﻿THE 
  LARVAL 
  AND 
  PUPAL 
  STAGES 
  OF 
  THE 
  BIBIOXIDAE 
  — 
  PART 
  II. 
  195 
  

  

  Differences 
  between 
  the 
  Larvae 
  and 
  Pupae 
  of 
  Bibio 
  and 
  Dilophus. 
  

  

  The 
  larvae 
  and 
  pupae 
  of 
  these 
  two 
  genera, 
  in 
  so 
  far 
  as 
  the 
  various 
  species 
  have 
  been 
  

   studied, 
  appear 
  to 
  be 
  quite 
  easily 
  distinguishable. 
  The 
  newly 
  hatched 
  larvae 
  of 
  Bibio 
  

   are 
  characterised 
  by 
  their 
  very 
  long 
  setae, 
  the 
  larvae 
  of 
  Dilophus 
  at 
  this 
  stage 
  having 
  

   only 
  short 
  setae. 
  They 
  are 
  further 
  distinguishable 
  by 
  the 
  presence 
  of 
  many 
  small 
  

   spines 
  on 
  the 
  cuticle 
  in 
  Bibio, 
  Dilophus 
  having 
  groups 
  of 
  1-4 
  similar 
  but 
  still 
  smaller 
  

   spines 
  in 
  the 
  same 
  position 
  ; 
  also 
  the 
  Bibio 
  larva 
  has 
  a 
  single 
  median 
  process 
  at 
  the 
  

   anterior 
  end 
  of 
  the 
  labium, 
  the 
  Dilophus 
  larvae 
  having 
  a 
  pair 
  of 
  processes 
  in 
  this 
  

   position. 
  The 
  newly 
  hatched 
  larvae 
  of 
  these 
  genera 
  agree 
  in 
  the 
  presence 
  of 
  a 
  

   single 
  pair 
  of 
  spiracles 
  situated 
  on 
  the 
  twelfth 
  segment. 
  

  

  The 
  fully 
  grown 
  larvae 
  are 
  also 
  quite 
  readily 
  distinguishable. 
  The 
  most 
  striking 
  

   difference 
  is 
  the 
  smaller 
  number 
  of 
  processes 
  in 
  Dilophus 
  larvae 
  as 
  compared 
  with 
  those 
  

   of 
  Bibio. 
  They 
  may 
  also 
  be 
  distinguished 
  by 
  the 
  posterior 
  spiracles 
  of 
  Dilophus 
  

   having 
  3 
  openings, 
  while 
  those 
  of 
  Bibio 
  have 
  only 
  2. 
  In 
  addition 
  there 
  is 
  a 
  well- 
  

   developed 
  median 
  process 
  at 
  the 
  anterior 
  end 
  of 
  the 
  labium, 
  which, 
  in 
  the 
  species 
  

   so 
  far 
  examined, 
  is 
  absent 
  or 
  very 
  slightly 
  developed 
  in 
  Bibio. 
  

  

  Male 
  pupae 
  are 
  distinguishable 
  by 
  the 
  presence 
  of 
  3 
  well-developed 
  conical 
  

   processes 
  at 
  the 
  anterior 
  end 
  in 
  Dilophus, 
  instead 
  of 
  the 
  single 
  process 
  in 
  this 
  position 
  

   in 
  Bibio 
  pupae, 
  which 
  in 
  some 
  cases 
  is 
  very 
  slightly 
  developed. 
  Female 
  pupae 
  of 
  

   Dilophus 
  have 
  the 
  single 
  median 
  process 
  at 
  the 
  anterior 
  end 
  much 
  better 
  developed 
  

   than 
  has 
  been 
  observed 
  in 
  any 
  Bibio 
  pupa. 
  

  

  References 
  to 
  Literature. 
  

  

  Several 
  references 
  to 
  damage 
  caused 
  by 
  Dilophus 
  larvae 
  to 
  crops 
  have 
  been 
  noticed 
  

   previously. 
  The 
  following 
  additional 
  references 
  may 
  be 
  mentioned 
  : 
  — 
  

  

  Cameron, 
  A. 
  E. 
  (1913). 
  " 
  General 
  Survey 
  of 
  the 
  Insect 
  Fauna 
  of 
  the 
  

   Soil." 
  Journ. 
  Econ. 
  Biol, 
  viii, 
  3. 
  

  

  Curtis, 
  J. 
  (1844). 
  " 
  Dilophus 
  febrilis." 
  Gardeners' 
  Chronicle. 
  

  

  Morris, 
  H. 
  M. 
  (1917). 
  " 
  The 
  larval 
  and 
  pupal 
  stages 
  of 
  Bibio 
  johannis, 
  

   L." 
  Ann. 
  App. 
  Biol, 
  iv, 
  3, 
  pp. 
  91-114. 
  

  

  Morris, 
  H. 
  M. 
  (1921). 
  " 
  The 
  larval 
  and 
  pupal 
  stages 
  of 
  the 
  Bibionidae." 
  

   Bull. 
  Ent. 
  Res. 
  xii, 
  3, 
  pp. 
  221-232. 
  

  

  