﻿10 
  THE 
  BEAN 
  THEIPS. 
  

  

  THE 
  ADULT 
  MALE. 
  

  

  The 
  male 
  resembles 
  to 
  a 
  great 
  extent 
  the 
  female, 
  as 
  the 
  color 
  

   and 
  the 
  markings 
  are 
  the 
  same, 
  but 
  it 
  is 
  noticeably 
  smaller 
  in 
  size 
  

   and 
  apparently 
  more 
  active. 
  When 
  viewed 
  under 
  the 
  microscope 
  

   the 
  sexual 
  organs 
  are 
  seen 
  to 
  be 
  distinctly 
  different, 
  and 
  in 
  light- 
  

   colored 
  or 
  cleared 
  specimens 
  the 
  testes 
  may 
  be 
  seen 
  as 
  two 
  orange-red 
  

   bodies 
  in 
  the 
  abdomen, 
  and 
  on 
  the 
  middle 
  of 
  each 
  of 
  segments 
  2 
  to 
  6 
  

   on 
  the 
  ventral 
  side 
  are 
  yellowish 
  oval 
  spots. 
  The 
  total 
  length 
  of 
  

   the 
  male 
  is 
  0.7097 
  mm. 
  to 
  0.8002 
  mm. 
  ; 
  the 
  average, 
  0.7474 
  mm. 
  The 
  

   greatest 
  width 
  across 
  the 
  mesothorax 
  is 
  0.1963 
  mm. 
  to 
  0.2114 
  mm. 
  ; 
  

   the 
  average, 
  0.1978 
  mm. 
  

  

  RECENTLY 
  EMERGED 
  ADULTS. 
  

  

  Both 
  sexes, 
  when 
  just 
  emerged, 
  have 
  the 
  head 
  and 
  thorax 
  a 
  light 
  

   yellowish 
  orange, 
  with 
  the 
  eyes 
  and 
  ocelli 
  bright 
  red. 
  The 
  antennae 
  

   are 
  white 
  and 
  ringed 
  with 
  brown, 
  while 
  the 
  wings 
  are 
  dusky, 
  crossed 
  

  

  by 
  bands 
  of 
  a 
  darker 
  color. 
  The 
  legs 
  are 
  

   white, 
  with 
  ends 
  of 
  each 
  segment 
  more 
  or 
  less 
  

   black. 
  Gradually 
  the 
  color 
  darkens, 
  and 
  in 
  

   a 
  day 
  they 
  all 
  have 
  the 
  fully 
  matured 
  colors, 
  

   as 
  described 
  above. 
  

  

  THE 
  EGG. 
  

  

  fig. 
  3.— 
  The 
  bean 
  thrips 
  : 
  The 
  egg 
  (fig. 
  3) 
  is 
  bean 
  shaped, 
  0.21 
  to 
  

   KMginnn 
  eatly 
  enlarged 
  ' 
  0.255 
  mm. 
  in 
  length 
  and 
  0.105 
  to 
  0.12 
  mm. 
  in 
  

   width, 
  and 
  is 
  very 
  delicate 
  and 
  thin 
  shelled. 
  

   It 
  is 
  translucent 
  white, 
  Avith 
  a 
  smooth 
  shining 
  surface. 
  The 
  eggs 
  are 
  

   laid 
  in 
  the 
  tissue 
  of 
  the 
  leaf 
  or 
  in 
  the 
  veins, 
  or 
  even 
  in 
  the 
  stems, 
  and 
  

   in 
  case 
  of 
  beans 
  may 
  be 
  laid 
  in 
  the 
  pods 
  themselves. 
  As 
  the 
  embryo 
  

   within 
  develops, 
  the 
  egg 
  becomes 
  swollen, 
  and 
  the 
  little 
  pocket 
  in 
  

   which 
  it 
  is 
  inserted 
  becomes 
  raised 
  above 
  the 
  leaf 
  surface. 
  The 
  eggs 
  

   may 
  be 
  seen 
  in 
  the 
  leaf 
  tissue 
  if 
  examined 
  with 
  a 
  hand 
  lens 
  before 
  

   the 
  light. 
  Each 
  little 
  egg 
  pocket 
  stands 
  out, 
  because 
  of 
  its 
  lighter 
  

   color, 
  and 
  within 
  the 
  crude 
  outline 
  of 
  the 
  egg 
  may 
  be 
  seen. 
  

  

  The 
  younger 
  stages 
  of 
  this 
  insect 
  differ 
  distinctly 
  from 
  those 
  of 
  

   Heliothrips 
  hcemorrhoidalis 
  x 
  in 
  the 
  dashes 
  of 
  crimson 
  so 
  generally 
  

   present 
  on 
  the 
  sides. 
  . 
  

  

  THE 
  EIRST-STAGE 
  LARVA. 
  2 
  

  

  (Fig. 
  4.) 
  

  

  Length, 
  0.42 
  mm. 
  ; 
  width 
  of 
  mesothorax, 
  0.135 
  mm. 
  General 
  shape 
  fusiform, 
  

   similar 
  to 
  Heliothrips 
  hcemorrhoidalis; 
  head, 
  antennae, 
  and 
  legs 
  large 
  in 
  propor- 
  

  

  1 
  For 
  description 
  of 
  Heliothrips 
  hcemorrhoidalis, 
  see 
  " 
  The 
  Greenhouse 
  Thrips," 
  Bui. 
  64, 
  

   Part 
  VI, 
  Bur. 
  Ent., 
  U. 
  S. 
  Dept. 
  Agi\, 
  pp. 
  46-48, 
  1909. 
  

  

  - 
  I 
  Ascription 
  made 
  while 
  larva 
  was 
  very 
  young 
  and 
  hefore 
  feeding 
  commenced. 
  

  

  