294 
The  same  Riley  recommended  treatment  also  for  Thyridopteryx 
cphemeraeforniis  Haw.  and  Prof.  J.  H.  Comstock  advised  to 
place  the  chrysalides  of  Pieris  rapae,  gathered  by  hand,  in  boxes 
covered  with  wire  netting  so  as  to  permit  an  easy  exit  to  their 
parasite,  Pteromalus  puparum,  and  to  impede  that  of  the  butter- 
flies that  develop  from  healthy  chrysalides. 
As  the  principle  has  thus  been  clearly  established  and  on  it 
advices  were  based  for  a fight  which  had  the  end  in  view  to  kill 
the  harmful  insects  and  save  their  parasites  it  was  and  still  is 
possible  to  recommend  for  each  case  appropriate  methods  besides 
those  already  described. 
Decaux  in  France  from  1872-1889  showed  himself  greatly  in 
favor  of  such  a method  and  recommended  repeatedly  to  collect 
the  injurious  insects,  keep  them  in  laboratories  located  in  the  gar- 
dens (or  in  other  places  where  there  are  plants  to  be  defended) 
and  to  place  them  in  vessels  covered  with  gauze.  The  agricultur- 
ists should  visit  such  laboratories  daily  and  set  free  the  entomo- 
phagous  insects  killing  on  the  other  hand  the  adults  of  the  pests. 
He  recommended  the  protection  of  the  predators  as  well  as  the 
endophagi  and  ectophagi  and  in  order  to  educate  the  agricultural 
public,  he  proposed  that  biological  collections  should  be  made  and 
memoranda  published  on  the  habits  of  injurious  insects  and  their 
parasites. 
So  we  see  that  Decaux  had  devised  a complete  organic  plan 
for  a rational  natural  fight  against  noxious  insects,  a plan  which 
we  recommend  fundamentally  even  today.  Notwithstanding  the 
example  of  the  glorious  period  of  Rondani  the  agricultural  ento- 
mologist of  Italy  up  to  1900  neglected  almost  entirely  the  biology 
of  harmful  insects  and  their  parasites  and  never  thought  of  na- 
tural methods  of  battle.  In  1892  we  hear  the  first  voice  in  sincere 
protest  against  the  way  things  were  going  in  agricultural  ento- 
mology in  our  country,  raised  by  Dr.  Ginseppe  Jatta  who,  having 
been  for  several  years  professor  of  agricultural  entomology  at 
Portici,  had  occasion  to  notice  how  limited  and  uncertain  was  the 
knowledge  of  noxious  insects  and  how  much  less  that  of  fighting 
methods,  all  of  which  were  recommended  on  a basis  of  insecti- 
cides and  by  somebody  with  relative  speculations 
scientific. 
Targioni,  who  was  for  many  years  director  of  the  royal  sta- 
tion of  agricultural  entomology  at  Florence,  did  almost  exclusive- 
ly systematic  and  insecticide  work  as  did  also  his  assistants,  A. 
Berlese  (1886-90)  and  G.  Del  Guercio,  although  about  1900  the 
latter  made  the  attempt  to  take  up  also  biology.  Berlese  be- 
came in  1890  professor  of  general  and  agricultural  zoology  at 
Portici  and  for  many  years,  as  director  of  the  entomological 
laboratory,  recommended  principally  the  use  of  insecticides  two 
of  which  were  proposed  by  himself,  without  thinking  of  natural 
methods  of  control  until  in  1900,  finding  himself  in  the  grip  of 
Iceryct  purchasi  Mask.,  which  he  had  raised  in  a hothouse  during 
