﻿PACKARD.l 
  THE 
  ONION-THEIPS. 
  743 
  

  

  Ware, 
  of 
  Swainpscott, 
  to 
  his 
  serious 
  loss 
  of 
  onions 
  from 
  the 
  attacks 
  of 
  

   a 
  minute 
  insect. 
  The 
  leaves 
  were 
  observed 
  to 
  suddenly 
  turn 
  yellow 
  and 
  

   wilt, 
  and 
  the 
  plant 
  died. 
  In 
  this 
  way 
  large 
  patches 
  became 
  infested 
  and 
  

   turned 
  yellow, 
  until 
  in 
  two 
  or 
  three 
  days 
  these 
  prolific 
  insects 
  spread 
  

   over 
  the 
  whole 
  field. 
  They 
  seemed 
  to 
  increase 
  most 
  rapidly 
  during 
  the 
  

   unusual 
  dry, 
  hot 
  weather 
  that 
  we 
  experienced 
  about 
  the 
  middle 
  of 
  last 
  

   August. 
  On 
  the 
  11th 
  of 
  August 
  a 
  whole 
  acre 
  was 
  thus 
  cut 
  off. 
  Mr. 
  

   Ware 
  informed 
  me 
  that 
  the 
  onion-plants 
  have 
  been 
  more 
  or 
  less 
  infested 
  

   in 
  this 
  way 
  for 
  some 
  fifteen 
  years, 
  but 
  the 
  damage 
  done 
  this 
  year 
  was 
  

   greater 
  than 
  ever 
  before. 
  This 
  evil 
  seems 
  wide-spread 
  in 
  Essex 
  County, 
  

   as 
  not 
  in 
  Swampscott 
  alone, 
  but 
  in 
  Lynn, 
  Salem, 
  and 
  parts 
  of 
  Danvers, 
  

   the 
  onion-crop 
  has 
  been 
  similarly 
  infested. 
  About 
  $100,000 
  worth 
  of 
  

   onions 
  are 
  raised 
  in 
  Essex 
  County 
  alone, 
  and 
  Mr. 
  Ware 
  judged 
  that 
  at 
  

   least 
  a 
  tenth 
  part 
  was 
  destroyed 
  by 
  this 
  new 
  pest 
  ; 
  so 
  that 
  in 
  one 
  county 
  

   alone 
  and 
  by 
  one 
  kind 
  of 
  injurious 
  insect 
  we 
  have 
  in 
  one 
  season 
  lost 
  

   $10,000. 
  The 
  onion-crop 
  is 
  next 
  to 
  the 
  hay-crop 
  in 
  value, 
  as 
  it 
  is 
  sold 
  

   for 
  cash. 
  

  

  " 
  On 
  examining 
  the 
  specimens 
  brought 
  into 
  the 
  Museum 
  of 
  the 
  Peabody 
  

   Academy 
  of 
  Science 
  the 
  leaves 
  were 
  found 
  to 
  be 
  covered 
  with 
  hundreds 
  

   of 
  a 
  minute 
  thrips, 
  which, 
  by 
  gnawing 
  the 
  surface 
  of 
  the 
  leaves, 
  had 
  

   caused 
  them 
  to 
  turn 
  white 
  in 
  spots, 
  and 
  subsequently 
  yellow 
  ; 
  where 
  

   they 
  were 
  most 
  numerous 
  the 
  outer 
  skin 
  of 
  the 
  fleshy 
  leaves 
  was 
  

   entirely 
  eateu 
  off, 
  and 
  though 
  it 
  was 
  difficult 
  to 
  imagine 
  that 
  so 
  minute 
  

   insects 
  could 
  have 
  caused 
  the 
  death 
  of 
  so 
  stout 
  and 
  thick-leaved 
  a 
  plant, 
  

   yet 
  here 
  were 
  hundreds 
  of 
  the 
  culprits 
  in 
  all 
  stages 
  of 
  growth 
  plying 
  

   their 
  jaws 
  before 
  our 
  eyes 
  in 
  proof. 
  

  

  "This 
  insect, 
  which 
  occurred 
  in 
  both 
  sexes 
  and 
  in 
  all 
  stages 
  of 
  growth 
  

   from 
  larvse 
  of 
  minute 
  size, 
  proved 
  to 
  be 
  the 
  wheat-thrips 
  of 
  Fitch 
  {Lim- 
  

   othrips 
  tritid), 
  who 
  gives 
  an 
  account 
  of 
  its 
  appearance 
  and 
  habits 
  in 
  his 
  

   'Second 
  Report 
  on 
  the 
  Noxious, 
  etc.. 
  Insects 
  of 
  New 
  York,' 
  p. 
  301. 
  His 
  

   attention 
  was 
  first 
  called 
  to 
  this 
  insect 
  by 
  a 
  correspondent 
  in 
  Wisconsin, 
  

   who 
  found 
  them 
  in 
  great 
  numbers 
  in 
  blossoms 
  of 
  various 
  plants. 
  He 
  

   wrote 
  Dr. 
  Fitch 
  that 
  they 
  first 
  'made 
  their 
  appearance 
  about 
  the 
  middle 
  

   of 
  June, 
  or 
  at 
  least 
  they 
  were 
  then 
  first 
  noticed, 
  so 
  far 
  as 
  I 
  have 
  heard. 
  

   For 
  about 
  two 
  weeks 
  they 
  were 
  found 
  in 
  the 
  blossoms 
  of 
  wheat 
  and 
  of 
  

   clover, 
  causing 
  numbers 
  of 
  the 
  blossoms 
  to 
  wither, 
  and 
  in 
  some 
  cases 
  

   the 
  kernel 
  was 
  also 
  attacked.' 
  Dr. 
  Fitch 
  himself 
  never 
  seems 
  to 
  have 
  

   noticed 
  this 
  insect 
  in 
  New 
  York, 
  nor 
  that 
  it 
  has 
  ever 
  been 
  found 
  in 
  the 
  

   onion, 
  but 
  thinks 
  it 
  is 
  the 
  species 
  to 
  which 
  Dr. 
  Harris 
  refers 
  in 
  his 
  

   treatise. 
  In 
  that 
  work 
  the 
  author 
  speaks 
  of 
  a 
  ' 
  pernicious 
  insect 
  in 
  the 
  

   ears 
  of 
  growing 
  wheat,' 
  which 
  ' 
  seems 
  to 
  agree 
  with 
  the 
  accounts 
  of 
  the 
  

   Thrijps 
  cerealium 
  which 
  sometimes 
  infests 
  wheat 
  in 
  Europe 
  to 
  a 
  great 
  

   extent.' 
  From 
  his 
  brief 
  description 
  it 
  is 
  probably 
  the 
  insect 
  now 
  under 
  

   consideration 
  to 
  which 
  Dr. 
  Harris 
  refers. 
  

  

  "The 
  various 
  kinds 
  of 
  thrips 
  are 
  minute, 
  narrow-bodied 
  insects 
  seldom 
  

   exceeding 
  a 
  line 
  in 
  length, 
  and 
  remotely 
  allied 
  to 
  the 
  bed-bug 
  and 
  squash- 
  

   bug 
  in 
  structure, 
  but 
  differing 
  from 
  them 
  in 
  having 
  free 
  jaws 
  adapted 
  to 
  

   biting, 
  while 
  those 
  of 
  the 
  bed 
  or 
  squash 
  bug 
  form 
  with 
  the 
  other 
  mouth- 
  

   organs 
  a 
  sharp, 
  hard 
  beak, 
  with 
  which 
  they 
  puncture 
  leaves, 
  or 
  the 
  flesh 
  

   of 
  their 
  victims, 
  when 
  carnivorous 
  in 
  their 
  tastes. 
  These 
  thrips 
  are 
  

   further 
  distinguished 
  by 
  their 
  wings 
  being 
  very 
  long 
  and 
  narrow, 
  and 
  

   beautifully 
  fringed 
  ; 
  and 
  when 
  folded 
  over 
  their 
  back 
  they 
  do 
  not 
  conceal 
  

   the 
  body 
  beneath, 
  as 
  is 
  usually 
  the 
  case. 
  Moreover, 
  they 
  are 
  exceed- 
  

   ingly 
  active 
  in 
  their 
  habits, 
  running 
  or 
  leaping 
  like 
  fleas. 
  

  

  ^'DesGri^ytion. 
  — 
  The 
  females 
  alone 
  are 
  winged, 
  the 
  males 
  being 
  wingless 
  and 
  closely 
  re- 
  

   eembling 
  the 
  larvse. 
  The 
  body 
  of 
  the 
  female 
  is 
  smooth 
  and 
  shining, 
  uniformly 
  green- 
  

  

  