296 
and  also  from  one  region  to  another  of  the  same  continent  and 
from  one  continent  to  another. 
1 1.— Advices  to  Utilize  Insects  Parasitic  on  Insect  Pests  by 
Transporting  them  from  One  Locality  to  Another  of  the  Same 
Region. 
Riley  5 seems  to  have  been  also  the  first  to  distribute  parasites 
of  a certain  species  from  one  locality  to  another  of  the  same 
region.  He  did  this  with  parasites  of  Conotrachelus  nennrphar 
Hbst.  ( Sigalphus  curculionis  Fitch  and  Porizon  conofracheli 
Riley)  sending  them  from  Kirkwood,  Mo.,  to  other  parts  of  the 
same  state.  He  made  the  same  suggestion  also  for  several  para- 
sites of  Coccids. 
Le  Baron  also  (1871-1872)  transported  little  branches  covered 
with  scalebugs  of  apple  trees  infested  by  Aphelinus  mytilaspidis 
from  one  locality  in  Illinois  to  another  (from  Geneva  to  Galena) 
with  good  results. 
In  such  cases,  as  is  mentioned  also  by  Riley,  it  had  not  been  first 
determined  whether  in  the  new  localities  into  which  parasites  had 
been  transported,  these  existed  already  or  not,  I would  rather  add 
that  it  is  almost  certain  that  they  were  there  already  and  I insist 
that  a method  by  which  it  is  intended  to  transport  parasites  in 
the  same  region  from  one  locality,  where  the  harmful  insects  are 
much  infested  to  another  one  where  the  same  insects  are  hardly 
infected,  is  to  be  recomjnended  when  economy  and  other  cir- 
cumstances permit  of  it. 
Decaux  made  in  France  several  experiments  in  transporting 
parasites  from  one  place  to  another,  among  them  Tillus  formi- 
carius  Oliv.  He  collected  a certain  number  of  specimens  of  this 
insect  living  at  the  expense  of  xylophagous  insects,  in  the  first 
part  of  April  and  brought  them  to  the  pines  at  Cayeux,  a distance 
of  200  kilometers,  where  they  developed  rapidly,  their  larvae  de- 
stroying those  of  the  Coleopteron  Blastophagus  piniperda  F. 
which  had  increased  in  that  locality  to  an  alarming  degree. 
He  operated  in  an  analogous  manner  to  combat  Phloeosinus 
thuyae  Perris  and  Ph.  Bicolor  injurious  to  the  Thuya  planta- 
tions of  the  nurseries  of  Paris. 
I have  recommended  the  transportation  of  larvae  of  Prays 
parasitised  by  Argeniaspis  to  a locality  where  this  parasite  is  very 
scarce  because  by  this  operation  one  would  certainly  succeed  in  re- 
establishing the  equilibrium  in  a lesser  number  of  generations 
than  would  be  required  if  all  were  left  to  natural  local  conditions. 
In  the  United  States  in  1907  a similar  experiment  was  carried 
out  by  Professor  Webster  with  Polygnotus,  parasite  of  Mayetiola 
destructor  Say.  He  had  on  the  8th  of  April  many  puparia  of 
this  Cecidomyid,  90%  of  them  parasitised  by  Polygnotus,  trans- 
ported from  Marvon,  Pa.,  to  Sharpsburg,  Md.,  where  the  parasite 
6 Third  Report,  Insects,  of  Missouri,  1870,  page  29,  and  Fifth  Report, 
3873,  page  90. 
