246  Experiments  with  Pyre  thrum  Roseum.  {^M°yrt'J^rm" 
depend  on  the  quality  of  the  material  used,  but  after  the  experiments 
we  have  tried,  we  feel  confident  that  with  good  Dalmatian  powder 
there  need  be  no  failure.  It  will  be  interesting  to  learn  as  opportunity 
offers  how  moths  and  other  insects  will  be  affected  by  the  use  of  insect 
powders.  If  the  beautiful  specimens  which  sometimes  fly  into  our 
rooms  at  night  can  be  drugged  in  this  way  and  captured  without  a 
struggle,  we  may  add  many  a  perfect  specimen  to  our  collections  which 
would  otherwise  be  more  or  less  defaced.  There  is  quite  a  field  for 
experiment  here. 
EXPERIMENTS   WITH    PYRETHREUM   ROSEUM  IN 
KILLING  INSETCS. 
By  W.  L.  Carpenter,  U.S.A. 
In  the  August  number  of  the  "American  Naturalist "  appeared  an  arti- 
cle on  the  carpet-beetle,  by  J.  A.  Lintner,  in  which  the  statement  was 
made,  as  nearly  as  I  can  now  remember,  that  "  although  he  had  never 
used  Pyrethreum  roseum  as  an  insect  exterminator,  he  had  no  doubt 
that  it  would  prove  unavailing  if  applied  to  the  destruction  of  the 
Antlirenusy  As  it  seemed  unfair  to  condemn  without  a  trial  what  is 
generally  regarded  as  a  useful  insect  poison,  I  resolved  to  test  it  experi- 
mentally, and  now  present  the  result  of  several  trials  with  different 
orders  of  insects. 
The  insects  were  placed  under  a  tumbler,  which  was  slightly  raised 
to  admit  fresh  air,  and  a  small  quantity  of  the  Pyrethreum  roseum,  or 
Persian  Insect  Powder  of  commerce,  introduced  on  the  point  of  a  pen- 
knife. The  movements  of  the  insects  brought  them  in  contact  with 
the  powder,  which  readily  adhered  to  the  body ;  in  attempting  to 
remove  it  from  their  appendages,  a  few  particles  would  be  carried  to  the 
mouth  and  thus  incorporated  in  the  juices  of  the  stomach  with  fatal 
effect. 
A  honey-bee  became  perfectly  helpless  in  fifteen  minutes,  a  mud- 
wasp  in  eight  minutes,  a  small  species  of  ant  in  five  minutes  ;  a  small 
species  of  Pyralidce  became  helpless  in  twenty  minutes  ;  the  large 
Papilio  asterias  resisted  the  effects  of  the  drug  for  over  one  hour,  and  on- 
being  released  seemed  to  recover,  but  died  next  day.  A  larva  of  one 
of  the  Noctucelita:  did  not  seem  susceptible  ;  its  jaws  were  repeatedly 
filled  with  the  powder,  which  it  invariably  ejected  by  throwing  out  its 
juices  ;   at  the  end  of  two  hours  it  was  still  able  to  crawl  feebly.  A. 
