﻿MYCETOPHILID 
  FLIES 
  AS 
  PESTS 
  OF 
  THE 
  CUCUMBER 
  PLANT. 
  

  

  257 
  

  

  the 
  soil. 
  At 
  this 
  time 
  the 
  soil 
  of 
  the 
  pots 
  was 
  teeming 
  with 
  minute 
  winged 
  flies, 
  

   which 
  proved 
  to 
  be 
  males 
  of 
  both 
  long- 
  winged 
  and 
  short-winged 
  types. 
  

  

  Fig. 
  6. 
  Pnyxia 
  scabiei, 
  Hopk. 
  >( 
  J, 
  short-winged 
  form, 
  x 
  33. 
  

  

  On 
  20th 
  January 
  several 
  females 
  made 
  their 
  appearance 
  in 
  the 
  soil 
  of 
  the 
  pots, 
  

   one 
  being 
  found 
  at 
  a 
  depth 
  of 
  quite 
  1 
  in. 
  below 
  the 
  soil 
  surface. 
  Three 
  males 
  and 
  

   three 
  females 
  were 
  caught 
  in 
  copula 
  and 
  placed 
  in 
  separate 
  glass 
  tubes, 
  one 
  containing 
  

   moist 
  soil, 
  one 
  horse 
  manure, 
  and 
  the 
  third 
  a 
  piece 
  of 
  cucumber 
  stem 
  without 
  soil. 
  

  

  Fig. 
  7. 
  Plastosciara 
  pemiciosa, 
  Edwards, 
  ^. 
  X 
  33. 
  

  

  All 
  three 
  females 
  had 
  deposited 
  some 
  eggs 
  by 
  23rd 
  January, 
  but 
  those 
  laid 
  in 
  the 
  third 
  

   tube 
  had 
  been 
  deposited 
  on 
  the 
  glass, 
  and 
  not 
  on 
  the 
  cucumber 
  stem, 
  and 
  both 
  male 
  

   and 
  female 
  were 
  dead. 
  In 
  the 
  other 
  two 
  tubes 
  the 
  females 
  lived 
  till 
  the 
  day 
  following, 
  

   and 
  had 
  then 
  deposited 
  28 
  and 
  25 
  eggs 
  respectively, 
  a 
  few 
  millimetres 
  below 
  the 
  soil 
  

   surface. 
  The 
  eggs 
  are 
  oval, 
  white 
  and 
  shining, 
  and 
  measure 
  0-28 
  mm. 
  in 
  length. 
  

  

  Conditions 
  conducive 
  to 
  Attack. 
  

  

  It 
  is 
  now 
  practically 
  certain 
  that 
  the 
  larvae 
  (doubtfully 
  the 
  eggs) 
  are 
  brought 
  

   into 
  the 
  houses 
  with 
  manure 
  at 
  the 
  time 
  of 
  planting. 
  In 
  more 
  than 
  one 
  nursery 
  in 
  the 
  

  

  (8053) 
  s 
  2 
  

  

  