298 
Coccmella  L.  became  acclimated ; but  little  is  known  about  the  re- 
sults of  this  introduction. 
Howard,  who  made  a special  study  of  Hymenopterous  para- 
sites, called  attention  in  1880  to  the  ease  of  transporting  parasites 
of  Coccidae,  especially  during  winter  and  advised  the  introduc- 
tion of  Tomocera  calif ornica  from  the  Pacific  coast  to  the  eastern 
states  where  it  might  have  attacked  various  species  of  Lacnium. 
In  1883  the  Department  of  Agriculture 7 succeeded  in  intro- 
ducing pupae  of  Apanteles  glorneratus,  parasite  of  Pieris  rapae  and 
other  species  having  them  sent  from  England  by  G.  C.  Bignell 
of  Plymouth. 
These  parasites  were  distributed  in  various  localities  of  Co- 
lumbia, Iowa,  Nebraska,  Missouri  and  acclimated  there  splen- 
didly, spreading  everywhere. 
With  this  last* experiment  very  evident  proof  had  been  furnished 
of  the  possibility  of  acclimatizing  parasites  of  one  country  in  an- 
other and  it  had  been  possible  to  establish  also  their  efficacy,  but 
as  the  insect  in  question  was  a pest  of  vegetables  which  in  America 
already  had  other  parasites,  the  fact  was  only  considered  techni- 
cally by  entomologists.  There  occurred  also  another  experiment 
which  called  for  attention  by  its  perfect  result  and  by  the  value 
of  the  industry  it  saved  so  that  the  method  of  fighting  exotic 
insects  with  the  insects  that  destroy  them  in  their  original  home 
received  solemn  sanction  and  was  recognized  as  the  only  method 
to  be  always  followed  in  similar  cases  and  to  be  tried  in  others 
also. 
The  occasion  for  such  an  experiment  presented  itself  fortu- 
nately also  in  the  United  States  where  the  strong  will  to  act  is 
sustained  in  the  people  by  the  means  necessary  to  the  work.  The 
Insect  to  be  fought  was  iccrya  purchasi. 
leer  ay  purchasi , Mask. 
This  scalebug,  which  becomes  specially  dangerous  to  citrus 
fruit,  but  which  attacks  also  numerous  other  plants,  seems  to  have 
been  introduced  into  California  about  1868  and  probably  on 
.Acacia  latifolia. 
Hardly  had  this  Iccrya  and  the  rapidity  with  which  it  spread 
in  the  orange  groves  been  noticed  than  a general  alarm  was  felt 
among  California  orange  growers  and  all  possible  artificial  means 
to  fight  it  were  tried  but  in  vain.  It  continued  to  spread  not- 
withstanding all  the  measures  which  had  been  tried  without  con- 
sideration of  expense  and  soon  the  fruit  growers  became  discour- 
aged and  decided  to  cut  down  the  orange  and  lemon  trees  and  to 
substitute  other  industries.  Under  these  conditions  Riley,  as 
head  of  the  entomological  office  of  the  Department  of  Agricul- 
ture, considered  it  necessary  about  1884  to  establish  two  labora- 
7 Report  of  the  Entomologist  in  Rep.  U.  S.  Dept.  Agri.  for  1884,  p.  323 
