﻿31 
  

  

  When 
  this 
  weed 
  first 
  comes 
  up 
  in 
  the 
  early 
  spring 
  there 
  is 
  scarcely 
  

   any 
  vegetation, 
  so 
  that 
  it 
  offers 
  an 
  agreeable 
  host 
  to 
  the 
  bean 
  thrips, 
  

   especially 
  as 
  the 
  foliage 
  is 
  very 
  tender 
  and 
  juic}^ 
  at 
  that 
  time. 
  The 
  

   thrips 
  attack 
  the 
  first 
  young 
  leaves, 
  and 
  the 
  larvae, 
  upon 
  hatching 
  

   from 
  eggs 
  deposited 
  at 
  that 
  time, 
  join 
  the 
  feeding 
  adults. 
  As 
  soon 
  

   as 
  these 
  become 
  abundant, 
  the 
  leaves 
  lose 
  all 
  or 
  nearly 
  all 
  of 
  the 
  green 
  

   leaf 
  -content 
  and 
  turn 
  white, 
  after 
  which 
  they 
  dry 
  up 
  and 
  hang 
  dead 
  

   from 
  the 
  stalk. 
  The 
  infestation 
  continues 
  to 
  spread 
  to 
  the 
  younger 
  

   leaves 
  until 
  the 
  entire 
  plant 
  is 
  killed. 
  

  

  The 
  sow 
  thistle 
  {Sonchus 
  oleraceus) 
  has 
  the 
  same 
  general 
  distri- 
  

   bution 
  and 
  is 
  also 
  a 
  favorite 
  food 
  plant. 
  

  

  Wild 
  heliotrope 
  (Heliotropium< 
  curassavicum) 
  is 
  another 
  favorite 
  

   food 
  plant 
  late 
  in 
  the 
  year. 
  This 
  plant 
  does 
  not 
  start 
  in 
  the 
  spring 
  

   until 
  quite 
  late, 
  and 
  when 
  it 
  does 
  appear 
  above 
  the 
  ground 
  generally 
  

   escapes 
  destruction 
  by 
  cultivation. 
  Thus 
  it 
  occurs 
  commonly 
  in 
  the 
  

   beet 
  and 
  bean 
  fields 
  and 
  in 
  orchards, 
  and 
  in 
  the 
  fall 
  is 
  one 
  of 
  the 
  

   chief 
  food 
  plants. 
  

  

  The 
  bean 
  thrips 
  has 
  also 
  been 
  found 
  feeding 
  and 
  reproducing 
  in 
  

   numbers 
  on 
  Euryptera 
  lucida 
  and 
  on 
  one 
  of 
  the 
  cucurbitacese, 
  prob- 
  

   ably 
  an 
  Echinocystis, 
  in 
  a 
  canyon 
  north 
  of 
  Los 
  Angeles. 
  In 
  the 
  same 
  

   locality 
  it 
  was 
  later 
  taken 
  feeding 
  and 
  reproducing 
  on 
  Gnaphalium 
  

   calif 
  ornicum, 
  Mirabilis 
  calif 
  ornica, 
  E 
  unarms 
  orevipes, 
  Chenopodium 
  

   murale, 
  Heliantlius 
  annuus, 
  Atriplex 
  sp., 
  wild 
  turnip, 
  Erigeron 
  cana- 
  

   densis, 
  and 
  wild 
  pea 
  {Lotus 
  am,ericanus) 
  . 
  It 
  was 
  also 
  taken 
  in 
  the 
  

   valleys 
  feeding 
  and 
  reproducing 
  on 
  the 
  Chinese 
  cigarette 
  flower 
  (Nic- 
  

   oiiana 
  glauca), 
  Bidens 
  pilosa, 
  Verhascum 
  virgatum, 
  Polygonum 
  avi~ 
  

   culare, 
  and 
  Crepsis 
  (?) 
  sp. 
  The 
  adults 
  were 
  also 
  taken 
  in 
  the 
  fall 
  

   feeding 
  on 
  the 
  foliage 
  of 
  a 
  porch 
  vine, 
  Tacsonia 
  mellissimus, 
  and 
  on 
  

   the 
  cultivated 
  nasturtium 
  {Tropceolum 
  major). 
  Mr. 
  A. 
  C. 
  Morgan 
  

   found 
  it 
  on 
  the 
  underside 
  of 
  the 
  leaves 
  of 
  the 
  tulip 
  poplar 
  at 
  Clarks- 
  

   ville, 
  Tenn. 
  

  

  This 
  thrips 
  has 
  also 
  been 
  recorded 
  as 
  feeding 
  on 
  Lotus 
  glaber, 
  

   apple, 
  peach, 
  orange, 
  wild 
  vetch, 
  burr 
  clover, 
  and 
  radish. 
  

  

  After 
  perusal 
  of 
  the 
  above 
  list 
  of 
  food 
  plants 
  it 
  is 
  easy 
  to 
  see 
  how 
  

   this 
  insect 
  can 
  obtain 
  a 
  foothold 
  in 
  a 
  cultivated 
  crop 
  in 
  the 
  late 
  

   summer, 
  especially 
  as 
  many 
  of 
  the 
  wild 
  plants 
  die 
  from 
  maturity 
  or 
  

   lack 
  of 
  moisture, 
  thus 
  forcing 
  the 
  insect 
  to 
  migrate. 
  

  

  SEASONAL 
  HISTORY 
  AT 
  COMPTON, 
  CAL. 
  

  

  The 
  life 
  cycle 
  of 
  the 
  bean 
  thrips 
  was 
  observed 
  at 
  Compton 
  for 
  vary- 
  

   ing 
  parts 
  of 
  the 
  year, 
  and 
  because 
  of 
  the 
  cooler 
  and 
  more 
  even 
  tem- 
  

   perature 
  prevailing 
  there 
  is 
  quite 
  extended 
  and 
  more 
  nearly 
  equal 
  

   for 
  the 
  entire 
  period 
  of 
  reproductive 
  activity. 
  

  

  THE 
  EGG. 
  

  

  The 
  length 
  of 
  time 
  required 
  for 
  the 
  egg 
  to 
  hatch 
  in 
  (lie 
  months 
  of 
  

   March, 
  April, 
  and 
  May 
  was 
  not 
  exactly 
  determined. 
  However, 
  fresh 
  

  

  