﻿41 
  

  

  ON 
  THE 
  CHALCIDOID 
  PARASITES 
  OF 
  PSYLLIDS 
  (HEMIPTERA, 
  

  

  HOMOPTERA). 
  

  

  By 
  James 
  Waterston, 
  B.D., 
  D.Sc, 
  

  

  Assistant 
  in 
  the 
  Department 
  of 
  Entomology, 
  British 
  Museum. 
  

  

  (Published 
  by 
  permission 
  of 
  the 
  Trustees 
  of 
  the 
  British 
  Museum). 
  

  

  While 
  engaged 
  in 
  working 
  out 
  some 
  small 
  lots 
  of 
  Psyllid 
  parasites 
  from 
  various 
  

   parts 
  of 
  the 
  world, 
  I 
  have 
  found 
  it 
  necessary 
  to 
  examine, 
  as 
  far 
  as 
  possible, 
  the 
  

   records 
  of 
  Chalcids 
  which 
  up 
  to 
  the 
  present 
  have 
  been 
  bred 
  from 
  these 
  hosts. 
  The 
  

   literature 
  has 
  proved 
  to 
  be 
  more 
  extensive 
  than 
  had 
  been 
  anticipated, 
  and 
  it 
  has 
  

   therefore 
  seemed 
  well 
  to 
  bring 
  together 
  and 
  list 
  these 
  scattered 
  references 
  when 
  

   describing 
  the 
  forms 
  that 
  have 
  been 
  considered 
  as 
  new. 
  

  

  1. 
  Similarity 
  of 
  Coccid 
  and 
  Psyllid 
  Parasites. 
  — 
  In 
  the 
  following 
  summary 
  are 
  

   noted 
  18 
  species 
  belonging 
  to 
  the 
  families 
  Encyrtidae 
  (14) 
  and 
  Eulophidae 
  (4). 
  

   Of 
  the 
  eight 
  genera 
  containing 
  these 
  species 
  four 
  at 
  least 
  include 
  others 
  which 
  attack 
  

   Coccids. 
  In 
  one 
  instance 
  indeed 
  (T. 
  sicarius, 
  Silv.) 
  the 
  same 
  species 
  of 
  parasite 
  

   has 
  been 
  reared 
  from 
  hosts 
  of 
  both 
  families 
  (Coccids 
  and 
  Psyllids). 
  In 
  a 
  case 
  like 
  

   this 
  it 
  seems 
  probable 
  that 
  the 
  Tetrastichus 
  fails 
  to 
  discriminate 
  between 
  the 
  Coccid 
  

   scale 
  and 
  the 
  Psyllid 
  gall, 
  while 
  the 
  general 
  similarity 
  between 
  the 
  parasites 
  of 
  the 
  

   two 
  host 
  groups 
  is 
  doubtless 
  to 
  be 
  explained 
  on 
  phylogenetic 
  and 
  biological 
  grounds. 
  

  

  2. 
  Status. 
  — 
  The 
  Encyrtids 
  appear 
  to 
  be 
  mainly 
  primary 
  parasites, 
  but 
  the 
  relation- 
  

   ship 
  of 
  the 
  Tetrastichus 
  spp. 
  to 
  their 
  hosts 
  is 
  less 
  certain. 
  They 
  are 
  more 
  likely 
  

   to 
  be 
  secondary. 
  Andre 
  was 
  definitely 
  of 
  opinion 
  that 
  Agonioneurns 
  also 
  played 
  

   this 
  role. 
  

  

  3. 
  Host 
  stage 
  attacked, 
  etc. 
  — 
  The 
  majority 
  of 
  the 
  records, 
  when 
  precise 
  on 
  this 
  

   point, 
  agree 
  that 
  the 
  pupa 
  of 
  the 
  host 
  most 
  commonly 
  yields 
  parasites. 
  Andre, 
  

   however, 
  found 
  larvae 
  attacked 
  as 
  well. 
  Normally, 
  one 
  Encyrtid 
  hatches 
  from 
  a 
  

   pupa. 
  The 
  specimens 
  of 
  the 
  Chiloneurus 
  described 
  below 
  were 
  found 
  singly, 
  free 
  

   from 
  their 
  pupal 
  envelopes, 
  each 
  resting 
  in 
  a 
  depression 
  of 
  the 
  host 
  pupa, 
  their 
  only 
  

   covering 
  being 
  the 
  crust 
  of 
  the 
  gall. 
  When 
  this 
  had 
  been 
  removed, 
  the 
  parasite 
  

   floated 
  off 
  easily 
  in 
  potash. 
  The 
  Chiloneurus 
  larva 
  may 
  therefore 
  be 
  an 
  external 
  

   feeder, 
  at 
  least, 
  in 
  its 
  last 
  stage 
  (cf. 
  Andre's 
  remarks 
  on 
  Tetrastichus 
  obscuratus). 
  

  

  In 
  the 
  notices 
  of 
  species 
  already 
  described 
  it 
  has 
  been 
  thought 
  sufficient 
  to 
  quote 
  

   only 
  the 
  essential 
  facts 
  of 
  the 
  parasitism 
  in 
  each 
  case 
  and 
  the 
  location 
  of 
  the 
  type 
  

   where 
  known, 
  but 
  as 
  Bulletin 
  No. 
  5 
  of 
  the 
  U.S. 
  Dept. 
  of 
  Agriculture, 
  Div. 
  of 
  Ento- 
  

   mology, 
  1885, 
  is 
  now 
  scarce, 
  the 
  descriptions 
  of 
  Psyllid 
  parasites 
  which 
  it 
  contains 
  

   have 
  been 
  repeated 
  in 
  extenso, 
  as 
  well 
  as 
  the 
  notes 
  on 
  life-histories. 
  

  

  Family 
  Torymidae, 
  Walker. 
  

  

  The 
  following 
  record 
  of 
  a 
  " 
  Callimome 
  " 
  attacking 
  a 
  Psyllid 
  seems 
  to 
  me 
  to 
  be 
  open 
  

   to 
  doubt, 
  since 
  the 
  Torymids, 
  when 
  not 
  phytophagous, 
  appear 
  to 
  parasitise 
  mainly 
  

   Dipterous 
  or 
  Hymenopterous 
  hosts. 
  

  

  Genus 
  Callimome, 
  Spinola. 
  

  

  Callimome 
  pachypsyllae, 
  Vier. 
  

  

  C. 
  pachvpsvllae, 
  Viereck, 
  Guide 
  to 
  the 
  Insects 
  of 
  Connecticut, 
  iii, 
  Hymenoptera 
  

   (Bull. 
  No. 
  22, 
  State 
  Zoological 
  and 
  Natural 
  History 
  Survey 
  of 
  Connecticut), 
  

   Hartford, 
  1916, 
  p. 
  516. 
  

  

  