﻿742 
  KEPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  of 
  these, 
  on 
  the 
  under 
  side 
  of 
  the 
  body, 
  are 
  two 
  additional 
  teeth, 
  like 
  minute 
  feet, 
  

   by 
  the 
  aid 
  of 
  which 
  the 
  maggot 
  shoves 
  itself 
  forward 
  when 
  crawling. 
  (Fitch.) 
  Speci- 
  

   mens 
  from 
  Essex 
  County, 
  Massachusetts, 
  are 
  long, 
  conical, 
  the 
  end 
  of 
  the 
  body 
  squarely 
  

   docked, 
  with 
  barrel-shaped 
  spiracles 
  projecting 
  from 
  the 
  end 
  of 
  the 
  body. 
  On 
  the 
  

   under 
  side 
  of 
  the 
  segments 
  are 
  raised 
  folds, 
  one 
  to 
  each 
  segment, 
  and 
  of 
  service 
  in 
  loco- 
  

   motion. 
  The 
  spiracles 
  and 
  termination 
  of 
  the 
  tracheae 
  or 
  air-tubes 
  are 
  very 
  distinct 
  

   on 
  the 
  prothorax, 
  while 
  there 
  are 
  no 
  traces 
  of 
  antenpse. 
  The 
  fly 
  is 
  like 
  the 
  common 
  

   house-fly, 
  but 
  smaller 
  and 
  slenderer. 
  The 
  two 
  sexes 
  are 
  readily 
  distinguished 
  from 
  

   each 
  other 
  by 
  the 
  eyes, 
  which 
  in 
  the 
  males 
  are 
  close 
  together 
  and 
  so 
  large 
  as 
  to 
  occupy 
  

   almost 
  the 
  whole 
  surface 
  of 
  the 
  head, 
  while 
  in 
  the 
  female 
  they 
  are 
  widely 
  separated 
  

   from 
  each 
  other. 
  These 
  flies 
  are 
  of 
  an 
  ash-gray 
  color, 
  with 
  the 
  head 
  silvery, 
  and 
  a 
  

   rusty-black 
  stripe 
  between 
  the 
  eyes, 
  forked 
  at 
  its 
  hind 
  end. 
  The 
  species 
  is 
  particu- 
  

   larly 
  distinguished 
  by 
  having 
  a 
  row 
  of 
  black 
  spots 
  along 
  the 
  middle 
  of 
  the 
  abdomen 
  

   or 
  hind 
  body, 
  which 
  sometimes 
  run 
  into 
  each 
  other, 
  then 
  forming 
  a 
  continuous 
  black 
  

   stripe. 
  This 
  row 
  of 
  spots 
  is 
  quite 
  distinct 
  in 
  the 
  male, 
  but 
  in 
  the 
  female 
  it 
  is 
  very 
  

   faint 
  or 
  is 
  often 
  wholly 
  imperceptible. 
  This 
  fly 
  measures 
  0.22 
  to 
  0.25 
  inch 
  in 
  length, 
  

   the 
  females 
  being 
  usually 
  rather 
  larger 
  than 
  the 
  males. 
  (Fitch.) 
  

  

  Remedies. 
  — 
  As 
  a 
  preventive 
  measure 
  worth 
  trial 
  the 
  seed 
  should 
  be 
  

   sown 
  two 
  inches 
  deeper 
  than 
  usual, 
  so 
  that 
  the 
  fly 
  cannot 
  so 
  readily 
  get 
  

   to 
  it 
  to 
  lay 
  its 
  eggs. 
  Sow 
  also 
  on 
  ground 
  on 
  which 
  straw 
  has 
  been 
  pre- 
  

   viously 
  burned. 
  Kotation 
  of 
  crops 
  is 
  also 
  a 
  most 
  important 
  preventive 
  

   measure. 
  When 
  the 
  roots 
  are 
  infested 
  pour 
  boiling 
  water 
  along 
  the 
  

   drills 
  near 
  the 
  roots, 
  or 
  even 
  on 
  the 
  plants, 
  going 
  over 
  the 
  bed 
  four 
  

   times 
  during 
  one 
  season. 
  The 
  diseased 
  onions 
  should 
  be 
  pulled 
  up 
  and 
  

   burned. 
  Fitch 
  recommends 
  cultivating 
  the 
  onions 
  in 
  hills, 
  scattered 
  

   among 
  the 
  other 
  vegetables 
  in 
  the 
  garden. 
  " 
  With 
  only 
  three 
  or 
  four 
  

   seedlings 
  in 
  a 
  hill 
  it 
  is 
  evident 
  that 
  the 
  young 
  worms 
  could 
  nowhere 
  

   find 
  a 
  suflBcient 
  amount 
  of 
  food 
  to 
  nourish 
  them 
  to 
  maturity. 
  Having 
  

   consumed 
  all 
  the 
  young 
  plants 
  in 
  one 
  hill, 
  they 
  will 
  be 
  unable 
  to 
  work 
  

   their 
  way 
  through 
  the 
  ground 
  to 
  come 
  at 
  another 
  hill 
  except 
  it 
  be 
  by 
  

   the 
  merest 
  chance, 
  and 
  will 
  thus 
  perish." 
  

  

  The 
  Black 
  Onion-Fly, 
  Ortalisflexa 
  Wiedermann. 
  (Plate 
  LXVII, 
  Fig. 
  2.) 
  —Infesting 
  

   the 
  bulb 
  in 
  the 
  Western 
  States 
  ; 
  a 
  more 
  slender, 
  less 
  conical 
  maggot 
  than 
  the 
  Euro- 
  

   pean 
  onion-maggot, 
  with 
  the 
  head 
  blunter 
  ; 
  killing 
  the 
  tops 
  and 
  causing 
  the 
  onions 
  to 
  

   decay; 
  changing 
  to 
  a 
  black 
  fly, 
  with 
  three 
  oblique 
  white 
  stripes 
  on 
  each 
  wing. 
  

  

  This 
  native 
  onion-fly 
  was 
  first 
  found 
  to 
  be 
  destructive 
  to 
  onions 
  in 
  

   Illinois 
  by 
  Dr. 
  Henry 
  Shimer, 
  who 
  writes 
  in 
  the 
  Practical 
  Entomologist 
  

   (i, 
  4) 
  as 
  follows 
  regarding 
  it 
  : 
  " 
  In 
  the 
  latter 
  part 
  of 
  June 
  I 
  first 
  observed 
  

   the 
  larva 
  or 
  maggot 
  among 
  the 
  onions 
  here 
  ; 
  the 
  top 
  dead, 
  tuber 
  rot- 
  

   ten, 
  and 
  the 
  maggots 
  in 
  the 
  decayed 
  substance. 
  From 
  them 
  I 
  bred 
  the 
  

   fly. 
  They 
  passed 
  about 
  two 
  weeks 
  in 
  the 
  pupa 
  state. 
  At 
  that 
  time 
  I 
  

   first 
  observed 
  the 
  flies 
  in 
  the 
  garden, 
  and 
  now 
  few 
  are 
  to 
  be 
  found. 
  

   Their 
  favorite 
  roosting 
  place 
  is 
  a 
  row 
  of 
  asparagus 
  running 
  along 
  the 
  

   onion-ground, 
  where 
  they 
  are 
  easily 
  captured 
  and 
  destroyed, 
  from 
  day- 
  

   light 
  to 
  sunrise, 
  while 
  it 
  is 
  cool 
  and 
  wet. 
  During 
  the 
  day 
  they 
  are 
  scat- 
  

   tered 
  over 
  the 
  ground 
  and 
  on 
  the 
  leaves 
  and 
  stalks 
  of 
  the 
  onions, 
  and 
  not 
  

   easily 
  captured. 
  Their 
  wings 
  point 
  obliquely 
  backward, 
  outward, 
  and 
  

   upward, 
  with 
  an 
  irregular 
  jerkiug, 
  fan-like 
  movement; 
  flight 
  not 
  very 
  

   rapid- 
  or 
  prolonged. 
  They 
  are 
  not 
  very 
  numerous, 
  probably 
  not 
  over 
  200 
  

   or 
  300. 
  All 
  that 
  I 
  observed 
  originated 
  in 
  one 
  part 
  of 
  the 
  bed, 
  where 
  ■ 
  

   they 
  were 
  doubtless 
  deposited 
  by 
  one 
  parent 
  fly. 
  Two 
  broods 
  appear 
  

   in 
  a 
  season." 
  

  

  The 
  Onion-Thrips, 
  Limothrijys 
  triiiei 
  Fitch. 
  (Plate 
  LXVII, 
  Figs. 
  3-5.)— 
  Attacking 
  

   the 
  leaves, 
  causing 
  them 
  to 
  turn 
  yellow 
  and 
  wilt 
  and 
  die; 
  minute, 
  yellow, 
  slender 
  

   insects, 
  living 
  on 
  the 
  leaves 
  in 
  all 
  stages 
  of 
  growth. 
  

  

  The 
  following 
  account 
  is 
  taken 
  from 
  my 
  Second 
  Annual 
  Keport 
  on 
  the 
  

   Injurious 
  and 
  Beneficial 
  Insects 
  of 
  Massachusetts: 
  

  

  "About 
  the 
  middle 
  of 
  August 
  my 
  attention 
  was 
  called 
  by 
  Mr. 
  B. 
  P. 
  

  

  