﻿581 
  

  

  hyalinipennis, 
  Costa, 
  is 
  scarcely 
  a 
  pest, 
  but 
  it 
  occurs 
  in 
  large 
  numbers 
  

   in 
  cotton 
  which 
  is 
  being 
  ginned, 
  and 
  the 
  staining 
  due 
  to 
  the 
  crushed 
  

   insects 
  may 
  prove 
  a 
  source 
  of 
  loss. 
  The 
  Pentatomids, 
  Calidea 
  

   apicalis, 
  Schout., 
  Hotea 
  subfasciata, 
  Westw., 
  and 
  Hotea 
  sp., 
  occur 
  

   in 
  the 
  colony, 
  and 
  the 
  Coreid, 
  Serinetha 
  hexophthahna, 
  Thunb., 
  

   is 
  occasionally 
  found 
  on 
  cotton, 
  while 
  the 
  Mirid, 
  Helopeltis 
  

   bergrothi, 
  Renter, 
  was 
  noticed 
  at 
  Amani. 
  Many 
  species 
  of 
  Jassidae 
  

   occur 
  on 
  cotton, 
  Chlorita 
  facialis, 
  Jac, 
  being 
  the 
  species 
  most 
  frequently 
  

   caught 
  in 
  the 
  Mombo 
  Hght-trap 
  trials. 
  Direct 
  control 
  seems 
  im- 
  

   practicable, 
  but 
  the 
  brothers 
  Pentzel 
  state 
  that 
  these 
  insects 
  avoid 
  

   plants 
  visited 
  by 
  ants, 
  and 
  advise 
  the 
  retention 
  of 
  a 
  fallow 
  strip 
  along 
  

   the 
  sides 
  of 
  a 
  cotton 
  field, 
  which 
  ants 
  will 
  occupy. 
  The 
  author 
  believes 
  

   that 
  Aphis 
  sorghi, 
  Theo., 
  is 
  the 
  species 
  responsible 
  for 
  the 
  Mafuta 
  

   disease, 
  which 
  is 
  usually 
  without 
  serious 
  consequences 
  to 
  the 
  crop. 
  

   An 
  exception 
  to 
  this 
  was 
  noticed 
  by 
  the 
  author 
  in 
  1913 
  in 
  the 
  Kilwa 
  

   district, 
  where 
  it 
  appears 
  to 
  have 
  ruined 
  the 
  crops. 
  Spraying 
  with 
  

   nicotin-soap 
  or 
  petroleum 
  emulsion 
  seems 
  to 
  be 
  the 
  only 
  method 
  of 
  

   control. 
  Alesia 
  striata 
  and 
  Chilomenes 
  lunata, 
  F., 
  are 
  natural 
  enemies. 
  

   The 
  CocciDAE 
  observed 
  in 
  German 
  East 
  Africa 
  on 
  cotton 
  are 
  : 
  

   Pseudococcus 
  (Bactylopius) 
  citri, 
  Risso, 
  Pseudococcus 
  (Phenacoccus) 
  

   obticsus, 
  Ldgr., 
  Pseudococcus 
  filamentosus^ 
  CklL, 
  Hemichionaspis 
  

   (Pinnaspis) 
  minor, 
  Mask., 
  Saissetia 
  (Lecanium) 
  nigra, 
  Nietn., 
  and 
  

   undetermined 
  species 
  of 
  Eriococcus, 
  Lecanium 
  and 
  Pulvinaria. 
  

  

  The 
  author 
  concludes 
  by 
  referring 
  to 
  the 
  disinfection 
  of 
  cotton 
  seed, 
  the 
  

   agents 
  mentioned 
  being 
  carbon 
  bisulphide, 
  carbon 
  tetrachloride, 
  naph- 
  

   thahn, 
  corrosive 
  sublimate 
  or 
  seawater. 
  The 
  seed 
  should 
  be 
  disinfected 
  

   as 
  soon 
  as 
  it 
  arrives 
  at 
  the 
  buyer's 
  plantation 
  and 
  stored 
  separately 
  

   from 
  non-disinfected 
  seed 
  in 
  a 
  dry, 
  airy 
  place, 
  not 
  on 
  the 
  ground 
  ; 
  

   carbon 
  bisulphide 
  or 
  carbon 
  tetrachloride 
  are 
  the 
  best 
  disinfectants, 
  

   and 
  to 
  protect 
  the 
  seed 
  from 
  future 
  infestation 
  1 
  per 
  cent, 
  of 
  naph- 
  

   thahn 
  should 
  be 
  mixed 
  thoroughly 
  with 
  it. 
  Where 
  it 
  is 
  impossible 
  

   to 
  keep 
  the 
  store-rooms 
  free 
  from 
  infected 
  seed, 
  disinfection 
  may 
  be 
  

   carried 
  out 
  immediately 
  before 
  sowing 
  by 
  immersing 
  the 
  seed 
  in 
  water 
  

   containing 
  1 
  per 
  1000 
  of 
  corrosive 
  sublimate, 
  the 
  mass 
  being 
  well 
  

   stirred. 
  After 
  half 
  an 
  hour 
  the 
  liquid 
  should 
  be 
  strained 
  off, 
  and 
  

   the 
  seed 
  rinsed 
  and 
  planted 
  without 
  delay. 
  Wooden 
  containers 
  must 
  

   be 
  used, 
  as 
  alloys 
  are 
  formed 
  if 
  metal 
  comes 
  in 
  contact 
  with 
  the 
  

   solution. 
  

  

  Smith 
  (R. 
  E.), 
  Hunt 
  (T. 
  F.) 
  & 
  Nixon 
  (W. 
  H.). 
  Spraying 
  Walnut 
  

   trees 
  for 
  Blight 
  and 
  Aphis 
  Control. 
  — 
  Cal. 
  Univ. 
  Agric. 
  Expt. 
  Sta., 
  

   Berkeley, 
  Circular 
  no. 
  107, 
  Oct. 
  1913, 
  8 
  pp. 
  [Received 
  ISth 
  

   Sept. 
  1914.] 
  

  

  In 
  the 
  experiments 
  described 
  in 
  this 
  circular, 
  promising 
  results 
  in 
  the 
  

   destruction 
  of 
  aphids 
  were 
  obtained 
  and 
  there 
  is 
  reason 
  to 
  beheve 
  that 
  

   bhght 
  may 
  be 
  controlled, 
  to 
  some 
  extent, 
  by 
  the 
  same 
  means. 
  The 
  

   best 
  results 
  were 
  obtained 
  by 
  spraying 
  the 
  trees 
  while 
  in 
  a 
  dormant 
  

   condition, 
  or 
  just 
  after 
  the 
  first 
  growth 
  was 
  starting, 
  with 
  hme-sulphur 
  

   solution. 
  The 
  proportion 
  used 
  consisted 
  of 
  1 
  gallon 
  of 
  commercial 
  

   hme-sulphur 
  to 
  19 
  gallons 
  of 
  water. 
  Twenty-five 
  pounds 
  of 
  quick- 
  

   hme, 
  slaked 
  and 
  strained, 
  were 
  also 
  added 
  in 
  order 
  to 
  make 
  the 
  spray 
  

   more 
  visible 
  upon 
  the 
  trees. 
  The 
  problem 
  of 
  spraying 
  large 
  trees 
  

  

  