370 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
October  17, 1895. 
GLADIOLUS  CORMS  DISEASED. 
The  corms  (“  D.W.”)  arrived  in  excellent  condition,  and  on  examining 
the  first  one  we  found  an  abundanc*  of  the  white  “  insect  ”  jou  men¬ 
tioned  in  your  former  letter.  It  is  distinctly  visible  to  the  unaided  eye, 
and  clearly  defined  by  an  ordinary  pocket  lens.  It  belongs  to  the  order 
Thysanura  (Springtails)  of  the  so-called  group  Aptera,  but  that  is 
merely  a  matter  of  convenience,  and  is  named  Lipura  fimetaria.  It  is 
not  a  “jumper,”  but  a  runner,  is  about  one-tenth  of  an  inch  in  length, 
white  or  nearly  so,  and  velvety  in  texture.  It  may  be  fouud  in  damp 
earth  throughout  the  year,  especially  in  rich  soil,  or  where  there  is 
decaying  matter,  and  often  feeds  on  the  roots  of  plants,  being 
especially  fond  of  Carrots  and  Potatoes,  but  generally  associated  with 
parts  that  have  been  exposed  to  invasion  by  the  attacks  of  other  pests, 
such  as  Ecab  and  canker  spots,  as  caused  by  fungi  and  insects.  The 
insects  may,  however,  act  on  their  own  account  and  cause  decay  by  their 
depredations  on  living  tissues,  as  they  certainly  do  in  the  case  of 
“  roots,”  as  Potatoes,  but  in  your  case  they  were  confined  in  presence 
to  the  decaying  sheaths  of  the  “grass”  enveloping  the  newly  formed 
corm.  They  are  fragile  creatures  and  easily  destro}  ed  by  a  dusting  of 
freshly  slaked  lime. 
Removing  the  sheaths  from  over  the  corm  we  came  across  an  orangish- 
yellow,  leech-like  creature  of  about  the  same  size  as  the  legged  “animal” 
before  seen,  the  Lipura,  but  with  the  head  part  protruded  to  a  fine  point. 
It  is  the  larva  or  maggot  of  a  dipterous  fly,  belonging  to  the  Syrphidse, 
which  includes  some  of  the  most  useful  insects,  in  the  larval  state,  and 
some  of  the  worst  pests  of  crops.  This  pest  often  destroys  Mignonette 
plants  wholesale,  especially  in  dry  seasons,  somewhat  after  the  manner  of 
the  Cabbage  and  Onion  maggots,  the  affected  plants  dying  off  suddenly, 
withering  “  without  cause  or  reason.”  Rearing  that  up  found  on  bulbs  we 
saw  it  was  a  midge,  a  very  active  cne  too,  and  certainly  not  a  British 
species,  or  if  one,  unknown  to  the  highest  authorities  as  such.  We 
have  only  found  it  on  imported  bulbs  and  on  Mignonette  in  rich  ground, 
but  we  have  not  reared  the  latter. 
Strong  lime  water  appears  the  best  cure  for  it,  but  we  do  not  consider 
this  pest  the  cause  of  the  collapse  in  your  plants,  the  attack  being  due  to 
an  excess  of  decaying  matter  in  the  soil,  or  of  decay  set  up  in  the  corms 
by  another  creature.  The  fly  may  be  called  the  bulb  midge  (Sciara 
narcissi),  as  it  is  common  on  buds  infested  with  the  Narcissus  fly 
(Meroden  clavipes),  or  others  that  have  been  damaged,  but  your  corms 
were  not  by  anything  large,  and  we  are  loth  to  identify  them  with  the 
diseased  parts.  These,  as  you  say,  are  or  will  become  black.  It  has 
been  attributed  to  “  bacteria.”  we  have  never  found  any  but  septic,  the 
cause  or  accompaniment  of  putrefaction  in  already  dead  tissues  in  connec¬ 
tion  with  Gladioli.  There  were  no  fungal  bodies,  but  of  a  sapr.  phytic 
nature,  which  in  many  cases  are  endophytic,  and  live  on  both  dead  and 
living  tissues,  the  latter  by  their  secretions,  and  the  origin  of  this  is 
usually  in  decayed  overlying  tissues.  This  may  be  interesting  to  you 
and  other  readers  interested  in  Gladioli  culture. 
Having  examined  many  bulbs  or  corms  of  Gladioli,  we  had  a  strong 
suspicion  of  what  we  should  find — a  minute  speck  or  specks  clustered 
together,  just  or  barely  visible  to  the  unaided  eye,  but  a  person  of  keen 
eyesight  may  discern  them,  and  with  a  pocket  lens  they  appear  as  a 
translucent,  small  pinhead-sized  substance,  like  jelly.  Taking  one  of 
these  and  placing  it  in  a  drop  of  spirit,  say  brandy,  on  the  glass  slide  of 
a  microscope,  turning  on  the  light,  and  using  a  lens  of  about  fifty  lineal 
diameters,  we  found  a  six-legged  mite  parading  in  the  drop  of  spirit,  and 
in  capital  condition  for  examination.  With  a  higher  power  we  see 
what  the  works  of  Nature  and  their  Creator  are  -  more  than  wonderful. 
There  are  the  hairs  on  the  legs  and  body,  a  masterpiece  of  evolution  or 
development  for  specialised  purpose. 
It  lives  for  a  considerable  time  in  95  per  cent,  spirit,  and  is  a  wretched 
creature  to  have  on  the  human  person,  causing  intolerable  itching,  and 
even  inflammation  or  minute  smarting  blisters,  especially  near  the  eyes, 
as  it  gets  from  the  manipulating,  and  is  very  nasty.  That  is  one  of  the 
delights  of  studying  ihites,  especially  those  of  the  itch  (Sarcoptidse) 
family.  This  is  a  next-door  relative,  a  cheese  (Tyroglyphidse)  mite  family 
representative,  of  the  genus  Tyroglyphus  (Lat.),  sub-genus  Rhizoglyphus. 
It  is  Clapaiedes,  Hypopus  Dujardini  ;  Fumouse’s  and  Robin’s  Tyrogly¬ 
phus  echinopus,  Boisduval’s  Acarus  hyacinthi,  and  our  present  day 
Rhizoglyphus  echinopus. 
The  genus  is  sometimes  varied  without  “sense  or  reason,’’  all  the 
same,  it  is  the  same  thing  as  first  defined  by  Clapar^de,  and  figured  by 
Fumouse,  copied  times  out  of  number  from  Case  XIV.,  Nos.  7,  8,  9,  10, 
Natural  History  Museum  (Bethnal  Green)  branch,  there  never  having 
been  a  better  than  Fumouse’s  of  the  larvse  (six-legged),  as  given  in 
“Murray’s  Aptera,”  page  257.  It  exactly  represents  your  mite  when 
magnified  80  diameters.  An  excellent,  illustration  is  given  in  the 
Journal  of  Horticulture,  April  5th,  1888  (page  285),  of  the  perfect 
mite  (B),  but  Fumouse’s  only  is  the  correct  thing  of  the  larval  or  six- 
animal.  This  is  the  cause  of  the  disease  in  your  corms. 
The  mites  destroy  the  skin  in  places,  and  the  other  creatures — the 
springtails,  albeit  they  are  not  jumpers — and  the  maggots  come  to  the 
feast,  and  saprophytic  fungi  and  septic  bacteria  complete  the  devasta¬ 
tion,  performing  a  useful  work  in  resolving  dead  matter  into  inoffensive, 
and  hastening  the  supplies  of  food  for  vegetation.  The  mites  swarmed 
here  and  there,  and  they  have  the  advantage  of  the  other  “  beasts,”  in 
that  they  live  directly  on  the  corm,  therefore  survive  the  drying  season 
as  well  as  the  growing,  they  being  able  to  subsist  in  a  wet  soil  or  in  a 
dry  ;  but  they  like  warmth,  yet  are  not  by  any  means  uncommon  on  the 
roots  of  Clover,  or  rather  the  crowns,  and  are  introduced  in  potting  soil 
to  feed  on  the  bulbs  of  Eucharis,  and  especially  Vallotas,  also  Gladioli, 
especially  G.  Colvilli  var.  The  Bride  or  alba. 
During  the  rest  season  the  mites  barbour  at  the  base  of  the  corms, 
“  dig”  into  it  there,  and  the  plants  made  a  poor  growth  the  following 
season,  turning  yellow  in  the  grass  by  or  before  the  spike  appears,  and 
the  bloom  is  poor  or  nil.  This  is  the  work  of  the  mites,  which  fasten  od 
the  new  corm  as  the  old  parts  with  its  stored  matter  depart,  and,  as 
before  stated,  the  “  eagles  are  gathered  together  ”  to  feast  on  the  dying 
or  dead  corms.  The  question  arises,  and  it  is  an  important  one.  Is  the 
mite  imported  ?  We  believe  it  is,  for  English  Gladioli  are  much  the 
healthiest,  and  all  we  have  seen  have  bten  on  the  high-class  and  high¬ 
bred  or  tender  varieties. 
Of  course,  you  want  to  know  what  to  do.  First  burn  all  the  infested 
corms.  They  would  perhaps  live  over  the  winter,  but  the  mites  would 
feed  upon  them  and  destroy  or  greatly  impair  the  basal  part,  so  that 
they  would  start  badly,  if  at  all,  next  season.  If  you  like  to  kill  the 
mites  and  give  the  corms  a  chance  steep  them  for  an  hour  and  a  half  in 
solution  of  mercuric  bichloride  (corrosive  sublimate,  finely  powdered)  at 
a  strength  of  one  part  in  one  thousand  in  water,  in  a  wooden  (not 
metallic)  vessel,  and  remember  that  the  solution  is  a  terrible  poison,  but 
not  such  at  the  strength  named  to  cause  injury  unless  taken  into  the 
stomach.  You  may  disinfect  bulbs  or  corms  in  future  with  it,  first 
steeping  them  for  a  similar  time  in  tepid  water. 
For  the  land  apply  a  dressing  o!  quicklime,  about  ^  cwt.  per  rod, 
placing  the  freshly  burned  lime  in  little  heaps,  covering  with  a  little 
soil  till  fallen,  and  then  spread  evenly  and  dig  in  lightly  with  a  fork  in 
the  course  of  a  few  days.  This  will  make  quick  work  of  the  soft-bodied 
“  gentry  ”  in  the  soil,  and  of  the  decaying  vegetable  matter  upon  which 
they  partly  live  and  are  mainly  fostered  by.  Use  chemical  manures 
another  season,  those  advertised  being  as  good,  and  often  better,  than 
home-compounded. — G.  A. 
SMALL  MATTERS  OF  GREAT  IMPORTANCE. 
At  the  present  time,  when  the  work  of  preparing  beds  for  the 
reception  of  their  spring  flowering  plants  is  in  full  progress,  it  is 
important  to  fake  stejs  to  destroy  the  many  forms  of  insect  life  which 
usually  abound  in  liberally  manured  soil. 
This  is  especially  the  case  where  Violas  are  largely  used,  as  I  have 
often  proved  that  the  apparently  mysterious  collapse  which  takes  place 
among  them  in  the  early  summer  months  is  entirely  due  to  the  depreda¬ 
tions  of  a  greyish  coloured  grub,  which  bores  into  the  collar  of  the 
plant  just  below  the  soil.  An  effectual  remedy  for  this  evil  I  have 
found  to  be  that  of  giving  the  beds  a  good  dressing  of  freshly  slaked 
lime,  taking  care  to  thoroughly  incorporate  it  with  the  soil  as  the  work 
of  digging  proceeds.  Beds  that  have  been  manured  annually  for  a 
number  of  years  are  not  usually  deficient  in  fertility,  and  this 
occ^sional  dressing  of  lime  has  a  beneficial  effect  in  other  ways  by 
converting  into  available  plant  food  accumulated  yet  insipid  vegetable 
matter. 
Violas  are,  however,  plants  which  require  liberal  feeding  to  keep  them 
constantly  in  flower  from  April  till  August,  but  they  may  be  easily 
sustained  by  frequent  dressings  of  chemical  manures  and  soot  during  the 
growing  season.  Annual  dressings  of  manure  has  also  the  effect  of 
causing  flower  beds  to  become  too  full,  unless  the  precaution  of  removing 
some  of  the  old  soil  is  sometimes  taken,  and*  this  means  a  considerable 
amount  of  extra  labour  in  flower  gardens  of  great  size. 
An  excellent  way  of  compromising  matters,  with  beneficial  effect  all 
round,  is  to  use  chemical  manure  every  alternate  year  at  the  time  of 
digging.  Fertility  is  thus  fully  maintained  without  the  bulk  of  soil 
being  increased,  and,  moreover,  the  soil  is  kept  more  free  from  injurious 
insects  than  is  the  case  when  natural  manures  only  are  used.  While 
the  present  sp*!!  of  fine  weather  lasts,  if  these  matters  are  carefully 
attended  to,  a  good  foundation  will  have  been  laid  upon  which  to  build 
success  in  the  matter  of  spring  and  summer  bedding. — H.  D. 
GRIFFINIA  HYACINTHINA. 
This  bulbous  plant,  with  its  handsome  flowers,  is  rarely  seen  in 
private  gardens,  and  is  consequently  net  generally  known,  A  short 
time  back  a  correspondent  sent  flowers,  and  requested  information  as  to 
a  good  method  of  culture.  We  are  now  able  to  give  an  illustration 
(flg.  59),  showing  the  inflorescence,  and  to  print  the  system  of  culture 
adopted  by  one  of  the  most  successful  growers.  The  stout  scape  of 
flowers  BO  beautifully  tipped  and  edged  with  blue  and  white,  and  the 
bold  handsome  fol’age,  render  the  plants  most  charming  for  winter 
flowering,  and  it  is  remarkable  they  are  so  seldom  seen  in  gardens  where 
the  floral  display  for  the  winter  months  is  a  source  of  constant  anxiety. 
“An  intermediate  heat,  such  as  that  of  a  vinery  where  a  little  fire  is 
used,  will  answer  for  them  quite  as  well  as  a  warmer  situation,  but  they 
should  never,  except  in  hot  weather,  be  subjected  for  a  long  time  to  a 
greenhouse  temperature,  even  when  they  have  completed  their  growth 
and  are  at  rest,  or  they  are  liable  to  suffer.  The  only  drawback  to  their 
more  general  cultivation  is  difficulty  in  propagation  thiough  their  slow 
habit  of  growth,  a  circumstance  still  further  aggravated  by  keeping 
them  quite  dry  when  at  rest,  Nothing  can  be  more  injurious  to  any 
