﻿18 
  THE 
  BEAN 
  THKIPS. 
  

  

  The 
  male. 
  1 
  when 
  inclined 
  to 
  copulate, 
  picks 
  out 
  a 
  female, 
  and 
  if 
  

   she 
  is 
  moving 
  over 
  the 
  leaf 
  runs 
  after 
  her 
  and 
  jumps 
  or 
  alights 
  on 
  her 
  

   back. 
  In 
  some 
  cases 
  he 
  then 
  spreads 
  the 
  wings 
  and 
  moves 
  them 
  up 
  

   and 
  down, 
  at 
  the 
  same 
  time 
  moving 
  the 
  tip 
  of 
  the 
  abdomen 
  in 
  the 
  

   same 
  manner. 
  In 
  other 
  cases 
  the 
  male, 
  after 
  leaping 
  onto 
  the 
  back 
  

   of 
  the 
  female, 
  remains 
  motionless 
  for 
  some 
  time 
  in 
  that 
  position. 
  It 
  

   then 
  exserts 
  the 
  copulatory 
  organs 
  from 
  the 
  tip 
  of 
  the 
  abdomen 
  and 
  

   shifts 
  around 
  toward 
  the 
  side 
  of 
  the 
  female, 
  at 
  the 
  same 
  time 
  bend- 
  

   ing 
  the 
  abdomen 
  under 
  to 
  the 
  ventral 
  side 
  of 
  that 
  of 
  the 
  female. 
  The 
  

   copulating 
  organs 
  are 
  then 
  moved 
  back 
  and 
  forth 
  until 
  they 
  en- 
  

   counter 
  those 
  of 
  the 
  female. 
  In 
  some 
  cases 
  observed, 
  when 
  the 
  male 
  

   did 
  not 
  succeed 
  in 
  connection, 
  it 
  would 
  withdraw 
  to 
  its 
  former 
  posi- 
  

   tion 
  on 
  the 
  female 
  and 
  after 
  remaining 
  quiet 
  for 
  a 
  short 
  time 
  would 
  

   move 
  over 
  and 
  attempt 
  the 
  act 
  on 
  the 
  opposite 
  side. 
  As 
  soon 
  as 
  con- 
  

   nection 
  is 
  made 
  the 
  male 
  remains 
  motionless 
  for 
  a 
  short 
  time, 
  during 
  

   which 
  period 
  the 
  female, 
  in 
  many 
  cases, 
  crawls 
  slowly 
  around 
  on 
  

   the 
  leaf. 
  After 
  a 
  few 
  minutes 
  the 
  male 
  relinquishes 
  his 
  hold 
  with 
  

   the 
  copulating 
  organs 
  and 
  moves 
  squarely 
  back 
  onto 
  the 
  dorsum 
  of 
  

   the 
  female. 
  Soon 
  after 
  the 
  male 
  crawls 
  off 
  and 
  away 
  from 
  the 
  female. 
  

   This 
  entire 
  operation 
  was 
  observed 
  in 
  three 
  cases 
  to 
  occupy 
  3, 
  5, 
  and 
  

   10 
  minutes. 
  Several 
  cases 
  were 
  observed 
  where 
  two 
  males 
  attempted 
  

   copulation 
  with 
  the 
  same 
  female, 
  but, 
  after 
  a 
  vain 
  attempt, 
  one 
  

   generally 
  left 
  her. 
  

  

  METHOD 
  AND 
  TIME 
  OF 
  OVIPOSITION. 
  

  

  Exactly 
  how 
  much 
  time 
  elapses 
  between 
  copulation 
  and 
  oviposition 
  

   was 
  not 
  observed, 
  but 
  probably 
  not 
  more 
  than 
  a 
  day, 
  so 
  that 
  the 
  

   female 
  will 
  begin 
  oviposition 
  within 
  three 
  days 
  from 
  the 
  time 
  she 
  

   emerges 
  from 
  the 
  pupa. 
  In 
  one 
  case 
  adults 
  emerged 
  on 
  July 
  19, 
  

   1911, 
  and 
  eggs 
  were 
  laid 
  four 
  days 
  later. 
  

  

  Oviposition 
  usually 
  takes 
  place 
  during 
  the 
  night, 
  but 
  has 
  been 
  

   observed 
  at 
  2, 
  3, 
  and 
  4.30 
  in 
  the 
  afternoon. 
  A 
  female 
  engaged 
  in 
  

   oviposition 
  was 
  observed 
  to 
  crawl 
  over 
  the 
  leaf 
  of 
  the 
  food 
  plant 
  

   for 
  a 
  short 
  distance 
  and 
  then 
  to 
  stop 
  and 
  scrape 
  a 
  hole 
  in 
  the 
  leaf 
  

   with 
  her 
  mouth 
  cone. 
  This 
  was 
  accomplished 
  by 
  a 
  slight 
  forward 
  

   and 
  backward 
  motion 
  like 
  that 
  of 
  a 
  chisel. 
  In 
  a 
  short 
  time 
  the 
  

   female 
  ceased 
  this 
  action 
  and 
  moving 
  forward 
  until 
  she 
  could 
  place 
  

   the 
  tip 
  of 
  the 
  abdomen 
  where 
  the 
  tissue 
  had 
  been 
  ruptured, 
  arched 
  

   the 
  abdomen 
  in 
  the 
  middle, 
  and 
  brought 
  the 
  tip 
  to 
  the 
  opening 
  in 
  

  

  1 
  Pietro 
  Buffa 
  (Atti 
  Soc. 
  Toscano 
  Soc. 
  Nat. 
  Mem., 
  vol. 
  23, 
  p. 
  48, 
  1907) 
  figures 
  JEolothrips 
  

   fasciatus, 
  female 
  and 
  male 
  in 
  copulation, 
  in 
  a 
  position 
  identical 
  with 
  that 
  observed 
  by 
  

   the 
  writer 
  in 
  Heliothrips 
  fasciatus 
  on 
  many 
  different 
  occasions. 
  

  

  A. 
  F. 
  Shull 
  (A 
  Biological 
  Survey 
  of 
  the 
  Sand 
  Dune 
  Region 
  of 
  Saginaw 
  Bay, 
  Mich., 
  

   pp. 
  190-192), 
  describing 
  copulation 
  in 
  the 
  suborder 
  Terebrantia, 
  expresses 
  doubt 
  as 
  to 
  

   the 
  position 
  of 
  the 
  male 
  on 
  the 
  back 
  of 
  the 
  female 
  during 
  copulation. 
  As 
  his 
  observa- 
  

   tions 
  on 
  Euthrips 
  tritici 
  were 
  made 
  under 
  unfavorable 
  conditions 
  his 
  conclusions 
  were 
  

   probably 
  erroneous. 
  

  

  