﻿Order 
  THYSANOPTERA. 
  

  

  The 
  insects 
  of 
  this 
  order 
  are 
  commonly 
  known 
  as 
  "Thrips" 
  and 
  often 
  

   cause 
  severe 
  injurs^ 
  to 
  growing 
  plants. 
  They 
  are 
  very 
  small, 
  very 
  slender, 
  

   somewhat 
  fusiform, 
  with 
  very 
  delicate 
  narrow 
  fringed 
  wings, 
  which 
  are 
  

   laid 
  iiat 
  upon 
  the 
  back 
  when 
  at 
  rest 
  and 
  are 
  not 
  even 
  visible 
  to 
  the 
  ordi- 
  

   nary 
  observer 
  without 
  a 
  lens. 
  

  

  The 
  mouth 
  parts 
  are 
  made 
  up 
  of 
  a 
  number 
  of 
  slender 
  lancets, 
  only 
  the 
  

   points 
  of 
  which 
  protrude 
  beyond 
  the 
  mouth 
  opening. 
  With 
  these 
  they 
  

   scrape 
  the 
  surface 
  of 
  the 
  leaf 
  or 
  plant 
  and 
  exhaust 
  the 
  cell 
  beneath, 
  

   leaving 
  a 
  yellow 
  or 
  whitish 
  spot. 
  Onion 
  leaves 
  sometimes 
  turn 
  almost 
  

   white 
  under 
  a 
  severe 
  attack, 
  and 
  "silver-tip" 
  in 
  grasses 
  is 
  often 
  due 
  to 
  these 
  

   insects. 
  Cabbage 
  leaves 
  are 
  sometimes 
  completely 
  devitalized, 
  and 
  grow- 
  

   ing 
  tips 
  of 
  young 
  trees 
  may 
  be 
  crippled. 
  Not 
  all 
  species 
  are 
  harmful, 
  

   however, 
  some 
  of 
  them 
  occurring 
  under 
  such 
  conditions 
  as 
  to 
  make 
  it 
  

   almost 
  certain 
  that 
  they 
  are 
  predatory. 
  Yet 
  as 
  a 
  whole 
  this 
  little 
  order 
  

   must 
  be 
  considered 
  as 
  injurious. 
  

  

  As 
  to 
  remedial 
  measures 
  it 
  

   is 
  difficult 
  to 
  make 
  recom- 
  

   mendations. 
  Ordinarily 
  the 
  

   species 
  flourish 
  only 
  in 
  dry 
  

   weather, 
  and 
  their 
  injuries 
  in- 
  

   crease 
  and 
  manifest 
  them- 
  

   selves 
  in 
  a 
  dry 
  season, 
  or 
  

   after 
  a 
  protracted 
  drought. 
  

   A 
  cold 
  rain 
  may 
  check 
  them, 
  

   when 
  they 
  threaten 
  most, 
  and 
  

   a 
  spray 
  of 
  cold 
  water, 
  thor- 
  

   oughly 
  applied, 
  is 
  often 
  suffi- 
  

   cient 
  for 
  their 
  control. 
  Tobacco 
  decoction 
  and 
  soap 
  suds 
  are 
  good 
  addi- 
  

   tions, 
  and 
  may 
  generally 
  be 
  relied 
  upon 
  to 
  kill 
  off 
  the 
  species 
  in 
  the 
  green- 
  

   house 
  and 
  garden. 
  

  

  Very 
  little 
  has 
  been 
  added 
  to 
  our 
  knowledge 
  of 
  the 
  New 
  Jersey 
  species 
  

   since 
  the 
  previous 
  edition, 
  and 
  the 
  number 
  of 
  forms 
  has 
  not 
  been 
  in- 
  

   creased 
  by 
  collections. 
  Mr. 
  Pergande 
  is, 
  therefore, 
  still 
  to 
  be 
  credited 
  

   with 
  the 
  notes. 
  

  

  antenna 
  of 
  

  

  Fig. 
  28. 
  — 
  Thrips 
  tahaci: 
  a, 
  adul 
  

  

  same; 
  c, 
  young 
  larva; 
  d, 
  full-grown 
  larva; 
  

   enlarged. 
  

  

  Family 
  THRIPID^. 
  

  

  COLEOTHRIPS 
  Halid. 
  

  

  C. 
  trifasciata 
  Fitch. 
  Infests 
  grain 
  and 
  grasses. 
  

  

  CHIROTHRIPS 
  Halid. 
  

   C. 
  antennatus 
  Osb. 
  Infests 
  grasses. 
  

  

  (83) 
  

  

  