JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
August  1,  1901. 
98 
command,  ihe  night  temperature  will  read  lar  too  low  for  the  tropical 
kinds.  For  the  Odontoglossums  and  Masdevallias  nothing,  of  course, 
could  be  better,  as  the  bouses  may  be  left  open  day  and  night,  the 
plants  revelling  in  the  cool  moist  air.  The  least  warmth  in  the  pipes  is 
sufficient  in  any  case,  just  enough  to  keep  the  air  moving  and  prevent 
stagnation,  the  latter  condition  being  most  favourable  to  the  propagation 
of  the  dreaded  spot  and  other  fungoid  troubles. 
OdontogloBsum  deltogloesum. 
The  blossoms  of  this  species  are  very  distinct,  pretty  and  bright  in 
colour,  and  very  freely  produced.  In  habit  it  is  like  0.  gloriosum,  but 
the  flowers  are  quite  distinct.  They  occur  on  branching  spikes,  and 
are  bright  yellow  in  ground  colour  with  large  blotches  of  reddish 
brown.  It  delights  in  a  cool,  shady,  and  moist  atmosphere  all  the 
year  round,  and  the  more  light  and  air  it  has  the  better,  provided  the 
sun’s  rays  are  not  directly  on  the  plants.  The  house  in  which  these 
plants  grow  should  always  feel  pleasantly  cool  on  entering  from  the 
external  air  in  summer;  unless  it  is  so  they  will  not  long  be  satisfactory. 
Oncidium  CioesuB. 
Orchids  that  flower  in  late  summer  are  always  acceptable,  and  tl  is 
pretty  species  is  especially  welcome  owing  to  its  distinctness.  The 
flowers  are  yellow  blotched  with  brown  on  the  sepals  and  petals,  and 
in  the  centre  of  the  lip  there  is  a  deep  blackish  purple  area  that  is 
very  telling  and  showy.  Not  beiDg  a  very  strong  grower  large  pots 
are  unnecessary  for  it,  but  the  plants  do  very  well  in  the  small 
suspending  pans  i  ow  so  much  used  for  Orchids.  The  best  compost 
for  it  is  three  parts  of  clean  sphagnum  moss  to  one  of  peat.  A  few 
small  crocks  may  be  mixed  with  it,  and  the  drainage  should  fill  about 
two-thirds  of  the  depth  of  the  pan. 
Epidendrum  (Nanodes)  Medusae. 
This  is  a  most  wonderful  species,  the  blossoms  beirg  among  ihe 
most  singular  and  weird  looking  in  the  whole  Orchid  family.  They 
are  greenish  yellow  in  colour,  with  a  purple  suffusion  on  the  sepals  and 
petals,  while  the  lip  is  deep  maroon  purple  bearing  a  deep  fringe  formed 
by  the  cutting  up  of  the  lip  into  fine  filaments.  A  plant  noted  during 
the  week  was  carrying  sx  flowering  shoots  with  an  aggregate  (1 
fourteen  flowers,  and  in  this  form  it  is  very  attractive.  Being  a  native 
of  Ecuador,  quite  cool  treatment  suits  it  best. —  E.  K.  R. 
Cucunibers. 
For  a  supply  of  fruit  during  the  winter  seed  should  now  be  sown. 
There  are  many  varieties,  but  none  surpass  Telegraph,  Rochford’s 
Market,  Cardiff  Castle,  and  Syon  House  strains  in  selected  stocks. 
The  plants  from  a  sowing  made  early  in  August  will  be  fit  to  plant  out 
at  the  beginning  of  September,  and  in  a  light,  well-heated  structure 
will  commence  bearing  early  in  winter,  and  yield  a  supply  up  to  spring. 
It  is  necessary  that  the  house  be  thoroughly  cleansed,  and  the  soil  free 
from  eelworm.  For  cleansing  the  house,  especially  where  there  has 
been  fungoid  disease,  a  preparation  of  iron  sulphate  may  be  used  with 
great  advantage.  It  should  be  used  in  solution,  1  part  sulphate  of  iron 
to  20  parts  water,  with  1  part  in  450  parts  of  sulphuric  acid,  or 
water  50  gallons,  sulphuric  acid  1  pint,  iron  sulphate  25  lbs.  Prepare 
the  solution  in  a  wooden  tub  or  barrel,  as  the  sulphuric  acid  acts 
injuriously  upon  a  metal  vessel.  Place  in  the  iron  sulphate,  and  pour 
upon  it  the  sulphuric  acid,  then  add  by  degrees  the  50  gallons  of  water. 
After  the  old  soil  has  been  removed,  and  the  remains  of  a  previous  crop 
cleared  away,  the  walls  and  other  parts  of  the  house  should  be  drenched 
with  the  solution.  This  destroys  spores,  resting  or  otherwise,  with 
which  it  comes  in  contact  in  crevices  of  woodwork  or  brickwork,  or  on 
the  ground  or  floor  of  the  house.  The  treatment  must  precede 
re-occupation  of  the  house  some  time,  otherwise  the  foliage  of  the 
Cucumber  plants  would  be  injured,  if  not  completely  destroyed.  The 
solution  also  acts  well  against  animal  pests,  from  eelworms  up  to  red 
spider  and  thrips. 
Eelworms,  however,  may  be,  and  usually  are,  as  regards  root-stem 
eelworm,  Tylenchus  obtusus,  and  stem  eelworm,  T.  devastatrix,  intro¬ 
duced  in  the  soil.  They  are  associated  with  native  vegetation,  and 
almost  inseparable  from  the  roots  of  plants  passing  from  a  living  into  a 
decayed  state.  Heating  the  turf  to  a  temperature  of  212°  certainly 
destroys  present  eelworms,  as  they  succumb  to  heat  over  125°.  Baking 
the  soil,  or  even  steaming  it,  at  high  temperatures,  practically  renders 
turf  sterile,  so  that  the  heating,  if  practised,  must  not  be  excessive. 
Watering  the  soil  a  short  time  in  advance  of  planting  with  Little’s 
soluble  phenyle  or  Jeyes’  fluid,  one  ounce  to  a  gallon  of  water, 
is  generally  effective.  The  treatment  should  be  given  at  least  a 
week  in  advance  of  sowing  or  planting.  In  the  case  of  manure  it 
should  be  naturally  heated,  the  short,  fresh  material  being  thrown  into 
a  heap,  and  when  heated  so  that  the  hand  cannot  be  borne  on  it  for  a 
short  time,  turn  outside  to  inside,  top  to  bottom,  and  let  it  heat  again. 
If  then  spread  out  so  as  to  prevent  further  heating  it  will  have  lost 
very  little  manurial  value,  and  may  be  regarded  as  practically  free  from 
eelworms  or  similar  animal  pests,  therefore  suitable  for  mixing  with 
loam  for  growing  Cucumbers. —  Grower. 
Currant  Aphides. 
During  the  present  season  consirerable  damage  has  been,  and  i» 
still  being,  done  to  Currants  by  aphides  or  plant  lice.  In  some  districts 
the  bushes  are  quite  ruined,  the  leaves  turning  brown  and  shrivelled 
up,  and  the  fruit  falling  off,  the  bunches  “  shanking  ”  in  consequence 
of  the  abnormal  presence  of  these  pests.  The  rapid  increase  of  the 
“plant  lice”  is  due  to  the  recent  long  spell  of  dry,  warm  weather,  so 
favourable  to  the  development  of  these  insects,  so  detrimental  to  the 
development  of  the  fruit  and  health  of  the  bushes.  Aphides  are 
usually  more  or  less  prevalent  on  the  Currants,  and  are  always 
liable  under  certain  climatic  conditions,  such  as  existed  during  the- 
past  June,  to  increase  to  an  injurious  extent. 
Currant  bushes  should  therefore  be  washed  early  in  the  year  just 
as  regularly  as  Apple,  Plum,  and  Pear  trees.  Four  species  of  aphides, 
or  dolphins,  occur  on  the  three  kinds  of  Currants,  two  more  or  less 
confined  to  the  Currant  and  other  Ribes — namely,  the  Currant  blister 
aphis  (Rhopalosiphum  ribis  of  Linnaeus, and  Myzus  ribis  of  Linnaeus); 
the  third  species  found  is  the  Cherry  aphis  (Myzus  cerasi,  Fabricius),  a 
fourth  species  is  at  present  unidentified.  The  two  true  Ribes  species 
work  in  a  slightly  different  way.  One,  R.  ribis,  produces  reddish, 
reddish-brown,  or  yellow  blister-like  gal  s  ou  the  surface  of  the  leaves, 
whilst  Myzus  ribis  often  causes  the  leaves  to  curl  up,  especially  on  the 
top  shoots.  Both  species  are  equally  difficult  to  destroy  after  they 
commence  to  breed  in  numbers,  owing  to  their  being  hidden,  and  more 
or  less  protected  in  the  hollows  of  the  blisters  and  under  the  curled-up 
leaves.  The  galled  patches  are  chiefly  noticed  on  the  upper  surface  of 
the  leaf,  where  they  are  blister-like  ;  below  they  are  concave  In  this 
cavity  the  aphides  live  and  breed,  increasing  the  area  of  the  diseased 
patch  as  they  develop.  Numerous  blisters  may  be  formed  on  one  leaf, 
varying  in  size  from  one-fourth  to  nearly  an  inch  in  length. 
Occasionally  a  moss-like  growth  may  be  seen  inside  and  outside 
these  galls.  The  leaves  so  attacked  shrivel  away,  but  the  fruit  often 
falls  owing  to  loss  of  sap  long  before  the  leaves  die.  Neither  of  these 
aphides  are  said  to  form  much  “  boneydew,”  hence  the  diseased 
appearance  of  the  leaf  is  often  not  noticed  as  being  of  insect  origin 
during  the  early  stages  of  the  attack  unless  an  examination  has  been 
made  of  the  under  surface.  The  fruit  has  been  particularly  noticed  to 
“  run  i  ff,”  before  the  leaves  die  away,  on  poor  soil  or  where  the 
drainage  is  bad,  or  on  so-called  “  pinnocky  ”  spots  cn  the  green-sand 
soil  of  Kent.  Later  “  honeydew  ”  becomes  abundant,  being  especially 
formed  by  the  leaf-curling  species;  on  Black  Currants  the  “honey- 
dew”  often  gives  a  shiny  and  sticky  appearance  to  the  whole  bush. 
Myzus  ribis  is  especially  found  on  the  Black  Currant,  but  also  on 
the  Red  and  White,  and  sometimes  on  the  Gooseberry.  Rhopalosiphum 
ribis  is  more  often  found  on  the  Red  Currant  than  the  former  species, 
but  is  also  abundant  on  the  Black  and  White. 
The  insects  spread  chiefly  by  means  of  winged  generations,  which 
appear  every  now  and  then,  flying  fiom  bush  to  bush,  and  there  setting 
up  fresh  areas  of  disease.  These  winged  generations  may  occur  as 
early  as  the  middle  of  May,  but  usually  not  until  June.  These  two 
insects  seem  to  have  been  treated  as  one  ;  the  late  Miss  Ormerod 
merely  called  them  Aphis  ribis,  but  the  two  are  perfectly  distinct. 
Myzus  ribis  cccurs  abundantly  on  the  Continent ;  Kaltenbach  speaks 
of  it  as  destructive  in  Germany,  ana  Taschenberg  also  refers  to  it  as 
forming  lumps  and  curling  up  the  leaves.  It  appears  to  have  been 
imported  into  America,  for  Saunders  mentions  it  as  an  imported  insect. 
Lintner  also  says  it  is  destructive  in  the  States. 
Life  History. 
The  appearance  and  habits  of  the  two  commonest  Currant  aphides 
are  different,  but  their  life  history  is  very  similar. 
(I.)  Rhopalosiphum  ribis,  L. — The  wingless  viviparous  female,  or 
“  mother  queen,”  is  shiny  vreen,  mottled  with  darker  green  ;  legs, 
cornicles,  and  antennae  pale  green ;  eyes  red.  In  form  it  is  oval  and 
convex,  and  larger  than  the  lollowing  species  (II.),  the  body  being 
one-tenth  of  an  inch  long.  The  wingless  females  are  found  under 
the  leaves  and  cause  the  red,  orange,  and  yellow  blisters.  They 
appear  first  of  all  in  April,  and  occur  continuously  until  July  and 
even  August.  Every  now  and  then  the  lice  to  which  they  give 
rise  turn  into  pupae,  rudiments  of  wings  appearing  as  wing  buds. 
The  pupa  is  green,  and  does  not  differ  much  from  the  wingless 
female  or  larvae.  The  winged  viviparous  female,  which  arises  from 
the  pupa,  is  yellowish  green  with  black  head,  antennae,  joints  to  the 
legs,  black  thorax  with  a  yellow  band  in  front ;  the  abdomen  is  bright 
yellowish  green,  with  dark  spots  and  patches  on  the  dorsum  and  sides; 
yellow  honey-tubes,  swollen  towards  the  apex;  ochreous  legs  with 
dark  joints.  These  winged  temales  fly  from  bush  to  bush.  In  the 
autumn  or  late  summer  males  and  ovigerous  females  are  formed ;  the 
egg-laying  female,  after  being  fertilised,  depositing  her  lew  brown 
elongated  eg; s  on  the  last  year’s  growth  of  a  twig  just  under  the 
broken  rind  or  upon  it.  Here  the  eggs  remain  all  the  winter.  A 
