﻿THE 
  ARMY 
  WORM: 
  NATURAL 
  ENEMIES. 
  127 
  

  

  tion 
  for 
  the 
  oft-quoted 
  story 
  of 
  the 
  finding 
  of 
  the 
  eggs 
  of 
  the 
  Army 
  

   Worm 
  covered 
  by 
  a 
  mass 
  of 
  loose 
  silk, 
  originally 
  j)ublished 
  by 
  Shurtleff, 
  

   in 
  the 
  Proceedings 
  of 
  the 
  Essex 
  Institute, 
  July 
  2, 
  1862. 
  One 
  of 
  our 
  

   correspondents, 
  Mr. 
  M. 
  B. 
  Kerr, 
  of 
  Aurora, 
  Ind,, 
  has 
  made 
  many 
  dis- 
  

   sections 
  of 
  Army 
  Worms 
  in 
  search 
  of 
  the 
  Military 
  Microgaster, 
  and 
  

   where 
  he 
  has 
  found 
  the 
  parasites 
  their 
  numbers 
  varied 
  from 
  sixty-two 
  

   to 
  ninety-six 
  to 
  an 
  individual 
  host. 
  From 
  the 
  cocoons 
  of 
  the 
  Military 
  

   Microgaster 
  there 
  often 
  issue 
  individuals 
  of 
  a 
  minute 
  secondary 
  para- 
  

   site 
  — 
  a 
  Chalcid, 
  called 
  by 
  Walsh 
  Glyphe 
  viridascens, 
  but 
  which 
  probably 
  

   belongs 
  to 
  the 
  genus 
  Tridymus. 
  

  

  In 
  our 
  Eighth 
  Missouri 
  Eeport, 
  p. 
  54, 
  we 
  mentioned 
  the 
  rearing 
  of 
  an- 
  

   other 
  Microgaster 
  from 
  the 
  Army 
  Worm, 
  which 
  differed 
  from 
  militaris 
  

   in 
  always 
  having 
  the 
  three 
  basal 
  joints 
  of 
  the 
  abdomen 
  rufous. 
  This 
  

   we 
  have 
  recently 
  shown" 
  to 
  be 
  a 
  variety 
  of 
  Apanteles 
  congregatus 
  Say 
  — 
  

   a 
  Microgaster 
  which 
  is 
  parasitic 
  upon 
  many 
  Sphinges, 
  Bombycids, 
  and 
  

   Noctuids, 
  and 
  perhaps 
  other 
  Lepidoptera. 
  This 
  species 
  is 
  also 
  parasitized 
  

   by 
  the 
  Glyphe 
  viridascens 
  mentioned 
  above. 
  This 
  latter, 
  by 
  the 
  way, 
  is 
  

   identical 
  with 
  the 
  Fteromalus 
  tahaeum 
  of 
  Fitch, 
  who 
  bred 
  it 
  from 
  Apan- 
  

   teles 
  congregatus 
  when 
  parasitic 
  upon 
  the 
  tobacco 
  worm 
  (Macrosila 
  quin- 
  

   quemaculata). 
  

  

  Another 
  Microgaster 
  which 
  is 
  probably 
  parasitic 
  upon 
  the 
  Army 
  

   Worm 
  is 
  the 
  Apanteles 
  Umenitidis 
  Eiley,^^ 
  form 
  flaviconchce, 
  as 
  its 
  bright 
  

   lemon 
  -yellow 
  cocoons 
  are 
  found 
  associated 
  with 
  those 
  of 
  the 
  Military 
  

   Microgaster 
  in 
  fields 
  infested 
  with 
  the 
  Army 
  Worm. 
  

  

  Finally, 
  we 
  have 
  bred 
  a 
  fourth 
  Microgaster 
  from 
  the 
  Army 
  Worm, 
  

   belonging 
  to 
  t 
  be 
  genus 
  Microplitis. 
  It 
  differs 
  from 
  the 
  other 
  species 
  

   mentioned 
  in 
  being 
  solitary, 
  only 
  a 
  single 
  larva 
  deriving 
  nourishment 
  

   from 
  the 
  partially 
  grown 
  Leucania 
  larva. 
  This 
  species 
  was 
  also 
  col- 
  

   lected 
  this 
  spring 
  at 
  Huntsville, 
  Ala., 
  by 
  Mr. 
  Howard. 
  

  

  A 
  small 
  Ichneumonid 
  parasite, 
  called 
  by 
  Walsh 
  '' 
  the 
  Glassy 
  Meso- 
  

   chorus 
  {Mesochorus 
  vitreus, 
  Plate 
  II, 
  Fig. 
  8), 
  was 
  supposed 
  b}^ 
  him 
  to 
  be 
  a 
  

   true 
  parasite 
  upon 
  the 
  Army 
  Worm, 
  but 
  we 
  have 
  recently 
  shown 
  '^^ 
  that 
  

   it 
  is 
  a 
  parasite 
  upon 
  the 
  Microgasters 
  above 
  mentioned, 
  and 
  it 
  is 
  prob- 
  

   able 
  that 
  it 
  cannot 
  be 
  called 
  a 
  true 
  Army 
  Worm 
  parasite. 
  

  

  In 
  the 
  Prairie 
  Farmer 
  (Vol. 
  YIII, 
  p. 
  258) 
  Walsh 
  described 
  another 
  

   parasite 
  under 
  the 
  name 
  of 
  IIocl<;eria 
  perpulchra^ 
  which 
  he 
  considered 
  as 
  

   parasitic 
  uj)on 
  one 
  of 
  the 
  Microgasters. 
  Only 
  18 
  per 
  cent, 
  of 
  the 
  true 
  

   Army 
  Worm 
  parasites, 
  according 
  to 
  Walsh, 
  perish 
  by 
  secondary 
  para- 
  

   sites. 
  

  

  The 
  Diminished 
  Pezomachus 
  (Pezomachus 
  minimus 
  Walsh, 
  Plate 
  II, 
  

   Fig. 
  9) 
  is 
  a 
  small, 
  wingless 
  parasite, 
  which, 
  like 
  the 
  Microgaster, 
  spins 
  

   cocoons 
  in 
  cottony 
  floss 
  on 
  the 
  back 
  of 
  the 
  worm, 
  but 
  places 
  them 
  

   close 
  together 
  in 
  symmetrical 
  order. 
  This 
  in 
  its 
  turn 
  is 
  preyed 
  upon 
  

   by 
  a 
  little 
  Chalcid 
  fly 
  [Smicra 
  albi/rons, 
  Walsh). 
  

  

  ^' 
  In 
  addition 
  to 
  these 
  small 
  parasites 
  there 
  are 
  a 
  few 
  larger 
  Ich- 
  

  

  41 
  Trans. 
  Acad. 
  Sci. 
  Saint 
  Louis, 
  Vol. 
  IV, 
  No. 
  2 
  (1881). 
  

   *2 
  See 
  Third 
  Missouri 
  Entomological 
  Eeport. 
  

   ** 
  Trans. 
  Acad. 
  Sci. 
  Saint 
  Louis, 
  ibid. 
  

  

  