﻿NATURAL 
  ENEMIES 
  OF 
  THE 
  LOCUST. 
  265 
  

  

  "au 
  niilieu 
  des 
  de*blais, 
  ou 
  gisaient 
  par-ci 
  par-la 
  des 
  coques 
  de 
  Colletes'' 
  (Ann. 
  Soc. 
  

   Ent. 
  Franco, 
  3d 
  ser., 
  torn, 
  vi, 
  p. 
  505, 
  pi. 
  13, 
  Fig. 
  Ill, 
  and 
  details). 
  The 
  larva 
  is 
  elon- 
  

   gated, 
  apod 
  and 
  fleshy, 
  and 
  of 
  a 
  white 
  color. 
  The 
  preceding 
  observations 
  clearly 
  prove 
  

   that 
  the 
  larva' 
  of 
  the 
  Bombylii 
  are 
  parasites 
  in 
  the 
  nests 
  of 
  other 
  insects, 
  in 
  the 
  manner 
  

   of 
  the 
  cuckoo 
  among 
  birds. 
  

  

  The 
  last 
  statement 
  of 
  Professor 
  Westwood 
  is, 
  however, 
  not 
  justified 
  

   by 
  Dufour's 
  observations. 
  On 
  the 
  contrary, 
  Dufour 
  expressly 
  states 
  

   that 
  he 
  did 
  not 
  observe 
  upon 
  what 
  the 
  larva 
  fed 
  ; 
  the 
  inference 
  which 
  

   he 
  draws 
  is 
  based 
  upon 
  the 
  analogy 
  of 
  Anthrax,™ 
  and 
  he 
  inferred 
  that 
  it 
  

   was 
  upon 
  the 
  larvae 
  of 
  Colletes 
  that 
  the 
  grub 
  fed 
  ; 
  quite 
  a 
  different 
  thing 
  

   from 
  being 
  a 
  cuckoo 
  in 
  the 
  nest 
  and 
  feeding 
  only 
  upon 
  the 
  pollen. 
  

   There 
  is, 
  in 
  Dufour's 
  paper, 
  no 
  evidence 
  to 
  prove 
  that 
  the 
  Bombylius 
  

   larva 
  was 
  found 
  in 
  the 
  cocoons, 
  or 
  even 
  in 
  the 
  cells 
  of 
  the 
  bee; 
  he 
  

   states, 
  in 
  fact, 
  that 
  he 
  failed 
  to 
  find 
  it 
  there, 
  but 
  found 
  it 
  among 
  the 
  

   clearings 
  (dtblais) 
  which 
  he 
  had 
  made 
  in 
  digging 
  out 
  the 
  nests. 
  Prof. 
  

   Westwood 
  himself 
  found 
  numbers 
  of 
  Bombylius 
  medius 
  flying 
  in 
  asso- 
  

   ciation 
  with 
  a 
  species 
  of 
  Andrena 
  in 
  the 
  unpaved 
  Forum 
  Triangulare 
  of 
  

   Pompeii, 
  and 
  found 
  at 
  the 
  same 
  spot 
  the 
  pupa-shell 
  of 
  the 
  fly 
  protuding 
  

   from 
  the 
  ground. 
  

  

  Pr. 
  Packard 
  ( 
  u 
  Guide, 
  *' 
  &c, 
  p. 
  397) 
  states 
  that 
  " 
  a 
  species 
  [of 
  Bomby- 
  

   lius] 
  is 
  known 
  in 
  England 
  to 
  lay 
  its 
  eggs 
  at 
  the 
  opening 
  of 
  the 
  holes 
  of 
  

   Andrena, 
  whose 
  larvae 
  and 
  pupae 
  are 
  devoured 
  by 
  the 
  larvae 
  of 
  the 
  fly." 
  

   But 
  no 
  authority 
  is 
  given 
  for 
  the 
  statement. 
  

  

  Messrs. 
  Allen 
  and 
  Underbill, 
  in 
  Science 
  Gossip, 
  1875, 
  p. 
  SO, 
  express 
  

   their 
  belief 
  that 
  the 
  Bombylii 
  are 
  parasitic 
  on 
  humble-bees. 
  In 
  the 
  

   volume 
  for 
  1876, 
  p. 
  171, 
  they 
  say 
  (speaking 
  of 
  Sitaris) 
  : 
  

  

  In 
  relation 
  to 
  the 
  larva 
  of 
  this 
  beetle, 
  we 
  would 
  remark 
  that 
  this 
  year 
  we 
  have 
  found 
  

   it 
  clinging 
  to 
  Bombylii. 
  This 
  is 
  i; 
  circumstantial 
  evidence 
  n 
  that 
  Bombylii 
  frequent 
  the 
  

   nests 
  of 
  Anthophora 
  to 
  lay 
  their 
  eggs, 
  since 
  Sitaris 
  itself, 
  from 
  its 
  manner 
  of 
  life, 
  can- 
  

   not 
  be 
  the 
  parasite 
  of 
  a 
  fly, 
  but 
  only 
  of 
  a 
  bee. 
  

  

  Locust 
  eggs 
  might 
  well 
  have 
  been 
  in 
  the 
  spots 
  where 
  Lucas, 
  Dufour, 
  

   and 
  Westwood 
  found 
  the 
  Bombylius. 
  

  

  From 
  all 
  these 
  notes, 
  it 
  is 
  clear 
  that 
  the 
  true 
  habit 
  of 
  Bombyliid 
  larvae 
  

   had 
  not 
  been 
  clearly 
  ascertained. 
  That 
  they 
  preyed 
  parasitically 
  on 
  

   nest 
  building 
  Hymenoptera 
  was 
  rendered 
  probable 
  by 
  what 
  was 
  known 
  

   of 
  the 
  parasitism 
  of 
  the 
  allied 
  Anthracids; 
  but 
  we 
  had 
  only 
  assump- 
  

   tion 
  without 
  proof, 
  and 
  the 
  experience 
  we 
  now 
  record 
  weakens 
  the 
  force 
  

   of 
  the 
  assumption. 
  

  

  In 
  his 
  " 
  Western 
  Diptera" 
  (1. 
  c. 
  p. 
  243) 
  Baron 
  Osten 
  Sacken 
  gives 
  

   references 
  to 
  the 
  published 
  account 
  of 
  the 
  parasitism 
  of 
  the 
  Anthracid 
  

   genus 
  Argyramccba 
  within 
  the 
  nests 
  of 
  Cemonus 
  and 
  Chalicidoma, 
  cites 
  

  

  XH 
  It 
  has 
  been 
  clearly 
  ascertained, 
  and 
  is 
  well 
  known 
  that 
  Anthrax 
  feeds 
  in 
  the 
  larval 
  

   state 
  upon 
  the 
  young 
  of 
  certain 
  bees. 
  The 
  larva 
  of 
  the 
  Anthrax 
  before 
  attaining 
  its 
  

   own 
  full 
  growth 
  and 
  before 
  destroying 
  its 
  host 
  must 
  await 
  the 
  full 
  growth 
  of 
  the 
  

   latter, 
  as 
  it 
  has, 
  by 
  several 
  observers, 
  been 
  bred 
  from 
  the 
  cocoons 
  of 
  the 
  insects 
  upon 
  

   which 
  it 
  was 
  parasitic. 
  

  

  