﻿631 
  

  

  18 
  days 
  after 
  birth. 
  A. 
  sorghi 
  secretes 
  a 
  sugary 
  substance, 
  on 
  which 
  

   a 
  rather 
  dense 
  fungus 
  growth 
  develops, 
  which 
  is 
  attractive 
  to 
  

   numerous 
  Diptera 
  and 
  Hymenoptera 
  and 
  to 
  an 
  ant 
  of 
  the 
  genus 
  

   Acantholepis. 
  A. 
  maidis 
  was 
  found 
  both 
  on 
  maize 
  and 
  sorghum, 
  

   but 
  appears 
  to 
  prefer 
  the 
  latter. 
  It 
  seems 
  to 
  be 
  most 
  abundant 
  in 
  

   the 
  middle 
  of 
  the 
  rainy 
  season 
  (July- 
  August). 
  Laboratory 
  experi- 
  

   ments 
  show 
  that 
  A. 
  niaidis 
  Uves 
  about 
  30 
  days. 
  Larvae 
  are 
  produced 
  

   after 
  5 
  days 
  at 
  the 
  rate 
  of 
  from 
  4 
  to 
  6 
  every 
  24 
  hours 
  during 
  from 
  9 
  to 
  

   12 
  days. 
  After 
  this, 
  fertihty 
  rapidly 
  decreases 
  and 
  ceases 
  about 
  the 
  

   twentieth 
  day 
  of 
  Hfe. 
  Migratory 
  individuals 
  acquire 
  wings 
  in 
  about 
  

   5 
  or 
  6 
  days 
  and 
  produce 
  new 
  larvae 
  within 
  24 
  hours. 
  In 
  one 
  case 
  

   the 
  winged 
  form 
  occurred 
  after 
  three 
  apterous 
  generations, 
  in 
  another 
  

   four 
  successive 
  generations 
  were 
  bred 
  without 
  obtaining 
  winged 
  

   insects. 
  Natural 
  enemies 
  abound, 
  and 
  the 
  following 
  list 
  only 
  includes 
  

   those 
  noticed 
  at 
  Kouli 
  Koro 
  : 
  — 
  Coleoptera 
  : 
  Chilomenes 
  vicitia, 
  

   Muls., 
  Exochomusfuvipes, 
  Thunb., 
  var. 
  troberti, 
  Muls., 
  Scymnus 
  plebeiuSy 
  

   Weise. 
  Diptera 
  : 
  Paragus 
  serratus, 
  F., 
  P. 
  borbonicus, 
  Macq., 
  

   P. 
  longiventris, 
  Lw., 
  Xanthogramma 
  aegyptium, 
  Wied., 
  Leucopis 
  sp. 
  

   Neuroptera 
  : 
  Chrysopa 
  incongrua, 
  Nav., 
  C. 
  oralis, 
  Nav., 
  C. 
  vuilleti, 
  Nav. 
  

   Regarding 
  the 
  Chrysopidae, 
  it 
  is 
  difficult 
  to 
  decide 
  whether 
  they 
  are 
  

   really 
  beneficial 
  or 
  injurious, 
  but 
  the 
  authors 
  incline 
  to 
  the 
  latter 
  

   view. 
  One 
  entomophytic 
  fungus 
  has 
  been 
  noticed 
  in 
  the 
  Sudan. 
  

   Many 
  A. 
  maidis 
  are 
  destroyed 
  by 
  the 
  rains, 
  while 
  A. 
  sorghi 
  suffers 
  

   when 
  a 
  very 
  dry 
  winter 
  causes 
  the 
  sorghum 
  stubble 
  to 
  wither 
  and 
  die 
  

   rapidly. 
  From 
  a 
  practical 
  point 
  of 
  view, 
  control 
  need 
  be 
  undertaken 
  

   against 
  A. 
  sorghi 
  alone, 
  as 
  the 
  injury 
  due 
  to 
  A. 
  maidis 
  is 
  not 
  of 
  economic 
  

   importance. 
  The 
  use 
  of 
  insecticides 
  need 
  not 
  be 
  considered, 
  so 
  far 
  

   as 
  the 
  Sudanese 
  regions 
  are 
  concerned. 
  Control 
  should 
  be 
  based 
  on 
  

   two 
  facts 
  : 
  that 
  A. 
  sorghi 
  confines 
  itself 
  to 
  sorghum, 
  and 
  that 
  the 
  

   enemies 
  of 
  A. 
  sorghi 
  multiply 
  not 
  only 
  at 
  the 
  cost 
  of 
  A. 
  maidis, 
  but 
  

   also 
  of 
  Siphonophora 
  leptadeniae. 
  All 
  the 
  old 
  stools 
  of 
  sorghum 
  

   should 
  be 
  dug 
  up 
  and 
  burned 
  immediately 
  after 
  the 
  harvest. 
  Planta- 
  

   ations 
  which 
  have 
  remained 
  unproductive, 
  and 
  consequently 
  

   unharvested, 
  should 
  be 
  dealt 
  with 
  at 
  an 
  earher 
  date. 
  Where 
  sorghum 
  

   is 
  very 
  badly 
  attacked 
  it 
  should 
  be 
  replaced 
  by 
  the 
  small 
  millet 
  

   (Pennisetum 
  spicaium). 
  Land 
  shaded 
  by 
  trees 
  with 
  dense 
  fohage 
  

   {Ficus, 
  Cola 
  cordifoila, 
  Parkia, 
  Tamarind, 
  etc.) 
  should 
  not 
  be 
  sown 
  

   with 
  sorghum, 
  as 
  no 
  good 
  crop 
  will 
  be 
  produced 
  and 
  the 
  stems 
  neglected 
  

   by 
  the 
  cultivator 
  will 
  prove 
  a 
  breeding 
  place 
  for 
  aphids, 
  unless 
  the 
  

   district 
  is 
  one 
  of 
  those 
  where 
  stubble 
  destruction 
  is 
  compulsory. 
  The 
  

   method 
  of 
  indirect 
  control 
  by 
  planting 
  Leptadenia 
  lancifolia, 
  Decaisne, 
  

   is 
  described 
  and 
  a 
  description 
  of 
  Siphonophora 
  leptadeniae, 
  sp. 
  nov., 
  

   is 
  given 
  [see 
  this 
  Review, 
  Ser. 
  A, 
  ii, 
  pp. 
  396, 
  588]. 
  

  

  P. 
  F. 
  Genossenschaftliche 
  Bekampfungsversuche 
  des 
  Heuwurms 
  mit 
  

   Nicotinbruhe 
  zu 
  Grevenmacher. 
  [Co-operative 
  trials 
  in 
  controUing 
  

   the 
  first 
  generation 
  of 
  the 
  vine 
  moth 
  with 
  nicotin 
  at 
  Grevenma- 
  

   cher.] 
  — 
  Luxembiirger 
  Weinztg., 
  Grevenmacher, 
  ii, 
  no. 
  11, 
  1st 
  June 
  

   1914, 
  pp. 
  170-172. 
  

  

  In 
  Luxemburg 
  two 
  vine-growers' 
  syndicates 
  have 
  undertaken 
  control 
  

   of 
  Clysia 
  ambiguella 
  in 
  two 
  locaHties. 
  In 
  one 
  of 
  these 
  spraying 
  began 
  

   on 
  22nd 
  May, 
  though 
  very 
  few 
  moths 
  had 
  been 
  found 
  in 
  the 
  trap- 
  

   pots 
  and 
  captures 
  were 
  decreasing 
  in 
  spite 
  of 
  the 
  warm 
  weather. 
  

  

  