﻿470 
  

  

  at 
  a 
  height 
  of 
  3 
  or 
  4 
  feet, 
  the 
  number 
  varying 
  from 
  1 
  on 
  every 
  54 
  acres 
  

   to 
  3 
  on 
  27 
  acres, 
  according 
  to 
  the 
  amount 
  of 
  damage 
  done 
  by 
  the 
  larvae 
  

   to 
  the 
  winter-crops 
  of 
  the 
  previous 
  year. 
  In 
  South 
  Russia 
  the 
  troughs 
  

   are 
  usually 
  put 
  on 
  fallow-fields, 
  but 
  the 
  Station 
  decided 
  to 
  put 
  them 
  

   on 
  winter-sown 
  fields, 
  w^hich 
  were 
  injured 
  last 
  year 
  and 
  where 
  the 
  

   moths 
  might 
  be 
  expected. 
  

  

  The 
  total 
  number 
  of 
  insects 
  caught 
  in 
  21 
  troughs 
  w^as 
  860,843, 
  of 
  

   which 
  86'36 
  per 
  cent, 
  w^ere 
  Euxoa 
  segetum, 
  and 
  3'72 
  per 
  cent. 
  Feltia 
  

   exdamationis. 
  It 
  is 
  estimated 
  that 
  this 
  number 
  of 
  insects 
  could 
  have 
  

   produced 
  77|- 
  millions 
  of 
  larvae. 
  The 
  total 
  cost 
  of 
  the 
  experiment, 
  

   for 
  which 
  58 
  cwt. 
  of 
  molasses 
  were 
  used, 
  including 
  wages, 
  etc., 
  was 
  

   £66 
  85. 
  Od., 
  36 
  lb. 
  of 
  molasses 
  being 
  sufficient 
  for 
  one 
  trough 
  for 
  the 
  

   whole 
  period. 
  The 
  experiment 
  is 
  considered 
  to 
  have 
  successfully 
  

   convinced 
  the 
  population 
  of 
  the 
  utility 
  of 
  this 
  remedy. 
  An 
  index 
  

   of 
  81 
  species 
  of 
  insects, 
  caught 
  on 
  molasses, 
  in 
  the 
  government 
  of 
  Tula, 
  

   during 
  1910-1913 
  is 
  appended. 
  

  

  RiMSKY-KoRSAKov 
  (M. 
  N.). 
  Msosowibi 
  , 
  Bpeflflm'm 
  xn"b5Hbiivii» 
  sjiaKawb 
  

   BTj 
  Pocc'im. 
  [Chalcids 
  of 
  the 
  genus 
  Isosoma 
  injurious 
  to 
  grain 
  

   crops 
  in 
  Russia.]— 
  « 
  TpyAbi 
  Bwpo 
  no 
  3HTOMonoriM 
  yseHaro 
  

   KOMMTBTa 
  fnae. 
  Ynpae. 
  3. 
  M 
  3.» 
  [Memoirs 
  of 
  the 
  Bureau 
  of 
  

   Entomology 
  of 
  the 
  Scientific 
  Committee 
  of 
  the 
  Central 
  Board 
  of 
  

   Land 
  Administration 
  and 
  AgriciiUiire], 
  St. 
  Petersburg, 
  1914, 
  x, 
  

   no. 
  Jl, 
  84 
  pp., 
  50 
  figs., 
  3 
  pis. 
  

  

  This 
  work 
  is 
  the 
  result 
  of 
  investigations 
  on 
  Isosoma 
  conducted 
  by 
  

   the 
  author 
  in 
  1897-1898 
  in 
  the 
  government 
  of 
  Cherson, 
  he 
  having 
  

   been 
  specially 
  sent 
  for 
  this 
  purpose 
  by 
  the 
  Bureau 
  of 
  Entomology 
  

   of 
  the 
  Scientific 
  Committee 
  of 
  the 
  Central 
  Board 
  of 
  Land 
  Adminis- 
  

   tration 
  and 
  Agriculture. 
  The 
  delay 
  in 
  the 
  publication 
  of 
  the 
  report 
  

   has 
  been 
  chiefly 
  owing 
  to 
  the 
  difficulty 
  of 
  the 
  identification 
  of 
  the 
  

   parasites 
  of 
  these 
  insects. 
  The 
  author 
  points 
  out 
  that 
  the 
  biology 
  

   of 
  Isoso7na 
  in 
  Europe 
  is 
  as 
  yet 
  practically 
  unknown. 
  

  

  The 
  genera 
  Isosoma, 
  Philachyra 
  and 
  some 
  others, 
  differ 
  from 
  the 
  

   remaining 
  genera 
  of 
  Eurytomidae 
  which 
  are 
  parasitic 
  on 
  insects 
  and 
  

   other 
  Arthropods, 
  in 
  that 
  they 
  are 
  phytophagous 
  and 
  frequently 
  cause 
  

   serious 
  damage 
  to 
  plants. 
  The 
  author 
  gives 
  a 
  general 
  description 
  

   of 
  the 
  imago, 
  eggs, 
  larvae 
  and 
  pupae 
  of 
  these 
  insects 
  and 
  refers 
  to 
  

   the 
  history 
  of 
  their 
  discovery. 
  Some 
  other 
  representatives 
  of 
  the 
  

   Chalcidoidea 
  (Agaonidae, 
  Torymidae) 
  also 
  breed 
  on 
  plants. 
  Five 
  

   species 
  of 
  Isdsoma 
  w^ere 
  found 
  by 
  the 
  author 
  in 
  the 
  government 
  of 
  

   Cherson. 
  

  

  Isosoma 
  rossicum, 
  sp. 
  n. 
  ; 
  having 
  described 
  the 
  males 
  and 
  female 
  

   of 
  this 
  species 
  and 
  pointed 
  out 
  the 
  difference 
  between 
  I. 
  rossicum 
  and 
  

   I. 
  hordei, 
  Harris, 
  for 
  which 
  this 
  species 
  was 
  mistaken 
  by 
  Portchinsky 
  

   and 
  Lindeman, 
  the 
  author 
  proceeds 
  to 
  describe 
  the 
  development 
  

   and 
  life-history 
  of 
  these 
  insects. 
  The 
  adults 
  are 
  on 
  the 
  wing 
  near 
  

   grain 
  fields 
  during 
  the 
  first 
  half 
  of 
  June 
  ; 
  in 
  captivity 
  the 
  author 
  

   has 
  reared 
  adults 
  in 
  February 
  and 
  March. 
  Both 
  sexes 
  eat 
  the 
  pollen 
  

   and 
  drink 
  the 
  nectar 
  of 
  flowers. 
  Adults 
  seem 
  to 
  live 
  only 
  about 
  a 
  

   fortnight. 
  The 
  eggs 
  are 
  deposited 
  inside 
  the 
  stems 
  of 
  rye 
  and 
  wheat, 
  

   chiefly 
  in 
  the 
  internodes 
  or 
  on 
  the 
  nodes 
  themselves. 
  The 
  maximum 
  

   number 
  of 
  eggs 
  laid 
  on 
  one 
  internode 
  is 
  12, 
  as 
  shown 
  by 
  the 
  number 
  

  

  