February  6,  1902. 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
127 
to  contend  against  at  the  present  time  are  all  imported  forms. 
Of  the  numerous  forms  of  indigenous  ones  that  are  to  be  found 
there,  none  are  ever  likely  to  become  pests,  all  being  so  heavily 
parasitised  or  fed  upon  by  predaceous  forms,  that  it  is  difficult 
to  secure  healthy  specimens  of  some  species,  and  especially  the 
scale  insects.  But  transplant  a  single  femjule  specimen  or  two 
to  a  new  region,  and  place  it  upon  the  same  form  of  food  plant, 
of  Eucalyptus  trees  growing  no  insects  have  ever  attacked  them, 
excepting  the  white  scale  (Iceiya  Purchasi),  that  country  having 
secured  its  Eucalyptus  trees  all  from  Australia,  but  by  seed,  and 
that  prevented  their  insects’  enemies  from  being  introduced ; 
but  when  the  white  scale  was  introduced  into  California  upon 
some  young  Citrus  trees  from  Australia,  it  soon  attacked  the 
Eucalyptus,  as  well  as  all  other  forms  of  vegetation,  the  same 
NEPENTHES  NORTHIANA.  (See  note-'on: page:  128.) 
it  will  soon  become  a  pest.  That  is  what  some  entomologists 
claim  is  produced  by  climatic  changes ;  but  take  the  same  insects 
and  place  them  upon  a  clean  plant  of  the  same  species  in  Western 
Australia,  and  protect  them  from  their  natural  enemies,  and  it 
will  soon  be  covered  with  the  insects. 
In  Australia  there  are  a  large  number  of  insects  of  various 
forms  attack  and  live  upon  the  various  species  of  Eucalyptus  trees, 
while  in  California,  U.S.A.,  where  there  are  thousands  of  acres 
as  it  does  in  Australia,  but  there  it  never  beoom^  noticeable, 
owing  to  its  natural  checks.  A  very^  good  illustration  upon  this 
subject  may  be  found  in  a  recent  publication,  by  Mr.  E.  E.  Green, 
on  the  insects  of  Ceylon,  in  which  he  says  all  troublesome  insecta 
of  that  island  are  introduced  species.  Out  of  twenty-six  species 
of  Chionaspis  found  there  only  three  are  injurious,  and  these 
three  are  imported  forms. — (Geo.  Compere,  in  “Journal  of  the 
Department  of  Agriculture  of  Western  Australia.”) 
