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  Deltocephalus 
  inimicus 
  Say. 
  

  

  {/ass 
  us 
  inimicus 
  Say.) 
  

  

  This 
  is 
  one 
  of 
  the 
  four 
  or 
  five 
  species 
  of 
  leaf-hoppers 
  most 
  abundarit 
  

   in 
  beet 
  fields, 
  and 
  most 
  likely 
  to 
  cause 
  trouble 
  there. 
  It 
  is 
  widely 
  dis- 
  

   tributed 
  over 
  this 
  country 
  and 
  

   into 
  Canada, 
  and 
  is 
  one 
  of 
  the 
  

   most 
  persistent 
  and 
  destructive 
  

   leaf-hoppers 
  of 
  pastures 
  and 
  

   meadows. 
  It 
  was 
  especially 
  com- 
  

   mon 
  last 
  season 
  on 
  beets 
  during 
  

   the 
  early 
  part 
  of 
  October, 
  and 
  

   has 
  also 
  been 
  reported 
  from 
  cel- 
  

   ery, 
  corn, 
  and 
  buckwheat; 
  but 
  its 
  

   preferred 
  food 
  is 
  evidently 
  grass. 
  

   Its 
  life 
  history 
  has 
  been 
  very 
  

   thoroughly 
  studied 
  by 
  Osborn. 
  

   The 
  eggs, 
  he 
  says, 
  have 
  been 
  

   found 
  inserted 
  beneath 
  the 
  epi- 
  

   dermis 
  of 
  blue-grass 
  blades, 
  form- 
  

   ing 
  minute 
  blister-like 
  swellings- 
  

   near 
  the 
  tips 
  of 
  the 
  leaves, 
  the 
  

   end 
  of 
  the 
  leaf 
  beyond 
  this 
  in- 
  

   variably 
  turning 
  yellow 
  and 
  

   dying. 
  Webster 
  secured 
  the 
  eggs- 
  

   in 
  wheat 
  leaves. 
  The 
  nymphs 
  

   are 
  mostly 
  light 
  yellowish, 
  with 
  a 
  

   broad 
  black 
  margin 
  each 
  side, 
  

   the 
  head 
  obtusely 
  rounded 
  in 
  

   front. 
  At 
  intervals 
  of 
  seven 
  to 
  eight 
  days 
  they 
  fix 
  themselves 
  upon 
  the 
  

   grass 
  blades, 
  head 
  upward, 
  and 
  shed 
  their 
  skins, 
  which 
  split 
  along 
  the 
  

   back, 
  permitting 
  the 
  insects 
  to 
  struggle 
  out. 
  The 
  cast 
  skins 
  remain 
  for 
  

   some 
  time 
  clinging 
  to 
  the 
  grass 
  blades. 
  Three 
  molts 
  occur 
  (Osborn,. 
  

   Webster) 
  from 
  the 
  egg 
  to 
  the 
  adult. 
  

  

  Like 
  most 
  jassids 
  this 
  species 
  winters 
  in 
  the 
  egg 
  stage, 
  hatching 
  in 
  

   great 
  numbers 
  in 
  grass-lands 
  early 
  in 
  May. 
  The 
  young 
  mature 
  during 
  

   the 
  first 
  half 
  of 
  June, 
  the 
  adults 
  thus 
  produced 
  mostly 
  disappearing 
  by 
  the 
  

   middle 
  of 
  July. 
  These 
  lay 
  eggs 
  which 
  hatch 
  after 
  ten 
  or 
  fifteen 
  days, 
  

   the 
  nymphs 
  becoming 
  adult 
  in 
  about 
  a 
  month, 
  beginning, 
  that 
  is, 
  about 
  

   the 
  middle 
  of 
  August. 
  Eggs 
  are 
  then 
  laid 
  for 
  the 
  next 
  season's 
  brood, 
  

   and 
  the 
  adults 
  laying 
  them 
  perish 
  by 
  the 
  time 
  winter 
  sets 
  in. 
  There 
  are 
  

   thus 
  two 
  broods 
  yearly, 
  the 
  larvse 
  being 
  most 
  numerous 
  in 
  late 
  May 
  and 
  

   in 
  August, 
  and 
  the 
  adults 
  in 
  June 
  and 
  in 
  the 
  fall. 
  Large 
  numbers 
  of 
  the 
  

   latter 
  appeared 
  here 
  at 
  electric 
  lights 
  June 
  3-18. 
  

  

  Fig. 
  12. 
  Deltocephalus 
  inimicus: 
  <j, 
  adult; 
  ^.face 
  

   c, 
  head 
  and 
  pronotum 
  from 
  above; 
  d, 
  female, 
  e, 
  male, 
  

   genitalia;/", 
  elytron; 
  i', 
  nymph. 
  (Osborn 
  and 
  Ball.) 
  

  

  