﻿669 
  

  

  also 
  out 
  of 
  the 
  obscure 
  state 
  of 
  our 
  knowledge 
  of 
  its 
  biology. 
  A 
  

   minute 
  description 
  of 
  all 
  the 
  stages 
  of 
  the 
  weevil 
  is 
  given. 
  

  

  0. 
  ligustici 
  is 
  found 
  everywhere 
  in 
  Europe, 
  except 
  in 
  the 
  most 
  

   southern 
  parts, 
  while 
  in 
  Russia, 
  Tobolsk 
  appears 
  to 
  be 
  its 
  eastern 
  

   limit. 
  The 
  w^eevils 
  hibernate 
  in 
  the 
  soil, 
  appearing 
  in 
  spring 
  during 
  

   April. 
  In 
  the 
  government 
  of 
  Ekaterinoslav, 
  a 
  great 
  migration 
  

   takes 
  place 
  during 
  May, 
  the 
  weevils 
  searching 
  for 
  such 
  food-plants 
  

   as 
  lucerne, 
  Melilotus 
  officinalis 
  or 
  M. 
  alba. 
  During 
  this 
  time 
  

   they 
  do 
  a 
  great 
  amount 
  of 
  damage, 
  though 
  less 
  than 
  that 
  done 
  sub- 
  

   sequently 
  by 
  the 
  larvae. 
  Oviposition 
  starts 
  in 
  the 
  middle 
  of 
  May, 
  

   and 
  the 
  eggs 
  are 
  deposited 
  at 
  a 
  depth 
  of 
  1 
  to 
  2 
  inches 
  round 
  

   the 
  roots 
  of 
  the 
  food-plants. 
  At 
  first 
  the 
  larvae 
  make 
  unimportant 
  

   wounds 
  in 
  the 
  collars 
  of 
  the 
  plants, 
  but 
  very 
  soon 
  burrow 
  deeper 
  into 
  

   the 
  earth 
  in 
  search 
  of 
  the 
  ends 
  of 
  the 
  roots, 
  on 
  the 
  parenchyma 
  of 
  

   which 
  they 
  feed. 
  The 
  depth 
  at 
  which 
  the 
  larvae 
  hve 
  varies 
  from 
  the 
  

   surface 
  to 
  20 
  inches 
  below 
  it, 
  according 
  to 
  the 
  moisture 
  in 
  the 
  soil, 
  etc. 
  

   After 
  heavy 
  rains, 
  they 
  come 
  near 
  the 
  surface 
  owing 
  to 
  lack 
  of 
  air. 
  

   The 
  larval 
  stage 
  lasts 
  a 
  whole 
  year 
  and 
  pupation 
  takes 
  place 
  in 
  the 
  

   second 
  half 
  of 
  May 
  and 
  during 
  June, 
  the 
  pupal 
  stage 
  lasting 
  from 
  

   3J-4 
  weeks, 
  the 
  average 
  depth 
  at 
  which 
  the 
  pupa 
  are 
  found 
  being 
  

   about 
  11 
  inches. 
  The 
  result 
  of 
  the 
  damage 
  done 
  appears 
  after 
  the 
  

   beginning 
  of 
  August 
  in 
  the 
  form 
  of 
  yellow 
  patches 
  of 
  withered 
  plants. 
  

  

  The 
  following 
  Coleopterous 
  enemies 
  of 
  0. 
  ligustici 
  have 
  been 
  

   recorded 
  : 
  — 
  Calosoma 
  inquisitor, 
  various 
  species 
  of 
  Poecilus 
  and 
  

   Feronia, 
  Hister 
  sinuatus, 
  and 
  Staphylinidae 
  ; 
  in 
  only 
  a 
  few 
  cases 
  

   were 
  weevils 
  found 
  to 
  have 
  been 
  killed 
  by 
  the 
  muscardine 
  fungus. 
  

  

  Preventive 
  remedies 
  against 
  this 
  pest 
  aim 
  at 
  the 
  protection 
  of 
  

   lucerne 
  fields 
  from 
  an 
  invasion 
  by 
  the 
  weevils 
  and 
  consist 
  of 
  (1) 
  spray- 
  

   ing 
  with 
  Paris 
  green 
  of 
  a 
  strip 
  of 
  21-28 
  feet 
  wide 
  round 
  the 
  fields 
  and 
  

   about 
  14 
  feet 
  of 
  the 
  adjoining 
  lands 
  ; 
  a 
  solution 
  of 
  2-3 
  lb. 
  of 
  green 
  

   and 
  6 
  lb. 
  of 
  quickhme 
  in 
  about 
  110 
  gallons 
  of 
  water 
  produced 
  a 
  death 
  

   rate 
  of 
  90 
  per 
  cent, 
  and 
  proved 
  much 
  more 
  effective 
  and 
  less 
  injurious 
  

   to 
  lucerne 
  than 
  61b. 
  of 
  barium 
  chloride 
  and 
  9 
  oz. 
  of 
  joiner's 
  glue 
  

   in 
  11 
  gallons 
  of 
  water, 
  which 
  only 
  killed 
  8 
  per 
  cent, 
  of 
  the 
  weevils. 
  (2) 
  

   Lining 
  the 
  fields 
  with 
  boards 
  laid 
  lengthwise 
  and 
  smeared 
  on 
  the 
  

   outside 
  with 
  a 
  sticky 
  material 
  ; 
  care 
  must 
  be 
  taken 
  that 
  the 
  boards 
  

   are 
  well 
  set 
  in 
  the 
  ground 
  and 
  that 
  the 
  ends 
  fit 
  closely, 
  so 
  that 
  no 
  holes 
  

   are 
  left 
  for 
  the 
  possible 
  passage 
  of 
  weevils 
  ; 
  these 
  boards 
  must 
  be 
  in 
  

   place 
  before 
  the 
  spring 
  migration 
  starts. 
  (3) 
  Trenches 
  round 
  the 
  

   fields, 
  filled 
  with 
  water 
  in 
  places 
  where 
  irrigation 
  is 
  practised, 
  or 
  with 
  

   steep 
  sides 
  and 
  pits 
  along 
  the 
  bottom 
  at 
  intervals 
  where 
  no 
  water 
  is 
  

   available, 
  the 
  weevils 
  being 
  periodically 
  collected 
  and 
  destroyed 
  by 
  

   means 
  of 
  boiling 
  water 
  or 
  by 
  burning 
  with 
  naphtha. 
  

  

  Destructive 
  remedies 
  include 
  (1) 
  spraying 
  with 
  Paris 
  green 
  (4 
  lb. 
  

   of 
  green 
  and 
  4 
  lb. 
  of 
  Hme 
  in 
  110 
  gallons 
  of 
  water) 
  ; 
  (2) 
  ploughing 
  infested 
  

   spots 
  to 
  a 
  depth 
  of 
  10-11 
  inches 
  at 
  the 
  beginning 
  of 
  summer, 
  in 
  order 
  

   to 
  destroy 
  the 
  pupae, 
  but 
  in 
  this 
  case 
  it 
  is 
  first 
  necessary 
  to 
  ascertain 
  

   that 
  the 
  majority 
  of 
  the 
  larvae 
  have 
  already 
  pupated 
  ; 
  (3) 
  handpicking 
  

   and 
  collection 
  of 
  the 
  beetles 
  in 
  spring. 
  

  

  A 
  supplementary 
  chapter 
  deals 
  with 
  the 
  parthenogenesis 
  of 
  

   0. 
  ligustici 
  and 
  describes 
  the 
  author's 
  experiments, 
  which 
  have 
  

   confirmed 
  this 
  phenomenon, 
  and, 
  according 
  to 
  Silantiev 
  this 
  is 
  also 
  

   true 
  in 
  the 
  case 
  of 
  0. 
  turca. 
  

  

  