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the  year  1897,  he  was  compelled  to  consider  the  results  obtained  in 
America  and  Portugal  in  fighting  this  scalebug  with  a predatory 
insect. 
In  1900,  in  the  preface  to  his  “Insects  Noxious  to  Fruit-trees 
and  Grape-vine”  he  recognized  the  importance  of  insect  parasites 
and  recommended  the  greatest  regard  for  them  in  the  use  of  in- 
secticides against  injurious  insects.  He  condemned  winter-cures 
in  the  majority  of  cases,  saying  that  they  should  he  limited  to  the 
destruction  of  those  stages  which  do  not  harbor  parasites. 
In  1901  he  read  before  the  congress  of  the  Zoological  Union 
at  Naples  a paper  under  the  title  “The  Advantages  which  Agri- 
culture may  Expect  from  the  Work  of  Insectivorous  Birds,” 
setting  forth  reasons  rather  in  favor  of  entomophagous  insects 
and  against  birds  as  sustained  by  Rondani,  Ghiliani  and  others. 
In  1902  he  wrote  several  articles  on  the  natural  methods  of  fight- 
ing insects  still  recommending  that  in  fighting  them  with  insecti- 
cides regard  should  be  had  for  their  parasites  and  proposed, 
against  Conchylis,  to  collect  its  larvae  and  chrysalides  and  place 
them  in  small  boxes  having  on  their  covers  a large  opening  pro- 
tected by  wire  netting  of  1 mm.  mesh  so  as  to  permit  the  escape 
of  parasites  and  not  of  the  adults. 
He  announced  this  method  of  fighting  as  new,  but,  as  we  have 
seen,  it  had  already  been  suggested  along  the  same  lines  by  Com- 
stock for  Pieris  rapae  and  in  a similar -manner  by  Riley  (1870) 
and  by  Decaux  (1872-1889)  for  other  insects. 
I myself  recommended  the  use  of  small  boxes  with  wire  netting 
in  order  to  leave  the  way  open  for  parasites,  to  fight  Dacus  oleae, 
Prays  oleellus,  Asphondylia  lupini,  and  with  Martelli,  I pointed 
out  a natural  method  against  Ceroplastes  rusci.  Besides,  in  my 
lectures  on  agricultural  entomology  I recommended  a natural 
method  of  fighting  Pieris,  Aporia,  Lymantria,  Euproctis,  Plusia, 
Maiacosoma  (also  for  their  eggs),  Carpocapsa,  Conchylis  and 
Eudemys,  Fabrus , and  many  other  insects. 
To  fight  Dacus  oleae  I recommended  also  to  cultivate  in  the 
olive-groves  various  plants  on  which  live  insects  parasitised  by 
the  ectophagi  of  Dacus. 
In  the  United  States  one  of  the  gravest  entomological  problems 
is  really  the  fight  of  Anthonomus  grandis  Boh.  Not  having  suc- 
ceeded there  in  finding  the  parasite  peculiar  tO'  Anthonomus,  they 
tried  to  check  its  damage  by  cultural  methods  and  having  further 
established  that  the  parasites  of  other  Curculionids  now  attack 
also  Anthonomus  they  contemplate  increasing  the  number  of  such 
parasites  by  planting  in  the  cotton  fields  or  around  them  other 
plants  which  are  attacked  by  insects  whose  parasites  have  adapted 
themselves  also  to  Anthonomus  grandis. 
Besides  drawing  profit  from  parasites  of  a given  species  in  one 
and  the  same  locality  experiments  have  been  made  with  parasitic 
insects  transported  from  one  place  to  another  of  the  same  region 
