﻿210 
  EEPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  clear, 
  transparent, 
  and 
  miicli 
  broader 
  wings, 
  and 
  pale-yellow 
  legs, 
  while 
  

   tbe 
  larvae 
  are 
  orange-colored, 
  and 
  live 
  crowded 
  around 
  the 
  wheat-grains 
  

   at 
  the 
  top 
  of 
  the 
  plant; 
  they 
  spin 
  a 
  silken, 
  round, 
  genuine 
  cocoon, 
  smaller 
  

   than 
  a 
  mustard 
  seed, 
  which 
  remains 
  in 
  the 
  ground 
  just 
  beneath 
  the 
  sur- 
  

   face. 
  So 
  it 
  will 
  be 
  seen 
  that 
  the 
  form 
  and 
  habits 
  of 
  the 
  two 
  insects 
  are 
  

   very 
  dissimilar, 
  and 
  that 
  they 
  need 
  not 
  be 
  confounded. 
  

  

  HABITS 
  OF 
  THE 
  HESSIAN 
  FLY. 
  

  

  Having 
  become 
  acquainted 
  with 
  the 
  appearance 
  of 
  this 
  two-winged 
  

   gall-fly 
  in 
  its 
  different 
  stages, 
  we 
  are 
  now 
  prepared 
  to 
  study 
  its 
  habits 
  ; 
  

   for 
  an 
  intimate 
  knowledge 
  of 
  how 
  it 
  comports 
  itself 
  as 
  an 
  egg, 
  larva, 
  

   "flaxseed," 
  and 
  perfect 
  winged 
  fly 
  is 
  absolutely 
  essential 
  to 
  the 
  faruier 
  

   who 
  would 
  endeavor 
  intelligently 
  to 
  combat 
  this 
  pest. 
  

  

  Number 
  of 
  broods. 
  — 
  The 
  Hessian 
  Fly 
  is 
  double 
  brooded, 
  the 
  ^'flax- 
  

   seeds 
  " 
  or 
  puparia 
  being 
  found 
  on 
  the 
  winter 
  wheat 
  from 
  late 
  in 
  the 
  au- 
  

   tumn, 
  through 
  the 
  winter, 
  until 
  the 
  early 
  part 
  or 
  middle 
  of 
  April. 
  The 
  

   ' 
  'flaxseeds 
  " 
  of 
  this 
  brood, 
  from 
  one 
  to 
  about 
  twenty 
  in 
  number, 
  are 
  situ- 
  

   ated 
  between 
  the 
  stalk 
  and 
  sheathing 
  base 
  of 
  the 
  leaf, 
  at 
  the 
  roots 
  of 
  

   the 
  young 
  grain, 
  slightly 
  beneath 
  the 
  surfiice 
  of 
  the 
  ground. 
  

  

  The 
  " 
  flaxseeds" 
  of 
  the 
  second 
  generation 
  affect 
  the 
  wheat 
  in 
  the 
  late 
  

   spring 
  and 
  summer 
  j 
  but 
  are 
  situated 
  higher 
  up, 
  an 
  inch 
  or 
  two 
  above 
  the 
  

   surface 
  of 
  the 
  ground, 
  at 
  the 
  lower 
  joints 
  of 
  the 
  straw. 
  

  

  In 
  the 
  ordinary 
  course 
  of 
  nature, 
  therefore 
  [says 
  Fitch], 
  our 
  crops 
  of 
  winter 
  wheat 
  

   are 
  liable 
  to 
  two 
  attacks 
  of 
  the 
  Hessian 
  Fly, 
  one 
  generation 
  reared 
  at 
  its 
  roots 
  produc- 
  

   ing 
  another, 
  which 
  occupies 
  the 
  lower 
  joints 
  of 
  the 
  stocks. 
  Thus 
  the 
  hirv?e. 
  and 
  pupse 
  

   are 
  present 
  in 
  it 
  almost 
  continually 
  from 
  the 
  time 
  the 
  tender 
  young 
  blades 
  appear 
  

   above 
  the 
  ground 
  in 
  autumn 
  till 
  the 
  grain 
  ripens 
  aud 
  is 
  harvested 
  the 
  next 
  summer. 
  

   Our 
  spring 
  wheat, 
  on 
  the 
  other 
  hand, 
  can 
  rear 
  but 
  one 
  brood 
  of 
  these 
  insects 
  ; 
  they 
  

   consequently 
  resort 
  to 
  it 
  but 
  little, 
  if 
  at 
  all. 
  Nor 
  can 
  the 
  Hessian 
  Fly 
  sustain 
  itself 
  

   except 
  in 
  districts 
  where 
  winter 
  wheat 
  is 
  cultivated 
  in 
  which 
  for 
  it 
  to 
  nestle 
  during 
  

   the 
  autumn 
  and 
  winter. 
  

  

  As 
  a 
  general 
  rule, 
  then, 
  there 
  are 
  two 
  broods 
  of 
  the 
  fly, 
  the 
  first 
  lay- 
  

   ing 
  their 
  eggs 
  late 
  in 
  April 
  and 
  in 
  May, 
  and 
  the 
  second 
  brood 
  of 
  flies 
  

   ovipositing"^ 
  in 
  August, 
  during 
  September, 
  and 
  perhaps 
  a 
  few 
  early 
  in 
  

   October. 
  Sometimes 
  the 
  flies 
  appear 
  earlier, 
  as 
  Professor 
  Cook, 
  who 
  ob- 
  

   served 
  the 
  insect 
  in 
  Michigan, 
  says 
  that 
  ''in 
  July 
  and 
  August 
  the 
  flies 
  

   again 
  issue 
  forth, 
  and 
  the 
  cycle 
  of 
  changes 
  for 
  the 
  year 
  is 
  complete. 
  

   Thus 
  we 
  see 
  that 
  the 
  flies 
  are 
  ready 
  for 
  work 
  in 
  the 
  fall, 
  much 
  before 
  

   the 
  wheat 
  is 
  ready 
  for 
  them, 
  and 
  may 
  attack 
  a 
  volunteer 
  crop 
  long 
  be- 
  

   fore 
  the 
  usual 
  crop 
  is 
  above 
  ground 
  or 
  even 
  sown." 
  

  

  A 
  third 
  broodmay 
  sometimes 
  appear, 
  as 
  shown 
  by 
  Mr. 
  B. 
  Hulick, 
  of 
  Mich- 
  

   igan. 
  According 
  to 
  Professor 
  Cook, 
  Mr. 
  Hulick 
  found 
  the 
  empty 
  "flax- 
  

   seeds 
  " 
  on 
  volunteer 
  wheat 
  in 
  September. 
  On 
  Professor 
  Cook's 
  expressing 
  

  

  1" 
  Mr. 
  F. 
  S. 
  Sleeper 
  writes 
  us 
  that 
  ho 
  has 
  on 
  one 
  occasion 
  seen 
  the 
  Hessian 
  Flies 
  laying 
  their 
  eggs 
  as 
  

   late 
  as 
  October 
  26. 
  In 
  February, 
  1878, 
  during 
  verj 
  mild 
  weather, 
  he 
  observed 
  them 
  laying 
  their 
  eggs 
  

   in 
  February. 
  S&e 
  his 
  statements, 
  farther 
  on. 
  

  

  