333 
of  species  and  the  difficulty  of  distinguishing  them,  the  work  of 
men  who  dedicate  their  whole  lives  to  such  tasks. 
Some  entomologists  should  make  a study  of  general  biology  and 
others  should  be  given  charge  of  the  particulars  of  the  given  in- 
sect or  of  insects  harmful  to  a certain  industry  and  they  ^should 
be  located  in  field  laboratories  established  in  those  localities  which 
are  best  adapted  for  carrying  on  the  various  studies.  There 
should  be  at  least  one  entomologist  each  for  the  insects  of  olives, 
grape  vines,  fruit  trees,  forests,  citrus  fruit  and  cereals. 
These  entomologists  should  study  their  subject  exclusively  and 
be  directly  responsible  to  the  technical  director  at  the  head  of 
this  section,  so  that  they  could  not  digress  under  any  pretext.  It 
is  absolutely  necessary  that  each  entomologist  should  study  for 
many  years  one  or  two  insects  because  only  in  this  way  knowledge 
can  be  gained  about  the  most  minute  particulars  of  the  life  of  an 
injurious  insect  or  of  those  which  stand  in  relation  to  them  this 
being  indispensable  in  order  to  know  the  best  way  and  the  most 
opportune  for  initiating  the  artificial  or  natural  fight  against  an 
injurious  insect.  At  present  our  ignorance  even  about  the  biology 
of  the  most  common  insect  is  extreme  but  this  deplorable  condi- 
tion must  absolutely  cease  if  the  enormous  losses  which  our  na- 
tional economy  actually  suffers  through  the  work  of  so  many  in- 
sects are  to  be  reduced  to  some  extent. 
It  is  further  necessary  for  the  progress  of  agricultural  entomol- 
ogy that  good  laboratories  of  general  agricultural  entomology 
should  be  created  at  the  higher  schools  of  agriculture  which  would 
be  in  a position  to  function  as  entomological  district  stations.  One 
of  these  should  be  created  in  Puglia,  one  in  Sardinia  and  one  in 
Sicily. 
With  such  an  organization  of  agricultural  entomology  a new 
era  would  begin  in  Italy  in  the  fight  against  harmful  insects,  in 
which  beneficial  effects  would  not  be  slow  in  making  themselves 
felt  in  all  agriculture. 
What  do  the  United  States  teach  us  in  regard  to  insecticides? 
They  have  tried  many  of  them  and  have  recognized  as  the  best 
hydrocyanic  acid  gas,  arsenical  substances  and  the  mixture  of  sul- 
phur and  lime. 
Following  their  example  we  must  experiment  without  hesitation 
with  the  same  insecticides  against  the  same  insects  and  against 
insects  with  similar  habits  if  economically  convenient.  There  is 
no  reason  for  casting  aside  the  first  two  because  they  are  very 
poisonous  and  the  third  one  because  it  requires  a little  time  for 
preparation.  The  gases  of  cvanide  acid  used  with  the  necessary 
precaution  are  harmless  and  the  same  may  be  said  of  the  arsenical 
substances,  while  their  efficiency  in  destroying  insects  is  certain. 
The  sulphur  and  lime  mixture  is  a very  good  insecticide  and  has 
the  additional  advantage  of  substituting  in  many  cases  petroleum 
and  tar-oil,  which  are  more  expensive  (and  specially  the  former, 
even  the  imported)  and  of  increasing  the  consumption  of  sul- 
phur of  which  our  industry  is  much  in  need. 
