﻿466 
  L. 
  D. 
  CLE 
  ARE, 
  JR. 
  

  

  tin 
  being 
  slightly 
  tilted 
  to 
  allow 
  of 
  the 
  egress 
  of 
  any 
  caterpillars 
  that 
  hatch 
  within 
  

   the 
  tin. 
  Each 
  tin 
  is 
  placed 
  in 
  a 
  shallow 
  pan 
  containing 
  a 
  mixture 
  of 
  water 
  and 
  

   kerosene 
  or 
  molasses, 
  so 
  that 
  any 
  larvae 
  that 
  emerge 
  from 
  the 
  tins 
  will 
  crawl 
  into 
  

   the 
  liquid 
  and 
  be 
  destroyed. 
  It 
  is 
  advisable 
  to 
  have 
  a 
  few 
  holes 
  bored 
  about 
  the 
  

   bottom 
  of 
  the 
  tin 
  to 
  allow 
  of 
  a 
  circulation 
  of 
  air 
  and 
  so 
  avoid 
  over-dampness 
  and 
  the 
  

   growth 
  of 
  mould. 
  After 
  four 
  days 
  the 
  eggs 
  are 
  examined, 
  and 
  any 
  that 
  have 
  turned 
  

   black 
  are 
  kept 
  as 
  being 
  parasitised, 
  the 
  remainder 
  being 
  burnt, 
  and 
  the 
  tin 
  left 
  empty 
  

   to 
  receive 
  the 
  collection 
  of 
  the 
  same 
  day 
  of 
  the 
  following 
  week. 
  

  

  The 
  parasitised 
  clusters 
  are 
  then 
  placed 
  in 
  cigarette 
  or 
  other 
  small 
  tins, 
  and 
  

   returned 
  to 
  the 
  fields 
  from 
  which 
  they 
  were 
  collected. 
  The 
  tins 
  containing 
  parasitised 
  

   clusters 
  are 
  put 
  out 
  in 
  the 
  field 
  in 
  small 
  wooden 
  boxes, 
  eight 
  inches 
  square, 
  opened 
  

   at 
  one 
  side 
  and 
  hooked 
  upon 
  a 
  stake 
  about 
  four 
  feet 
  in 
  length 
  driven 
  into 
  the 
  ground 
  

   (PL 
  xxiv, 
  fig. 
  2). 
  The 
  open 
  side 
  of 
  the 
  box 
  should 
  be 
  away 
  from 
  the 
  prevailing 
  

   wind. 
  Parasitised 
  clusters 
  should 
  remain 
  in 
  the 
  field 
  about 
  five 
  days, 
  after 
  which 
  

   time 
  the 
  parasites 
  will 
  have 
  emerged 
  and 
  the 
  tins 
  can 
  be 
  used 
  for 
  fresh 
  supplies. 
  

  

  Collection 
  of 
  Parasitised 
  Clusters 
  before 
  Reaping. 
  

  

  It 
  can 
  be 
  readily 
  seen 
  that 
  the 
  method 
  of 
  burning 
  fields 
  previous 
  to 
  reaping, 
  

   which 
  is 
  in 
  general 
  practice, 
  must 
  destroy 
  a 
  large 
  number 
  of 
  insects 
  in 
  the 
  fields. 
  If 
  

   this 
  destruction 
  worked 
  equally 
  against 
  the 
  moth-borer 
  as 
  against 
  its 
  enemies 
  some- 
  

   thing 
  might 
  be 
  said 
  in 
  its 
  favour 
  from 
  this 
  point 
  of 
  view. 
  Unfortunately 
  the 
  very 
  

   opposite 
  is 
  the 
  case, 
  and 
  while 
  the 
  burning 
  destroys 
  a 
  very 
  large 
  number 
  of 
  parasites, 
  

   probably 
  the 
  majority 
  of 
  moth-borer 
  larvae 
  are 
  unaffected 
  by 
  it. 
  This 
  fact 
  is 
  amply 
  

   borne 
  out 
  by 
  the 
  number 
  of 
  larvae 
  found 
  in 
  the 
  tops 
  alone. 
  When 
  a 
  sufficient 
  supply 
  

   of 
  labour 
  is 
  available 
  this 
  waste 
  of 
  parasites 
  can 
  be 
  largely 
  avoided 
  by 
  sending 
  a 
  

   gang 
  through 
  the 
  fields, 
  previous 
  to 
  burning, 
  to 
  collect 
  the 
  black 
  parasitised 
  egg- 
  

   clusters. 
  These 
  clusters, 
  on 
  account 
  of 
  their 
  coloration, 
  are 
  easily 
  seen 
  on 
  the 
  leaves, 
  

   and 
  a 
  gang 
  working 
  conscientiously 
  will 
  bring 
  in 
  fair 
  numbers. 
  Care 
  must 
  be 
  taken 
  

   to 
  see 
  that 
  eggs 
  from 
  which 
  the 
  parasites 
  have 
  already 
  emerged 
  are 
  not 
  accepted, 
  

   for 
  unlike 
  those 
  from 
  which 
  the 
  larvae 
  have 
  emerged, 
  they 
  do 
  not 
  change 
  colour 
  

   after 
  this 
  has 
  occurred, 
  and 
  they 
  can 
  only 
  be 
  recognised 
  by 
  the 
  tiny 
  emergence 
  holes 
  

   made 
  by 
  the 
  parasites. 
  The 
  parasitised 
  clusters 
  obtained 
  in 
  this 
  way 
  are 
  sent 
  to 
  

   young 
  fields 
  in 
  which 
  the 
  parasitism 
  is 
  not 
  high, 
  and 
  in 
  such 
  fields 
  the 
  parasites 
  do 
  

   useful 
  work. 
  

  

  Parasitic 
  Enemies. 
  

  

  The 
  small 
  moth-borers 
  have 
  several 
  natural 
  enemies 
  in 
  British 
  Guiana, 
  and 
  there 
  

   is 
  not 
  the 
  slightest 
  doubt 
  that 
  they 
  serve 
  to 
  keep 
  the 
  pest 
  in 
  control 
  to 
  a 
  very 
  large 
  

   extent. 
  The 
  following 
  is 
  a 
  list 
  of 
  those 
  insects 
  known 
  to 
  be 
  parasitic 
  on 
  small 
  moth- 
  

   borers 
  in 
  this 
  colony 
  : 
  — 
  

  

  Egg 
  parasites 
  : 
  — 
  Trichogramma 
  minutum, 
  Riley, 
  and 
  Prophanurus 
  alecto, 
  Cwfd. 
  

  

  Larval 
  parasites 
  : 
  — 
  Iphiaulax 
  medianus, 
  Cam., 
  Iphiaulax 
  sp., 
  Cremnops 
  parvi- 
  

   fasciatus, 
  Cam., 
  Mesostenoideus 
  sp., 
  and 
  an 
  undetermined 
  species 
  of 
  Dexiid 
  fly. 
  

  

  Pupal 
  parasites 
  : 
  — 
  Heptasmicra 
  curvilineata, 
  Cam. 
  

  

  The 
  biological 
  control 
  of 
  small 
  moth-borers 
  appears 
  to 
  offer 
  many 
  possibilities 
  

   in 
  British 
  Guiana, 
  and 
  for 
  the 
  past 
  year 
  the 
  writer 
  has 
  been 
  engaged 
  on 
  this 
  work, 
  

   especially 
  in 
  connection 
  with 
  the 
  rearing 
  of 
  the 
  egg-parasites, 
  Trichogramma 
  minutum, 
  

   Riley, 
  and 
  Prophanurus 
  alecto, 
  Cwfd. 
  Although 
  the 
  work 
  has 
  been 
  in 
  operation 
  

   for 
  only 
  one 
  year 
  it 
  has 
  apparently 
  been 
  attended 
  with 
  favourable 
  results. 
  An 
  

   account 
  of 
  the 
  rearing 
  of 
  these 
  parasites 
  will 
  be 
  published 
  at 
  a 
  later 
  date. 
  

  

  Recommendations 
  for 
  the 
  Control 
  of 
  Moth-borers. 
  

  

  1 
  . 
  The 
  forking 
  of 
  both 
  banks 
  as 
  soon 
  as 
  the 
  tops 
  are 
  planted, 
  and 
  the 
  consequent 
  

   elimination 
  of 
  " 
  false 
  rows 
  " 
  or 
  old 
  banks. 
  

  

  