﻿388 
  Transactions. 
  — 
  Zoology, 
  

  

  The 
  chief 
  difficulty 
  under 
  which 
  I 
  have 
  laboured 
  has 
  been 
  that 
  of 
  being 
  

   unable 
  to 
  compare 
  my 
  specimens 
  of 
  New 
  Zealand 
  scale-insects 
  with 
  those 
  

   of 
  other 
  countries. 
  The 
  work 
  just 
  mentioned 
  has, 
  therefore, 
  come 
  most 
  

   opportunely 
  to 
  me 
  as 
  a 
  text-book. 
  

  

  Not 
  professing 
  any 
  degree 
  of 
  entomological 
  science, 
  I 
  may, 
  perhaps, 
  in 
  

   my 
  descriptions 
  of 
  these 
  insects, 
  fail 
  sometimes 
  in 
  properly 
  expressing 
  

   myself. 
  I 
  must 
  take 
  my 
  chance 
  of 
  this, 
  declaring 
  myself 
  quite 
  open 
  to 
  

   correction. 
  

  

  The 
  Coccidse 
  are, 
  as 
  I 
  said, 
  a 
  family 
  of 
  insects 
  of 
  the 
  order 
  Homoptera. 
  

   The 
  chief 
  distinguishing 
  features 
  dividing 
  them 
  from 
  all 
  the 
  other 
  families 
  

   are, 
  1st, 
  the 
  absence 
  of 
  wings 
  or 
  elytra 
  in 
  the 
  females, 
  and, 
  2ud, 
  the 
  absence 
  

   of 
  a 
  mouth 
  or 
  rostrum 
  in 
  the 
  males. 
  

  

  The 
  damage 
  done 
  by 
  these 
  insects, 
  which 
  attach 
  themselves 
  to 
  different 
  

   trees, 
  is 
  very 
  great. 
  Everybody 
  must 
  know 
  the 
  scale 
  on 
  the 
  apple 
  and 
  pear 
  

   trees, 
  which 
  covers 
  the 
  trunk 
  and 
  branches 
  and 
  eventually 
  kills 
  the 
  tree. 
  

   Every 
  gardener 
  knows 
  how 
  destructive 
  they 
  are 
  to 
  his 
  flowers 
  and 
  choice 
  

   plants, 
  whether 
  in 
  the 
  o|)en 
  air 
  or 
  in 
  green-houses. 
  It 
  is 
  stated 
  that, 
  in 
  

   France, 
  different 
  species 
  of 
  Coccus 
  and 
  Lecaniiim 
  have 
  destroyed 
  whole 
  

   forests 
  of 
  almond, 
  orange, 
  and 
  olive 
  trees 
  ; 
  in 
  Mauritius 
  and 
  in 
  Brazil 
  the 
  

   sugar-cane, 
  and 
  in 
  Ceylon 
  the 
  coffee-plant, 
  has 
  been 
  ravaged 
  by 
  them. 
  Sir 
  

   Wyville 
  Thomson, 
  in 
  the 
  volumes 
  just 
  published 
  of 
  the 
  voyage 
  of 
  the 
  

   "Challenger," 
  states 
  that 
  in 
  the 
  Azores 
  the 
  cultivation 
  of 
  oranges 
  was 
  for 
  a 
  

   time 
  almost 
  stopped 
  by 
  a 
  small 
  species 
  of 
  Coccus 
  ; 
  and 
  we 
  all 
  know 
  how 
  the 
  

   oranges 
  and 
  lemons 
  which 
  come 
  to 
  us 
  from 
  Sydney 
  are 
  covered 
  with 
  

   innumerable 
  insects 
  of 
  the 
  same 
  family. 
  In 
  Christchurch 
  a 
  good 
  example 
  

   of 
  their 
  work 
  may 
  be 
  seen 
  in 
  the 
  holly 
  hedge 
  round 
  the 
  Christchurch 
  Club, 
  

   where 
  Lecaniuin 
  hespendum. 
  reduced 
  the 
  plants 
  a 
  few 
  years 
  ago 
  to 
  a 
  miser- 
  

   able 
  state. 
  In 
  Auckland, 
  I 
  saw 
  a 
  month 
  or 
  two 
  ago 
  a 
  fine 
  hedge 
  of 
  the 
  

   kangaroo 
  Acacia 
  being 
  rapidly 
  destroyed 
  by 
  colonies 
  of 
  an 
  insect 
  which 
  

   appears 
  to 
  be 
  a 
  new 
  species 
  of 
  Coccus, 
  allied 
  to 
  Icenja. 
  

  

  There 
  is 
  an 
  immense 
  variety 
  in 
  the 
  appearance 
  of 
  the 
  different 
  species 
  

   of 
  Coccidse, 
  and 
  this 
  variety 
  is 
  rendered 
  still 
  greater 
  by 
  the 
  fact 
  that 
  the 
  

   insects 
  themselves 
  are 
  by 
  no 
  means 
  the 
  same 
  as 
  a 
  rule 
  in 
  all 
  the 
  stages 
  of 
  

   their 
  existence," 
  and 
  by 
  the 
  difference 
  between 
  the 
  sexes. 
  There 
  are, 
  how- 
  

   ever, 
  certain 
  characters 
  which 
  belong 
  to 
  all 
  the 
  species, 
  and 
  with 
  which 
  I 
  

   may 
  fitly 
  begin 
  my 
  description 
  of 
  those 
  that 
  I 
  have 
  observed 
  : 
  — 
  

  

  1st. 
  In 
  the 
  first 
  stage, 
  after 
  leaving 
  the 
  qqq, 
  there 
  is 
  no 
  appreciable 
  

   difference 
  between 
  the 
  male 
  and 
  the 
  female. 
  The 
  change 
  in 
  form 
  does 
  not 
  

   take 
  place 
  until 
  the 
  insect 
  discards 
  its 
  second 
  pellicle. 
  

  

  2nd. 
  The 
  males 
  of 
  all 
  species 
  have 
  two 
  wings, 
  six 
  legs, 
  two 
  antennae 
  

   (generally 
  pretty 
  long), 
  two 
  proper 
  eyes, 
  and 
  in 
  some 
  species 
  two 
  other 
  eyes 
  

   placed 
  further 
  back 
  on 
  the 
  head. 
  

  

  