though 
  it 
  

   may 
  scorch 
  the 
  inflorescences. 
  Its 
  effect 
  only 
  lasts 
  for 
  two 
  days, 
  so 
  

   that 
  frequent 
  apphcations 
  are 
  necessary 
  whilst 
  the 
  moths 
  are 
  on 
  the 
  

   wing 
  or 
  the 
  larvae 
  are 
  hatching. 
  Black 
  soap 
  increases 
  the 
  efficacy 
  

   of 
  pyridin 
  and 
  the 
  following 
  solution 
  is 
  fatal 
  to 
  the 
  larvae 
  : 
  Pyridin 
  

   2 
  oz., 
  black 
  soap 
  1| 
  oz., 
  water 
  100 
  oz. 
  In 
  association 
  with 
  Burgundy 
  

   mixture, 
  its 
  insecticidal 
  value 
  is 
  inferior 
  to 
  that 
  of 
  nicotin. 
  Pyridin 
  

   oleate 
  appears 
  to 
  have 
  a 
  more 
  lasting 
  effect, 
  as 
  it 
  wets 
  the 
  leaves 
  well 
  

   and 
  acts 
  as 
  a 
  direct 
  insecticide. 
  

  

  Semichon 
  (L.). 
  Destruction 
  des 
  insectes 
  et 
  des 
  cryptogames. 
  Nou- 
  

   veaux 
  proc6d6s. 
  [New 
  methods 
  for 
  destroying 
  insects 
  and 
  

   fungi.]— 
  i^ev. 
  Vitic, 
  Paris, 
  xHi, 
  no. 
  1076, 
  '30th 
  July 
  19U, 
  

   pp. 
  113-120. 
  

   If 
  properly 
  handled, 
  purely 
  physical 
  forces 
  will 
  often 
  give 
  better 
  

   results 
  in 
  pest 
  control 
  than 
  the 
  chemical 
  agents 
  now 
  employed. 
  Work- 
  

   ing 
  on 
  this 
  basis, 
  the 
  author 
  has 
  been 
  able 
  to 
  simplify 
  arsenical 
  treat- 
  

   ment 
  against 
  insect 
  pests 
  of 
  the 
  vine 
  and 
  also 
  to 
  test 
  the 
  value 
  of 
  

   hot 
  water 
  treatment 
  applied 
  during 
  the 
  period 
  of 
  growth. 
  In 
  using 
  

   arsenicals 
  against 
  Sparganothis, 
  the 
  larva 
  is 
  usually 
  assumed 
  to 
  emerge 
  

   from 
  the 
  bark 
  in 
  spring 
  and 
  to 
  enter 
  the 
  pupal 
  stage 
  in 
  June. 
  This 
  

   is 
  not 
  always 
  the 
  case, 
  and 
  the 
  vine-grower 
  who 
  has 
  applied 
  treatment 
  

   in 
  April 
  and 
  May 
  is 
  surprised 
  by 
  fresh 
  attacks 
  in 
  June 
  and 
  July. 
  

   The 
  various 
  stages 
  of 
  Clysia 
  and 
  Polychrosis 
  extend 
  over 
  still 
  

   longer 
  periods, 
  so 
  that 
  the 
  two 
  usual 
  sprayings 
  with 
  lead 
  arsenate 
  

  

  