﻿371 
  

  

  May 
  till 
  about 
  the 
  middle 
  of 
  July. 
  The 
  eggs 
  are 
  laid 
  in 
  the 
  earth 
  near 
  

   the 
  roots 
  of 
  the 
  plants 
  and 
  hatch 
  in 
  14 
  to 
  16 
  days, 
  the 
  larvae 
  as 
  they 
  

   emerge 
  penetrating 
  into 
  the 
  knobs 
  on 
  the 
  roots. 
  In 
  the 
  absence 
  of 
  

   sufficient 
  knobs, 
  as 
  in 
  the 
  case 
  of 
  peas, 
  the 
  larvae 
  perish 
  in 
  great' 
  

   numbers. 
  Having 
  eaten 
  the 
  contents 
  of 
  the 
  knob, 
  the 
  larvae 
  issue 
  

   and 
  live 
  in 
  the 
  soil, 
  passing 
  from 
  one 
  knob 
  to 
  another 
  ; 
  the 
  adult 
  . 
  

   larvae 
  feed 
  on 
  the 
  roots. 
  The 
  development 
  of 
  the 
  larva 
  from 
  egg 
  till 
  . 
  

   pupation 
  lasts 
  32-34 
  days. 
  The 
  larvae 
  gradually 
  pass 
  deeper 
  into 
  

   the 
  soil, 
  the 
  maximum 
  depth 
  being 
  about 
  5J 
  inches 
  ; 
  pupation 
  taking 
  

   place 
  at 
  a 
  depth 
  of 
  about 
  IJ 
  inches. 
  The 
  first 
  pupae 
  were 
  found 
  

   underneath 
  clover 
  and 
  vetches 
  after 
  10th 
  July. 
  The 
  pupal 
  stage 
  lasts 
  

   10-12 
  days 
  ; 
  thus 
  the 
  whole 
  cycle 
  of 
  development 
  of 
  S. 
  lineatus 
  

   requires 
  about 
  60 
  days. 
  Observations 
  showed 
  that 
  the 
  beetles 
  do 
  not 
  

   pair 
  during 
  the 
  same 
  summer 
  in 
  which 
  they 
  emerge, 
  and 
  it 
  is 
  therefore 
  

   assumed 
  that 
  there 
  is 
  only 
  one 
  generation 
  annually. 
  The 
  whole 
  life 
  

   of 
  the 
  imago 
  lasts 
  about 
  14 
  months. 
  A 
  table 
  is 
  given 
  showing 
  the 
  

   stages 
  of 
  the 
  insects 
  existing 
  in 
  each 
  of 
  the 
  12 
  months 
  of 
  the 
  year. 
  

   The 
  author 
  records 
  his 
  experiments 
  on 
  spraying 
  with 
  Paris 
  green 
  in 
  

   the 
  proportion 
  of 
  1 
  oz. 
  of 
  green 
  and 
  about 
  3 
  oz. 
  of 
  freshly 
  slaked 
  lime 
  

   in 
  9 
  gallons 
  of 
  water. 
  About 
  50 
  per 
  cent, 
  of 
  the 
  beetles 
  perished, 
  but 
  

   the 
  insecticide 
  produced 
  bums 
  on 
  the 
  leaves 
  ; 
  it 
  is 
  intended 
  to 
  repeat 
  

   this 
  experiment 
  next 
  year 
  on 
  a 
  larger 
  scale. 
  Great 
  importance 
  is 
  also 
  

   attached 
  to 
  the 
  reploughing 
  of 
  the 
  attacked 
  fields 
  at 
  the 
  time 
  when 
  the 
  

   insects 
  are 
  in 
  the 
  pupal 
  stage. 
  

  

  Oscinella 
  frit 
  winters 
  in 
  the 
  larval 
  stage 
  on 
  winter-sown 
  wheat 
  and 
  

   rye, 
  and 
  on 
  wild 
  grasses. 
  When 
  dug 
  out 
  of 
  the 
  snow, 
  the 
  larvae 
  were 
  

   active 
  and 
  kept 
  on 
  feeding 
  ; 
  cold 
  has 
  no 
  particular 
  effect 
  on 
  them. 
  

   The 
  wintering 
  larva 
  develops 
  in 
  8 
  months 
  and 
  pupates 
  after 
  the 
  first 
  

   half 
  of 
  May, 
  the 
  imago 
  appearing 
  last 
  year 
  on 
  about 
  28th 
  May. 
  The 
  

   spring 
  generation 
  of 
  the 
  flies 
  oviposited 
  on 
  summer-sown 
  crops 
  (oats, 
  

   wheat, 
  barley) 
  and 
  on 
  wild 
  grasses 
  (Phleum 
  pratense, 
  Alopecurus 
  

   pratensis, 
  Lolium 
  perenne, 
  Triticum 
  cristatum, 
  Festuca 
  pratensis, 
  Avena 
  

   Jlavescens 
  and 
  Poa 
  pratensis). 
  At 
  the 
  time 
  of 
  oviposition 
  the 
  crops 
  

   had 
  already 
  tillered 
  and 
  the 
  central 
  leaf 
  had 
  a 
  length 
  of 
  5-6 
  inches 
  ; 
  

   the 
  eggs 
  were 
  laid 
  on 
  both 
  sides 
  of 
  the 
  leaves 
  ; 
  on 
  some 
  plants 
  they 
  

   were 
  laid 
  on 
  the 
  stalk 
  near 
  the 
  tillering 
  knot. 
  Usually 
  one 
  Qgg 
  is 
  

   deposited 
  on 
  one 
  leaf, 
  although 
  plants 
  were 
  found 
  bearing 
  as 
  many 
  as 
  3 
  

   eggs 
  at 
  one 
  spot. 
  The 
  spring 
  egg 
  develops 
  in 
  4 
  days 
  ; 
  the 
  pupation 
  

   of 
  the 
  larvae 
  hatched 
  from 
  these 
  eggs 
  started 
  on 
  the 
  14th 
  June, 
  the 
  

   imago 
  of 
  the 
  summer 
  generation 
  appearing 
  after 
  the 
  27th 
  June 
  ; 
  these 
  

   flies 
  oviposited 
  on 
  ears 
  of 
  summer-sown 
  crops 
  and 
  on 
  badly 
  grown 
  

   crops. 
  The 
  autumn 
  generation 
  started 
  flying 
  on 
  17th 
  August 
  and 
  

   oviposited 
  on 
  winter-sown 
  crops 
  (rye, 
  wheat) 
  their 
  eggs 
  developing 
  

   in 
  7 
  days. 
  The 
  whole 
  cycle 
  of 
  development 
  of 
  the 
  flies 
  of 
  the 
  summer 
  

   and 
  autumn 
  generation 
  required 
  30-32 
  days, 
  while 
  the 
  winter 
  

   generation 
  requires 
  about 
  9 
  months. 
  From 
  the 
  cocoons 
  of 
  the 
  flies 
  

   the 
  parasites 
  Rhoptromeris 
  wildhalmi, 
  Kurd., 
  and 
  Trichomalus 
  cristatus, 
  

   Forst., 
  were 
  reared, 
  the 
  infection 
  of 
  the 
  spring 
  generation 
  was 
  30 
  per 
  

   cent., 
  that 
  of 
  the 
  summer 
  one 
  20 
  per 
  cent. 
  Owing 
  to 
  the 
  small 
  num- 
  

   bers 
  of 
  flies 
  of 
  the 
  spring 
  generation 
  and 
  to 
  the 
  fact 
  that 
  at 
  the 
  time 
  

   of 
  their 
  appearance 
  the 
  plants 
  were 
  strong, 
  the 
  flies 
  did 
  not 
  touch 
  the 
  

   principal 
  stems, 
  but 
  oviposited 
  on 
  the 
  side-shoots 
  ; 
  the 
  late 
  summer 
  

   crops 
  were 
  more 
  affected. 
  Figures 
  are 
  given 
  showing 
  that 
  the 
  flies 
  

  

  C37 
  c2 
  

  

  