﻿IDENTIFICATION 
  OF 
  ANOPHELINAE 
  AND 
  THEIR 
  LARVAE. 
  331 
  

  

  springing 
  from 
  a 
  chitinons 
  pocket 
  near 
  the 
  middle 
  of 
  the 
  thorax 
  are 
  easily 
  recog- 
  

   nisable 
  (fig. 
  1, 
  a). 
  This 
  characteristic 
  alone 
  suffices 
  to 
  distinguish 
  the 
  larvae 
  of 
  

   A. 
  funestus 
  from 
  those 
  of 
  the 
  other 
  island 
  species. 
  It 
  must 
  be 
  remembered 
  that 
  the 
  

   larvae 
  of 
  A. 
  costalis 
  carry 
  the 
  same 
  hairs, 
  but 
  these 
  are 
  not 
  nearly 
  so 
  conspicuous 
  

   and 
  are 
  difficult 
  to 
  detect 
  even 
  with 
  a 
  lens. 
  The 
  palmate 
  hairs 
  are 
  better 
  defined 
  

   i;han 
  those 
  of 
  A. 
  costalis. 
  

  

  Anopheles 
  maurifianus, 
  Grp. 
  

  

  The 
  larvae 
  are 
  easily 
  identified 
  ; 
  the 
  antennae 
  carry 
  a 
  conspicuous 
  hair-tuft 
  in 
  

   the 
  median 
  region 
  and 
  there 
  are 
  two 
  very 
  characteristic 
  fan-shaped 
  tufts 
  of 
  short 
  

   black 
  hairs 
  above 
  the 
  mouth-brushes. 
  These 
  two 
  characters 
  are 
  sufficient 
  for 
  the 
  

   identification 
  of 
  these 
  larvae. 
  The 
  abdomen 
  in 
  both 
  old 
  and 
  young 
  larvae 
  is 
  

   marked 
  with 
  whitish 
  bands. 
  The 
  living 
  larvae 
  have 
  the 
  peculiar 
  habit 
  of 
  twisting 
  

   themselves 
  into 
  an 
  S-shape, 
  a 
  habit 
  which 
  I 
  have 
  not 
  noticed 
  in 
  any 
  other 
  Anopheline 
  

   larva. 
  

  

  Anopheles 
  squamosus, 
  Theo. 
  

   The 
  larvae 
  of 
  this 
  Anopheline 
  are 
  unknown 
  to 
  me. 
  

  

  Technique 
  and 
  Methods 
  of 
  Control. 
  

  

  A 
  simple 
  method 
  of 
  examining 
  mosquito 
  larvae 
  is 
  to 
  remove 
  one 
  from 
  the 
  glass 
  

   collecting 
  jar 
  by 
  means 
  of 
  a 
  pipette, 
  place 
  it 
  in 
  a 
  drop 
  of 
  clean 
  water 
  on 
  a 
  microscope 
  

   slide, 
  and 
  anaesthetise 
  it 
  by 
  placing 
  near 
  it 
  a 
  pledget 
  of 
  cotton- 
  wool 
  soaked 
  in 
  chloro- 
  

   form 
  covering 
  all 
  with 
  an 
  inverted 
  petri 
  dish 
  for 
  a 
  few 
  minutes. 
  The 
  larva 
  can 
  then 
  

   be 
  moved 
  about 
  and 
  turned 
  by 
  means 
  of 
  a 
  fine 
  dissecting 
  needle 
  with 
  a 
  minimum 
  of 
  

   injury 
  to 
  its 
  finer 
  hairy 
  structures. 
  

  

  The 
  Public 
  Health 
  Officer 
  will 
  be 
  greatly 
  aided 
  in 
  his 
  work 
  by 
  a 
  mosquito 
  brigade 
  

   of 
  native 
  boys 
  trained 
  to 
  recognise 
  the 
  larvae 
  of 
  the 
  three 
  genera 
  Anopheles, 
  Culex 
  

   and 
  Stegomyia. 
  We 
  supply 
  our 
  mosquito 
  brigade 
  with 
  glass 
  jars 
  for 
  collecting 
  

   larvae 
  and 
  with 
  long-handled 
  white 
  enamelled 
  iron 
  ladles, 
  which 
  make 
  most 
  efficient 
  

   dippers 
  and 
  in 
  which 
  the 
  most 
  minute 
  larvae 
  are 
  easily 
  seen 
  against 
  the 
  white 
  back- 
  

   ground. 
  

  

  A 
  further 
  valuable 
  means 
  of 
  indicating 
  the 
  presence 
  of 
  mosquitos 
  and 
  of 
  obtaining 
  

   specimens 
  of 
  larvae 
  is 
  the 
  use 
  of 
  mosquito 
  traps. 
  The 
  traps 
  used 
  are 
  ordinary 
  

   wooden 
  tubs 
  about 
  2J 
  feet 
  in 
  diameter 
  cut 
  down 
  to 
  a 
  height 
  of 
  6 
  inches. 
  These 
  

   are 
  sunk 
  till 
  their 
  rims 
  are 
  flush 
  with 
  the 
  ground, 
  soil 
  to 
  the 
  depth 
  of 
  some 
  2 
  inches 
  

   is 
  spread 
  in 
  them, 
  water 
  is 
  poured 
  on 
  to 
  the 
  requisite 
  depth 
  and 
  finally 
  some 
  aquatic 
  

   weeds 
  are 
  floated 
  on 
  the 
  surface. 
  These 
  traps, 
  under 
  the 
  control 
  of 
  the 
  mosquito 
  

   brigade, 
  are 
  placed 
  at 
  intervals 
  round 
  the 
  periphery 
  of 
  the 
  town. 
  

  

  The 
  traps 
  are 
  examined 
  every 
  six 
  days 
  for 
  the 
  presence 
  of 
  larvae, 
  all 
  species 
  being 
  

   recorded. 
  The 
  method 
  of 
  examining 
  the 
  traps 
  is 
  as 
  follows. 
  Each 
  trap 
  is 
  visited 
  

   by 
  an 
  inspector 
  on 
  the 
  sixth 
  day, 
  and 
  its 
  whole 
  contents 
  after 
  agitation, 
  are 
  emptied 
  

   into 
  a 
  bucket 
  bearing 
  the 
  same 
  number 
  as 
  the 
  trap. 
  The 
  buckets 
  are 
  brought 
  to 
  

   the 
  Health 
  Office 
  for 
  critical 
  examination. 
  The 
  contents 
  of 
  the 
  buckets 
  are 
  

   strained 
  through 
  fine 
  muslin, 
  the 
  residue 
  and 
  debris 
  left 
  adhering 
  to 
  the 
  muslin 
  

   being 
  washed 
  down 
  into 
  a 
  large 
  white 
  enamelled 
  dish, 
  in 
  which 
  the 
  larvae 
  can 
  easily 
  

  

  