﻿DESCRIPTION 
  OF 
  THE 
  HESSIAN 
  FLY. 
  207 
  

  

  mimity 
  estimated 
  at 
  several 
  hundred 
  thousand 
  dollars, 
  aud 
  called 
  attention 
  also 
  to 
  

   the 
  relative 
  abundance 
  of 
  parasites 
  among 
  the 
  insects 
  now 
  maturing. 
  — 
  American 
  Nat- 
  

   uralist, 
  December, 
  1882. 
  

  

  These 
  facts 
  indicate 
  that 
  the 
  losses 
  from 
  the 
  Hessian 
  Fly 
  are 
  greatest 
  

   in 
  the 
  grain 
  raising 
  areas 
  of 
  the 
  Central 
  States, 
  and 
  adjoining 
  regions 
  

   of 
  Canada, 
  and 
  that 
  the 
  ^ew 
  England 
  States 
  have 
  been 
  comparatively 
  

   free 
  from 
  their 
  attacks, 
  though 
  this 
  is 
  perhaps 
  mainly 
  due 
  to 
  the 
  fact 
  

   that 
  so 
  little 
  wheat 
  is 
  cultivated 
  there. 
  No 
  statistics 
  as 
  to 
  the 
  losses 
  

   have 
  been 
  collected 
  until 
  of 
  late, 
  either 
  by 
  the 
  State 
  or 
  national 
  govern- 
  

   ments, 
  but 
  they 
  have 
  been 
  sufficient 
  to 
  occasion 
  much 
  consternation 
  and 
  

   alarm 
  at 
  certain 
  years. 
  By 
  reference 
  to 
  the 
  chapter 
  on 
  the 
  supposed 
  

   periodicity 
  in 
  its 
  attacks 
  or 
  years 
  of 
  maximum 
  abundance, 
  the 
  reader 
  

   may 
  learn 
  approximately 
  by 
  the 
  history 
  of 
  the 
  past 
  how 
  often 
  its 
  more 
  

   serious 
  attacks 
  may 
  be 
  probably 
  renewed. 
  

  

  DESCRIPTION 
  OF 
  THE 
  HESSIAN 
  FLY. 
  

  

  This 
  insect 
  belongs 
  to 
  the 
  Diptera 
  or 
  two-winged 
  insects, 
  of 
  which 
  

   the 
  common 
  house-fly 
  is 
  the 
  best-known 
  type. 
  It 
  belongs 
  to 
  the 
  family 
  

   Ceddomyidce, 
  a 
  large 
  groui3 
  of 
  minute 
  flies, 
  resembling 
  the 
  crane 
  flies 
  or 
  

   daddy-long-legs 
  {Tipulidce), 
  but 
  of 
  diminutive 
  form. 
  They 
  are 
  nearly 
  all 
  

   gall-flies, 
  the 
  females 
  laying 
  their 
  eggs 
  by 
  means 
  of 
  the 
  soft 
  extensible 
  

   >end 
  of 
  the 
  body 
  which 
  slides 
  back 
  and 
  forth 
  like 
  the 
  joints 
  of 
  a 
  tele- 
  

   scope. 
  The 
  irritation 
  caused 
  by 
  the 
  egg 
  results 
  in 
  the 
  swelling 
  of 
  the 
  

   stems 
  of 
  plants, 
  or 
  the 
  formation 
  of 
  tumors 
  or 
  galls 
  on 
  the 
  leaves 
  and 
  

   buds. 
  The 
  Hessian 
  Fly, 
  as 
  we 
  shall 
  see 
  farther 
  on, 
  does 
  not 
  produce 
  

   true 
  galls 
  in 
  this 
  way, 
  but 
  the 
  presence 
  of 
  the 
  insect 
  in 
  the 
  flaxseed 
  

   state, 
  between 
  the 
  leaf 
  and 
  the 
  stalk, 
  causes 
  the 
  stem 
  to 
  swell, 
  and 
  the 
  

   leaves 
  to 
  wither 
  and 
  die. 
  The 
  scientific 
  name 
  is 
  Cecidomyia 
  destructor 
  

   of 
  Say. 
  

  

  The 
  female 
  (Plate 
  lY, 
  /; 
  Y, 
  A). 
  — 
  The 
  body 
  is 
  rather 
  slender, 
  uniformly 
  

   dark 
  brown, 
  the 
  head 
  is 
  round, 
  but 
  somewhat 
  flattened, 
  the 
  eyes 
  are 
  black, 
  

   the 
  wings 
  uniformly 
  dull 
  smoky 
  brown, 
  while 
  the 
  legs 
  are 
  paler 
  brown 
  than 
  

   the 
  rest 
  of 
  the 
  upper 
  side 
  of 
  the 
  body. 
  The 
  body, 
  wings, 
  and 
  legs 
  are 
  

   provided 
  with 
  fine 
  hair-like 
  scales 
  (Plate 
  Y, 
  J., 
  c), 
  those 
  on 
  the 
  wings 
  being 
  

   in 
  many 
  cases 
  quite 
  broad 
  and 
  ribbed, 
  somewhat 
  like 
  the 
  scales 
  on 
  the 
  

   wings 
  of 
  a 
  butterfly 
  or 
  moth. 
  The 
  pale 
  brown 
  antennae 
  are 
  about 
  half 
  

   as 
  long 
  as 
  the 
  body, 
  the 
  joints 
  are 
  very 
  distinct, 
  like 
  a 
  string 
  of 
  beads, 
  

   each 
  one 
  being 
  oval-cylindrical. 
  There 
  are 
  seventeen 
  joints, 
  the 
  two 
  

   basal 
  ones 
  being 
  large, 
  nearly 
  globular, 
  flattened 
  lengthwise, 
  and 
  nearly 
  

   half 
  as 
  long 
  as 
  thick, 
  and 
  each 
  of 
  nearly 
  equal 
  sizej 
  joints 
  3-5 
  are 
  longer 
  

   than 
  the 
  remaining 
  ones, 
  and 
  are 
  slightly 
  contracted 
  in 
  the 
  middle; 
  

   the 
  remaining 
  6-17 
  gradually 
  decrease 
  in 
  length, 
  each 
  joint 
  being 
  pro- 
  

   vided 
  with 
  about 
  ten 
  hairs, 
  arranged 
  in 
  a 
  rude 
  whorl; 
  the 
  terminal 
  joint 
  

   (Plate 
  Y, 
  A, 
  a') 
  is 
  long 
  and 
  conical. 
  The 
  legs 
  are 
  of 
  the 
  same 
  color 
  as 
  

   the 
  under 
  side 
  of 
  the 
  body, 
  being 
  a 
  little 
  paler 
  than 
  the 
  back. 
  The 
  ab- 
  

   domen 
  is 
  rather 
  full, 
  with 
  nine 
  well-marked 
  rings 
  or 
  segments, 
  the 
  

  

  