170 
JOUR^^AL  OF  HORTICULTURE  AND  COTTAGE  GARDEXER, 
Murcli  2,  1899. 
Eose  Pests. 
,  f 
Hoses  in  houses  wjiich  are  being  brought  on  steadily  by  the  aid  ot 
a  little  tire  heat  have  been  making  rapid  progress  during  the  last  few 
sunny  days.  Few  plants  show  the  beneficial  effects  of  welcome  sun¬ 
shine  after  a  spell  of  wet  cold  weather  quicker  than  do  Roses.  If 
such  weather  continue  thorough  syringings  should  be  given  daily, 
or  green'  aphides  will  soon  make  its  appearance.  Even  with  the  best 
of  attention  we  generally  get  a  slight  attack  duiing  the  spring  months ; 
but  if  fumigating  is  done  as  soon  as  the  first  signs  of  aphis  is 
noticed  there  is  not  much  difficulty  in  preventing  injury. 
Mildew  is,  perhaps,  the  worst  pest  we  have  to  contend  with  in 
the  Eose  house,  as  when  once  it  is  thoroughly  eradicated  it  frequently 
puts  in  an  appearance  again.  Finally,  ventilation  is  doubtless  in 
many  instances  the  primary  cause  of  such  attacks.  The  ventilators 
are,  perhaps,  kept  closed  for  days  together  while  the  weather  is  wet 
and  cold,  and  then  too  suddenly  thrown  open  when  bright  sunshine 
comes.  Provided  a  chink  of  air  is  given  early  on  bright  mornings  it 
■is  always  better  to  err  on  the  side  of  under,  rather  than  over-venti¬ 
lation.  Changeable  weather  such  as  we  generally  experience  in 
March  offers  so  many  temptations  to  put  air  on  too  freely;  the  sun 
may  be  thining  powerfully  while  a  cutting  wind  prevails.  Fear  of 
getting  some  of  the  shoots  scorched  then  induces  many  to  give  air 
too  freely,  and  if  the  shoots  near  the  ventilators  are  closely  watched 
signs  of  mildew  ma3’'  be  traced  a  day  or  two  alter.  The  time  when 
syringing  is  performed  is  also  a  matter  of  some  importance  during 
changeable  weather. 
It  is  often  a  practice  to  wait  until  the  house  is ;  closed  before 
syringing  is  performed.  This  is,  I  think,  a  mistake,  as  at  this  season 
dull  afternoons  often  succeed  bright  mornings  ;  and  in  the  case  of  late 
syringings  the  water  rests  upon  the  foliage  during  the  time  the 
temperature  of  the  house  is  rapidly  lowered.  The  plan  I  adopt  is  to 
syringe  while  the  sun  is  powerful,  whether  it  be  at  eleven,  twelve,  or 
one  o’clock,  the  ventilators  being  closed  when  the  sun  loses  powder. 
Another  fruitful  cause  of  mildew  in  the  cases  of  Roses  planted  out 
is  allowing  the  border  to  become  too  dry.  Such  borders  are  usually 
w’atered  W'hen  the  house  is  started,  and  if  the  soil  forming  the  border 
is  not  heavy,  by  the  time  the  first  buds  are  visible  it  wfill  generally 
require  another  application,  if  possible  of  liquid  manure,  or  as  a,  sub¬ 
stitute,  a  dressing  of  one  of  the  many  approved  chemical  manures, 
thoroughly  watered  in.  Such  timelj’-  attention  helps  to  put  substance 
into  both  leaves  and  flowers,  and  renders  them  more  proof  against 
insect  pests. 
A  cheap  wash  for  destroying  mildew  is  formed  by  dissolving  2  ozs. 
•of  softsoap  in  a  gallon  of  water,  and  adding  thereto  a  handful  of 
sulphur;  if  this  is  thoroughly  mixed  and  syringed  on  the  plant  it  will 
•kill  every  particle  of  mildew  that  it  touches.  There  is,  how-ever,  one 
slight  objection  to  its  use — viz.,  that  the  sulphur  adheres  to  the  leaves 
and  rather  spoils  their  appearance  for  a  time.  This  is  not  of  much 
■consequence  in  the  early  stages  of  growth,  but  when  the  wash  is 
applied  just  before  the  buds  begin  to.  open,  the  disfigured  leaves 
spoil  the  appearance  of  the  blooms,  and  when  hundreds  or  thousands 
are  ready  tor  cutting  at  one  time,  it  is  an  expensive  business  to  clean 
the  leaves.  Richard’.-^  Mildew  Insecticide  is  free  from  the  above 
drawback,  and  is  equally  effectual. — II.  D. 
Coloured  Ivy  Leaves.— Nothing  could  be  more  charming  than 
the  delicate  tints  of  the  common  Ivy  leaf  growing  on  walls  in  some  situations 
at  this  time  of  the  year.  I  fancy  it  must  be  the  condition  of  the  soil  that 
governs  the  colouration  of  leaves,  as  in  a  deep  fertile  medium  the  growth 
is  invariably  rank,  and  the  foliage  never  changes  ffora  its  dark  green  hue. 
I  know  of  an  establishment  built  of  sandstone,  the  walls  of  which  are 
partially  covered  with  Ivy.  With  the  exception  of  a  small  body  ot  soil 
in  which  the  Ivy  was  planted,  the  rooting  medium  is  chiefly  sandstone  and 
Tubble  left  near  the  foundations  at  the  time  of  building.  Consequent  upon 
this  the  growth  is  never  vigorous,  and  the  leaves  comparatively  small. 
During  the  winter  and  early  spring  the  latter  assume  a  variety  of  tints, 
which  are  both  charming  and  useful  for  decorative  purposes.  The  varied 
•colouring  resembles  very  much  the  ripening  tints  .of  Vine  leaves,  and  are 
generally  most  glowing  near  the  points  of  the  shoots.  Some  are  almost 
yellow,  others  a  reddish  brown,  and  others  again  nearly  crimson.  Sprays 
of  these  tinted  growths  detached  from  the  wallsin  lengths  are  very  pleasing 
for  decorations,  and  are  often  worn  bj^  ladies  in  preference  to  flowers. 
The  leaves  are  also  used  largely  in  the  make-up  of  wreaths,  crosses,  and 
other  floral  designs,  for  which  purpose  they  are  very  suitable.  I  know  of 
no  form  of  wreath  simpler  and  more  charming  than  one  made  up'  of  tinted 
Ivy  leaves,  with  the  flatness  broken  by  the  tip^  of  leading  shoots.  Also 
for  draping  round  pictures  and  ornaments  in  rooihs  sprays  of  coloured  Ivy 
are  elegant  and  effective. — H.  H.  '  ■  ' 
NYMPH^AS  AND  BEES. 
I  WAS  pleased  to  see  a  few  notes  on  the  above  in  the  Journal, 
page  378,  last  vol.,  by  Mr.  Hudson ;  and  although  he  does  not  at 
present  explain  the  question,  he  has  promised  to  make  observations 
during  the  coming  flowering  season,  and  I  have  no  doubt  that  the 
information  he  will  give  will  be  valuable  and  interesting. 
Your  contributor’s  remarks  re  the  flies  found  in  N.  stellata  is  also 
identical  with  mine,  and  further,  the  notes  given  in  a  recent  issue  as 
regards  bees  will  (as  far  as  my  observations  go)  also  apply  to  flies. 
N.  alba  is  visited  by  a  large  number  of  flies  thaL  are  about  the  size 
and  colour  of  the  common  honey  bee,  and  they  do  their  work  in  such 
a  thorough  manner  that  there  is  not  the  slighte>t  doubt  in  concluding 
that  they  are  the  principal  fertilising  agents.  This  fly  is  also  found 
dead  in  the  flowers.  Perhaps  one  or  two  may  be  found  in  every  . 
hundred  blooms. 
N.  stellata  flowers  contain  a  greater  number  of  dead  flies  with  me 
— about  fifteen  or  twenty  to  every  hundred  blooms.  Although  it  is 
about  the  length  of  an  ordinary  bee  the  body  is  smaller,  and  it  is 
nearl}^  black  in  colour,  and  is  quite  distinct  from  the  fly  that  is 
found  in  N.  alba. 
The  observations  I  have  made  have  caused  me  to  arrive  at  the 
following  conclusions: — The  freshly  developed  flowers  on  the  first  day 
of  opening  contain  a  watery  liquid  at  the  base,  which  is  surrounded  by 
a  well  arranged  circle  of  sepals.  The  second  or  third  day  of  opening 
the  sepals  are  irregular  and  more  tully  developed.  Flies  appear  to 
favour  the  second  or  third  day  flawers,  which  are  evidently  visited  with 
less  risk,  but  should  they  accidentally  or  otherwise  try  to  perform  their 
mission  on  the  fresh  blooms  they  invariably  get  their  bodies  wet  with 
the  watery  liquid.  I  have  often  seen  them  struggling  to  get  out, 
but  the  sepals  being  so  evenly  placed  they  can  only  take  hold  of  one 
or  two  each  time,  which  is  not  sufficient  to  support  them,  conse¬ 
quently  they  are  urempitated  again  into  the  liquid,  and  I  think  death 
is  caused  by  exhaustion,  assisted  no  doubt  by  the  odour  frem  the  fresh 
flowers. 
To  support  this  I  have  on  several  occasions  held  on  one  side  the 
flower  containing  the  struggling  fly,  which  has  enabled  it  to  crawl 
out,  and  after  a  few  seconds  it  has  taken  flight,  app.arently  none  the 
worse  for  its  bath.  I  have  never  yet  observed  a  fly  trapped  in  a  bloom 
on  the  second  or  third  day  of  opening. 
Referring  again  to  Nymphseas  and  bees  ;  an  article  (page  393) 
by  “Gardener  and  Bee-kee[)er,”  suggests  that  the  climate  may  play  an 
important  part  in  controlling  the  fertilising  agents.  I  do  not  hesitate 
in  arriving  at  the  same  conclusion,  for  although  the  bees  will  seek  for 
pollen  from  the  Nynphsea  flowers,  it  is  generally  during  the  first  two 
or  three  hours  thej'  are  open  in  the  morninLq  and  if  the  sun  is  by  that 
time  very  high,  most  of  them  disappear,  and  their  place  is  then  taken 
1)3'  the  flies  referred  to.  Bees  also  favour  the  second  or  third  day 
flower,  but  occasionally  they  will  visit  a  flower  on  the  first  day  or 
opening,  and  although  they  may  go  to  the  bottom  I  have  only  known 
a  lew  instances  where  they  have  been  trapped. 
My  present  theory  (which  is  based  to  some  extent  on  facts)  is  that 
bees,  or  other  fertilising  agents,  obtain  pollen  from  distinctive  species 
or  genera  that  may  contain  an  aroma  peculiarly  adapted  to  their  taste 
and  requirements,  and  allied  species  in  close  proximitj'’  are  yet 
refused  by  them  ;  it  seems  reasonable  to  suppose  that  by  artificially 
fertilising  the  two  species,  the  hybrids  obtained  would  in  all  proba¬ 
bility  contain  pollen  that  would  be  a  combination  of  the  two.  In  such 
cases  these  fertilising  agents  would  acquire  a  taste  for  the  hybrid, 
which  would  enable  them  to  visit  the  flowers  of  the  intermediate 
varieties,  and  also  the  original  species. 
As  regards  chance  hybrid  Nymphseas,  I  have  not  yet  seen  one 
obtained  from  naturally  fertilised  plants,  and  I  think  that  plants 
generally  retain  their  distinctive  types  and  colours  by  natural  fertilising 
agents.  When,  however,  the  natural  laws  are  broken  by  artificial 
crossing,  then  the  natural  agents  are  again  at  woik,  and  greater 
variations  produced  by  their  aid. 
About  eight  years  ago  a  friend  of  mine  had  a  very  large  and  beauti¬ 
fully  fringed  single  white  Hollyhock.  I  obtained  some  seeds  which 
I  saw  taken  from  the  plant.  I  sowed  it  early  in  spring  in  new  ground, 
where  native  shrubs  had  been  recently  taken  out.  There  must  have 
been  fully  100  seedlings,  but  very  few  had  the  Hollyhock  leaf.  Alter 
about  two  mouths  from  sowing  they  were  flowering.  The  flowers 
were  about  2^  inches  across;  some  were  white,  some  pink,  but  they 
were  a  distinct  cross  between  the  common  Mallow  and  the  Hollyhock. 
The  few  with  the  Hollyhock  leaf  remained  true  as  far  as  the  plant 
was  concerned,  and  flowered  the  following  season,  but  had  pale  yellow 
flowers  that  were  not  fringed  like  the  parent.  The  others  were 
annuals,  which  seeded  freely  and  came  up  in  the  same  place  for  two 
or  three  years  without  the  slightest  variation. — Thos.  Pockett, 
Malvern,  Australia: 
