﻿616 
  

  

  late 
  years 
  in 
  the 
  above 
  district 
  and 
  great 
  damage 
  has 
  been 
  done 
  yearly. 
  

   In 
  1914, 
  fumigation 
  was 
  undertaken 
  in 
  two 
  large 
  orchards, 
  each 
  of 
  

   about 
  30 
  acres 
  and 
  each 
  surrounded 
  on 
  three 
  sides 
  by 
  small 
  plots 
  of 
  

   forest. 
  The 
  pests 
  were 
  on 
  the 
  wing 
  after 
  the 
  30th 
  May 
  and 
  fumi- 
  

   gation 
  was 
  carried 
  out 
  on 
  the 
  3rd 
  and 
  4th 
  June, 
  and 
  over 
  a 
  month 
  later 
  

   no 
  Psylla 
  mali 
  were 
  to 
  be 
  seen. 
  The 
  total 
  cost 
  of 
  the 
  remedy, 
  including 
  

   tobacco 
  dust, 
  straw 
  and 
  the 
  wages 
  of 
  six 
  workmen 
  and 
  one 
  foreman, 
  

   amounted 
  to 
  about 
  Is. 
  3d. 
  per 
  acre. 
  The 
  author 
  describes 
  the 
  manner 
  

   in 
  which 
  the 
  fumigation 
  was 
  carried 
  out, 
  which, 
  allowing 
  for 
  the 
  local 
  

   method 
  of 
  planting, 
  necessitated 
  some 
  variations 
  from 
  the 
  procedure 
  

   suggested 
  by 
  Dobrodeev 
  [see 
  this 
  Review, 
  Ser. 
  A, 
  ii, 
  p. 
  258]. 
  The 
  

   fumigation 
  should 
  be 
  done 
  in 
  the 
  evening, 
  immediately 
  after 
  the 
  pests 
  

   are 
  on 
  the 
  wing, 
  and 
  before 
  they 
  have 
  oviposited. 
  In 
  order 
  to 
  prevent 
  

   the 
  insects 
  escaping 
  from 
  the 
  orchards, 
  fumigation 
  should 
  begin 
  round 
  

   the 
  outside 
  of 
  the 
  orchard, 
  the 
  heaps 
  of 
  tobacco 
  dust 
  in 
  the 
  middle 
  

   being 
  fired 
  later. 
  

  

  Cameron 
  (A. 
  E.). 
  A 
  Contribution 
  to 
  a 
  Knowledge 
  of 
  the 
  Belladonna 
  

   Leaf-Miner, 
  Pegomyia 
  hyoscyami, 
  Panz., 
  its 
  Life-History 
  and 
  

   Biology. 
  — 
  Ann. 
  App. 
  Biol., 
  Cambridge 
  Univ. 
  Press, 
  i, 
  no. 
  1, 
  May 
  

   pp. 
  43-76, 
  1914, 
  2 
  pis., 
  4 
  figs. 
  

  

  There 
  is 
  great 
  confusion 
  in 
  the 
  literature 
  on 
  this 
  species, 
  owing 
  to 
  

   the 
  fact 
  that 
  it 
  has 
  a 
  considerable 
  number 
  of 
  food-plants 
  and 
  has 
  been 
  

   described 
  several 
  times 
  under 
  different 
  names. 
  There 
  appears 
  how- 
  

   ever 
  to 
  be 
  a 
  distinct 
  variety 
  which 
  particularly 
  attacks 
  beet 
  and 
  

   mangolds 
  and 
  periodically 
  causes 
  great 
  damage 
  to 
  these 
  crops 
  both 
  

   in 
  Europe 
  and 
  America. 
  The 
  author's 
  observations 
  are 
  based 
  upon 
  

   specimens 
  reared 
  upon 
  Deadly 
  Nightshade 
  (Atropa 
  belladonna). 
  This 
  

   insect 
  is 
  widely 
  spread 
  throughout 
  Europe 
  and 
  it 
  is 
  probably 
  to 
  be 
  

   found 
  wherever 
  beet, 
  spinach 
  and 
  mangolds 
  are 
  cultivated. 
  A 
  list 
  

   of 
  food-plants, 
  chiefly 
  among 
  the 
  Chenopodiacae 
  and 
  the 
  Solanaceae, 
  is 
  

   given 
  and 
  a 
  statement 
  by 
  Jablonowski 
  quoted, 
  that 
  if 
  the 
  natural 
  food- 
  

   plants 
  should 
  fail, 
  the 
  larvae 
  may 
  complete 
  their 
  development 
  on 
  a 
  

   diet 
  of 
  manure 
  or 
  decaying 
  vegetable 
  matter. 
  The 
  eggs, 
  larva, 
  

   puparium 
  and 
  adult 
  are 
  described. 
  Variation 
  in 
  the 
  size 
  and 
  structure 
  

   of 
  the 
  mature 
  larvae 
  appears 
  to 
  depend 
  to 
  a 
  considerable 
  extent 
  upon 
  

   the 
  food-plant. 
  

  

  The 
  eggs 
  are 
  laid 
  on 
  the 
  underside 
  of 
  the 
  leaf 
  in 
  parallel 
  rows 
  and 
  are 
  

   held 
  together 
  by 
  cement. 
  They 
  hatch 
  at 
  intervals 
  of 
  from 
  4 
  to 
  6 
  days, 
  

   generally 
  in 
  the 
  cool 
  of 
  the 
  evening. 
  The 
  larva 
  eats 
  its 
  way 
  into 
  the 
  

   parenchyma, 
  slowly 
  making 
  a 
  gallery 
  for 
  itself. 
  When 
  a 
  large 
  number 
  

   of 
  eggs 
  are 
  laid 
  on 
  one 
  leaf, 
  many 
  of 
  the 
  larvae 
  die 
  from 
  want 
  of 
  food, 
  

   and 
  those 
  which 
  hatch 
  first 
  appear 
  to 
  have 
  the 
  best 
  chance 
  of 
  survival. 
  

   The 
  larval 
  stages 
  are 
  apparently 
  three, 
  with 
  two 
  moults, 
  though 
  

   Carpenter 
  has 
  suggested 
  that 
  there 
  are 
  possibly 
  four 
  moults, 
  but 
  the 
  

   author 
  has 
  not 
  been 
  able 
  to 
  verify 
  this. 
  In 
  the 
  month 
  of 
  June 
  develop- 
  

   ment 
  was 
  completed 
  in 
  about 
  10 
  days, 
  while 
  in 
  September 
  as 
  many 
  as 
  

   12 
  days 
  were 
  required. 
  The 
  pupal 
  stage 
  may 
  be 
  two 
  or 
  three 
  weeks, 
  

   or 
  even 
  longer. 
  The 
  insects 
  hibernate 
  as 
  pupae, 
  and 
  larvae 
  collected 
  

   during 
  October 
  assumed 
  the 
  resting 
  condition 
  on 
  the 
  20th 
  of 
  that 
  

   month, 
  and 
  from 
  one 
  of 
  the 
  puparia, 
  which 
  were 
  kept 
  amongst 
  damp 
  

   sand 
  in 
  a 
  cool 
  house, 
  an 
  adult 
  emerged 
  on 
  May 
  24th 
  of 
  the 
  following 
  

  

  