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most  free,  as  I myself  could  observe.  From  China  and  Japan  Koe- 
bele  introduced  to  Hawaii  another  coccinellid  ( Sticolotis  punctata) 
predatory  on  Dactylopius.  In  Hawaii  there  is  now  Pseudococcus 
(Dactylo pins)  nipae,  Mask.,  widely  distributed  on  various  plants, 
because  it  is  only  seldom  attacked  by  Cryptolaemu*s  and  only  in 
winter  by  Rhizobius  ventralis. 
Several  parasites  collected  by  Koebele  in  Mexico  seem  not  to 
have  become  acclimated. 
In  Mexico,  near  Jalapa,  I too  have  seen  Pseudococcus  nipae  ac- 
tively attacked  by  Hyperaspis  sylvestrii,  Weise.,  and  by  a fungus 
and  it  is  necessary  now  that  these  enemies  should  be  introduced  to 
Hawaii. 
Pidvinaria  psidii  has  been  very  harmful  in  Hawaii,  since  Koe- 
bele after  a visit  to  the  coffee  plantations  in  1894,  wrote  that  he 
had  never  seen  trees  blackened  so  much  by  smut,  which  had  de- 
veloped on  the  sugary  excreta  secreted  by  Pidvinaria , while  three 
years  later  he  found  the  same  locality  almost  freed  by  Cryptolae - 
mils  which  had  attacked  Pidvinaria,  destroying  its  eggs.  Also 
the  chalcidids,  Microterys  Uavus,  How.,  and  another  not  deter- 
mined species,  destroy  this  Pidvinaria. 
Pidvinaria  mammeac  is  also  attacked  in  Hawaii  by  Cryptolae- 
mus  by  Novius  cardinalis  and  by  Hyperaspis. 
Finally  Cryptolaemus  has  proved  a most  efficacious  predator 
and,  in  Hawaii,  as  useful  (if  not,  as  some  say,  more  so)  than 
Novius  cardinalis. 
I have  taken  living  Cryptolaemus  from  Hawaii  and  from  Cali- 
fornia and  have  distributed  them  at  Capri,  Ischia,  Palermo,  Por- 
tici,  in  citrus  orchards  infected  by  Dactylopius  citri  which,  al- 
though it  has  a number  of  parasites  in  our  country,  frequently  be- 
comes very  harmful. 
CEROPLASTES  RUBENS,  MASK. 
This  species  of  Asiatic  origin  was  up  to  about  1895  very  com- 
mon in  Hawaii,  but  Koebele  succeeded  in  finding 'in  China  and 
sending  to  Honolulu  various  hymenopterous  parasites  of  which 
at  least  four  have  become  acclimated. 
In  1900  Ceroplastes  rubens  had  become  rare.  Among  the  most 
efficacious  hymenoptera  there  we  have  to  add  Tomocera  cero- 
plastes and  an  Encirtid. 
DIASPINAE. 
The  numerous  scalebugs  of  this  group  are  very  harmful  and 
are  amongst  the  most  difficult  to  fight  with  natural  means,  in  fact 
while  against  Icerya,  Lecanti  and  Dactylopini  very  good  or  good 
results  have  been  obtained,  against  Diaspini  the  results  have  been 
only  partial,  so  that  in  California,  at  least,  for  the  present,  agri- 
culturists prefer  to  fight  the  scalebugs  with  cyanide  acid  fumiga- 
