﻿[16] 
  EEPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  sprouts 
  affected 
  with 
  the 
  eggs 
  of 
  the 
  insect 
  of 
  September 
  6 
  soon 
  recov- 
  

   ered 
  after 
  replanting 
  them. 
  From 
  6 
  a. 
  m. 
  till 
  9 
  p. 
  m. 
  the 
  temperature 
  

   was 
  marked 
  every 
  three 
  hours, 
  and 
  with 
  regard 
  to 
  the 
  then 
  also 
  nightly 
  

   mild 
  fall 
  weather 
  1^ 
  Eeaumur 
  less 
  than 
  the 
  average 
  temperature 
  at 
  9 
  

   p. 
  m. 
  and 
  6 
  a. 
  m. 
  was 
  accepted 
  for 
  the 
  omitted 
  nocturnal 
  observations. 
  

   The 
  hatching 
  of 
  the 
  maggots 
  took 
  place 
  on 
  September 
  14, 
  eight 
  days 
  

   after 
  oviposition. 
  From 
  the 
  stated 
  temperatures 
  and 
  the 
  sum 
  of 
  observa- 
  

   tions 
  (nights 
  taken 
  into 
  account), 
  the 
  average 
  temperature 
  of 
  those 
  

   eight 
  days 
  was 
  10.5o 
  Eeaumur 
  [55.5 
  F.]. 
  How 
  much 
  more 
  the 
  develop- 
  

   ment 
  of 
  the 
  maggot 
  from 
  the 
  egg 
  could 
  be 
  accelerated 
  by 
  increased 
  tem- 
  

   perature, 
  eggs 
  obtained 
  Octobers 
  yielded 
  a 
  striking 
  verification 
  : 
  the 
  

   maggot 
  so 
  rapidly 
  developed 
  in 
  a 
  warm 
  room 
  that 
  they 
  left 
  their 
  egg- 
  

   skins 
  as 
  soon 
  as 
  the 
  third 
  day. 
  

  

  The 
  freshly-hatched 
  maggots 
  very 
  slowly 
  wander 
  downward 
  in 
  the 
  

   longitudinal 
  valleys 
  between 
  the 
  leaf-nerves. 
  Their 
  motion 
  can 
  only 
  

   be 
  noticed 
  by 
  looking 
  at 
  them 
  for 
  a 
  long 
  time, 
  especially 
  by 
  means 
  of 
  

   a 
  magnifying-glass. 
  Several 
  hours 
  pass 
  before 
  the 
  maggot 
  reaches 
  the 
  

   base 
  of 
  the 
  leaf. 
  After 
  passing 
  the 
  latter 
  the 
  maggot 
  disappears, 
  and, 
  

   as 
  we 
  find 
  by 
  examining 
  the 
  sprout, 
  continues 
  to 
  wander 
  in 
  the 
  interior 
  

   down 
  to 
  near 
  the 
  root, 
  to 
  take 
  from 
  this 
  time 
  its 
  permanent 
  seat. 
  

  

  2. 
  The 
  maggot. 
  (Fig. 
  3 
  to 
  13.) 
  

  

  The 
  ground 
  color 
  of 
  the 
  larva 
  is 
  white, 
  but 
  when 
  the 
  maggot 
  has 
  just 
  

   left 
  the 
  egg-skin 
  it 
  shows 
  interiorly 
  a 
  flaky 
  appearance, 
  which 
  in 
  the 
  

   course 
  of 
  further 
  development 
  forms 
  the 
  so-called 
  adipose 
  body, 
  and 
  

   which 
  is 
  trajected 
  by 
  a 
  free 
  moving 
  red 
  liquid, 
  by 
  which 
  the 
  maggot 
  has 
  

   now 
  a 
  reddish-yellow 
  look. 
  In 
  the 
  movements 
  of 
  the 
  maggot 
  this 
  red 
  

   liquid 
  accumulates 
  in 
  certain 
  places 
  of 
  the 
  body 
  in 
  lacunes, 
  thereby 
  

   producing 
  the 
  blood-red 
  spots 
  which 
  appear 
  here 
  and 
  there 
  on 
  the 
  body. 
  

   The 
  maggot 
  is 
  now 
  elongate-oval, 
  head 
  end 
  pointed, 
  surface 
  bald 
  and 
  

   finely 
  wrinkled. 
  Its 
  length 
  an 
  hour 
  after 
  hatching 
  is 
  0.11°^™, 
  three 
  times 
  

   its 
  width, 
  but 
  on 
  the 
  third 
  day 
  already 
  0.32"^°^, 
  five 
  and 
  a 
  half 
  times 
  its 
  

   largest 
  diameter. 
  Of 
  the 
  subsequent 
  developmental 
  phases 
  scarcely 
  

   anything 
  more 
  is 
  to 
  be 
  said 
  than 
  that 
  the 
  maggot 
  gradually 
  acquires 
  a 
  

   more 
  elongate 
  form, 
  and 
  that 
  the 
  segmentation 
  of 
  the 
  body 
  becomes 
  

   more 
  distinct. 
  

  

  The 
  maggot 
  found 
  in 
  the 
  beginning 
  of 
  November, 
  in 
  winter 
  rye, 
  lay 
  

   head 
  downward, 
  just 
  above 
  the 
  base 
  of 
  the 
  roots. 
  The 
  maggot 
  had 
  a 
  

   length 
  of 
  about 
  3°^°^. 
  It 
  was 
  white, 
  laterally 
  transparent, 
  the 
  adipose 
  

   body 
  of 
  a 
  yellowish 
  -white 
  color. 
  Faint 
  lateral 
  emarginations 
  showed 
  

   fourteen 
  body 
  segments, 
  of 
  which 
  two 
  belong 
  to 
  the 
  head, 
  three 
  to 
  the 
  

   thorax, 
  and 
  nine 
  to 
  the 
  abdomen. 
  On 
  each 
  side 
  of 
  the 
  fleshy 
  mouth 
  pro- 
  

   truded 
  a 
  likewise 
  fleshy 
  sensory 
  point. 
  The 
  extremely 
  small 
  stigmata 
  

   could 
  be 
  seen 
  on 
  the 
  prothorax 
  and 
  the 
  first 
  eight 
  abdominal 
  segments. 
  

   The 
  motions 
  of 
  the 
  maggot 
  were 
  so 
  insiguificaht 
  that 
  they 
  could 
  be 
  re- 
  

   vealed 
  only 
  by 
  the 
  aid 
  of 
  a 
  microscope. 
  The 
  retracting 
  of 
  the 
  head 
  was 
  

   spy-glass-like 
  in 
  two 
  motions. 
  All 
  sprouts 
  on 
  which 
  the 
  maggot 
  was 
  

   found 
  were 
  either 
  decayed 
  or 
  visibly 
  sick 
  ; 
  their 
  yellow- 
  brown 
  color 
  much 
  

   contrasted 
  with 
  the 
  vivid 
  green 
  of 
  their 
  healthy 
  neighbors. 
  

  

  The 
  sowing 
  of 
  the 
  winter 
  rye 
  begins 
  here 
  and 
  in 
  the 
  immediate 
  neigh- 
  

   borhood 
  of 
  my 
  dwelling, 
  especially 
  owing 
  to 
  economical 
  reasons, 
  not 
  

   before 
  the 
  20th 
  of 
  September 
  j 
  that 
  of 
  wheat 
  still 
  later. 
  If 
  this 
  snffl- 
  

   ciently 
  demonstrates 
  why 
  the 
  gall-gnat 
  used 
  to 
  be 
  found 
  in 
  rye 
  only 
  

   and 
  not 
  also 
  in 
  wheat, 
  the 
  question, 
  however, 
  was 
  significant: 
  where 
  

  

  