﻿350 
  

  

  KuRDJuMov 
  (N. 
  v.). 
  flpoean 
  wiyxa 
  m 
  OsMMan 
  Myxa. 
  [Adia 
  genitalis, 
  

   Schnabl, 
  and 
  Leptohylemyia 
  coarctata, 
  Fall.] 
  — 
  « 
  Tpyflbl 
  FlOJlTaB- 
  

   CKOM 
  CeJlbCK0-X03flMCTBeHH0M 
  OnblTHOM 
  CTaHUiM.» 
  [Studies 
  from 
  

   the 
  Poltava 
  Agricultural 
  Experimental 
  Station], 
  no. 
  21, 
  (Part 
  IX 
  

   of 
  the 
  Publications 
  of 
  the 
  Branch 
  of 
  Agricultural 
  Entomology), 
  

   Poltava, 
  1914, 
  43 
  pp., 
  27 
  figs. 
  

  

  Adia 
  genitalis 
  has 
  not 
  been 
  known 
  previously 
  as 
  a 
  pest 
  and 
  has 
  been 
  

   only 
  recently 
  described 
  by 
  the 
  late 
  Dr. 
  I. 
  Schnabl 
  and 
  Dr. 
  H. 
  Dziedziki. 
  

   It 
  is 
  assumed 
  that 
  this 
  fly 
  is 
  spread 
  over 
  the 
  whole 
  of 
  Europe, 
  accom- 
  

   panying 
  the 
  cultivation 
  of 
  wheat. 
  It 
  is 
  distinguished 
  from 
  Leptohy- 
  

   lemyia 
  coarctata 
  by 
  the 
  velvet-black 
  colour 
  of 
  its 
  body 
  and 
  parts 
  of 
  its 
  

   wings. 
  In 
  1913, 
  the 
  first 
  specimen, 
  a 
  male, 
  was 
  caught 
  in 
  the 
  

   fields 
  on 
  the 
  14th 
  April, 
  a 
  date 
  coinciding 
  with 
  the 
  appearance 
  of 
  the 
  

   seedlings 
  of 
  summer 
  w^heat. 
  The 
  number 
  of 
  insects 
  in 
  the 
  fields 
  

   increased 
  after 
  that 
  date, 
  reaching 
  its 
  maximum 
  on 
  the 
  lst-3rd 
  May, 
  

   after 
  which 
  they 
  decreased, 
  and 
  after 
  the 
  1st 
  June 
  no 
  flies 
  were 
  left 
  

   alive 
  either 
  in 
  the 
  fields 
  or 
  in 
  the 
  laboratory. 
  It 
  has 
  not 
  been 
  estab- 
  

   lished 
  what 
  food 
  the 
  flies 
  take 
  in 
  the 
  open 
  ; 
  in 
  the 
  laboratory 
  they 
  fed 
  

   on 
  sugar 
  syrup. 
  The 
  eggs 
  were 
  found 
  for 
  the 
  first 
  time 
  in 
  the 
  spring 
  

   of 
  1912 
  ; 
  they 
  are 
  laid 
  behind 
  the 
  sheath 
  of 
  the 
  leaf 
  as 
  is 
  the 
  case 
  with 
  

   Oscinis 
  frit, 
  but 
  the 
  structure 
  of 
  the 
  shell 
  and 
  the 
  size 
  is 
  different. 
  It 
  

   was 
  only 
  in 
  1913 
  that 
  the 
  identity 
  of 
  the 
  eggs 
  w^as 
  established, 
  when 
  

   they 
  were 
  obtained 
  in 
  the 
  laboratory. 
  The 
  author 
  describes 
  the 
  egg 
  

   and 
  the 
  process 
  of 
  oviposition, 
  which 
  has 
  been 
  twice 
  observed 
  in 
  the 
  

   insectarium. 
  Examination 
  of 
  summer 
  wheat 
  in 
  the 
  fields 
  has 
  show^n 
  

   that 
  sometimes 
  the 
  eggs 
  are 
  laid 
  behind 
  the 
  leaf 
  -stalks 
  and 
  that 
  on 
  

   some 
  plants 
  two 
  eggs 
  are 
  deposited 
  ; 
  but 
  only 
  one 
  larva 
  can 
  develop 
  

   in 
  one 
  stalk. 
  The 
  duration 
  of 
  the 
  egg 
  stage 
  depends 
  on 
  the 
  temperature, 
  

   a 
  table 
  showing 
  the 
  time 
  of 
  hatching 
  at 
  various 
  temperatures 
  in 
  the 
  

   thermostat, 
  ranging 
  from 
  10*4° 
  C. 
  to 
  25° 
  C. 
  is 
  given, 
  from 
  which 
  it 
  

   appears 
  that 
  the 
  period 
  varied 
  from 
  2 
  to 
  8 
  days 
  ; 
  a 
  temperature 
  of 
  

   over 
  35° 
  C. 
  kills 
  the 
  eggs. 
  In 
  1912, 
  the 
  first 
  larva 
  was 
  found 
  on 
  wheat 
  

   on 
  the 
  30th 
  May, 
  and 
  the 
  last 
  on 
  the 
  28th 
  June. 
  In 
  1913, 
  the 
  first 
  

   larvae 
  were 
  noticed 
  on 
  the 
  30th 
  April 
  and 
  the 
  last 
  on 
  the 
  27th 
  June. 
  

   The 
  author 
  gives 
  a 
  table 
  showing 
  the 
  number 
  of 
  eggs, 
  larvae 
  in 
  their 
  

   various 
  stages 
  and 
  puparia 
  found 
  in 
  the 
  open 
  from 
  the 
  14th 
  May 
  to 
  

   the 
  24th 
  June 
  1913. 
  The 
  larvae 
  moult 
  twice, 
  passing 
  through 
  three 
  

   stages, 
  which 
  are 
  fully 
  described. 
  In 
  1913, 
  the 
  first 
  puparium 
  was 
  

   found 
  on 
  28th 
  May 
  ; 
  it 
  appears 
  that 
  about 
  75 
  per 
  cent, 
  of 
  the 
  larvae 
  

   leave 
  the 
  plant 
  and 
  pupate 
  in 
  the 
  earth 
  at 
  a 
  depth 
  of 
  lJ-2 
  inches 
  ; 
  

   the 
  remainder 
  pupate 
  on 
  the 
  plants, 
  where 
  their 
  puparia 
  have 
  been 
  

   found. 
  The 
  insect 
  winters 
  in 
  this 
  stage, 
  emerging 
  as 
  an 
  imago 
  only 
  

   in 
  April 
  of 
  the 
  next 
  year. 
  

  

  Having 
  emerged 
  from 
  the 
  egg, 
  the 
  larva 
  bores 
  its 
  way 
  through 
  the 
  

   pith 
  of 
  the 
  stalk 
  to 
  the 
  point 
  w^here 
  the 
  upper 
  leaf, 
  then 
  still 
  rolled 
  into 
  

   a 
  tube, 
  is 
  situated. 
  From 
  the 
  point 
  of 
  entrance 
  into 
  the 
  central 
  leaf, 
  

   it 
  moves 
  downwards 
  cutting 
  a 
  spiral 
  way, 
  which 
  has 
  two 
  or 
  three 
  full 
  

   turns. 
  Having 
  reached 
  the 
  tillering 
  point 
  (knot) 
  the 
  larva 
  gnaws 
  

   through 
  its 
  summit, 
  thus 
  severing 
  the 
  connection 
  between 
  the 
  

   central 
  part 
  of 
  the 
  stalk 
  and 
  the 
  root. 
  This 
  part 
  of 
  the 
  stalk 
  remains 
  

   inside 
  the 
  uninjured 
  outer 
  leaf. 
  The 
  object 
  of 
  this 
  tunnel 
  is 
  apparently 
  

   to 
  guarantee 
  a 
  food 
  supply 
  for 
  the 
  larva 
  during 
  the 
  later 
  period 
  of 
  its 
  

  

  