June  j,  1893.] 
THE  TROPICAL  AGRICULTURIST. 
789 
PLANT  PESTS  AND  INSECTICIDES, 
One  of  the  most  costly  and  unprofitable  of  all  the 
operations  in  a garden  up  to  less  than  a score  of 
years  ago,  and  one  still  too  frequent,  was  the  never- 
ending  round  of  washing,  scrubbing,  and  cleaning 
insect-infested  plants.”  The  costliness  mainly  arose 
from  the  high  price  of  the  “ insecticides,”  or  the 
inefficiency  of  those  commonly  employed,  and  the 
great  amount  of  labour  expended  in  applying  them  ; 
and  the  unprofitableness,  chiefly  because  of  the 
severe  treatment  the  plants  received  under  the  fre- 
quent scrubbing  and  rubbing  to  which  they  were 
subjected,  and  the  general  want  of  care  and  thorough- 
ness in  carrying  out  the  cleaning  process.  More 
money  was  often  spent  in  futile  attempts  to  free 
plants  from  insect  pests  than  would  have  bought 
clean,  healthy  Stock  of  the  same  size  in  the  open 
market.  Unless  the  rarity  or  value  of  a plant  will 
justify  the  cost  of  carefully  cleaning  it,  when  plants 
from  any  cause  get  into  such  a disreputable  state 
of  filth  and  insects,  they  should  be  promptly  placed 
in  the  nearest  furnace,  and  burned  along  with  their 
dirt  and  vermin. 
At  the  present  time,  when  the  depression  in  trade 
and  rural  affairs  makes  it  a necessity  in  most  gardens 
to  keep  down  expenditure  to  the  lowest  limits  consistent 
with  efficiency,  the  strictest  economy  has  to  be 
practised  in  all  departments.  In  few  garden  oper- 
ations can  more  economy  be  generally  carried  out 
than  in  the  timely  prevention  or  arrest  of  insect 
and  fungoid  attacks.  From  want  of  forethought  in 
applying  simple  and  effective  remedies,  these  pests 
are  too  often  allowed  to  get  a firm  hold  upon  plants, 
and  even  permitted  to  overrun  a house  and  some- 
times a whole  range  of  houses,  before  a serious 
thought  is  given  to  them,  or  a finger  lifted  to  repel 
their  attack.  By  promptly  applying  a remedy,  the 
outbreak  might  nevertheless  have  been  stamped  out 
in  its  infancy  in  a few  minutes.  Effective  means 
and  prompt  action  comprise  the  whole  secret  of 
success  and  economy  in  dealing  with  insect  as  well 
as  fungoid  pests. 
It  is  now  well-known  to  many  gardeners,  and 
should  be  known  by  all  horticulturists,  that  petroleum 
is  one  of  the  best  and  cheapest  of  all  insecticides  ; 
but  its  liability  to  abuse  by  the  ignorant  or  careless 
makes  the  general  use  of  it  rather  risky  in  unskilled 
hands,  in  which  it  is  always  dangerous,  and  some- 
times deadly  in  its  effect  upon  plants.  To  avoid 
this,  the  strength  of  the  petroleum  must  be  carefully 
reduced  to  the  point  at  which  it  will  kill  the  insects 
without  injuring  the  plant  on  which  they  live.  It 
is  a curious  but  most  important  fact  in  Nature,  that 
petroleum  may  be  so  graduated  in  strength  that  it 
will  kill  every  insect  it  reaches  which  infests  or 
preys  upon  plant  life,  without  injury  to  the  plant, 
or  part  of  a plant,  on  which  the  insect  lives.  Thus, 
a very  weak  admixture  of  the  oil  applied  to  aphids 
—say  green-fly  on  a Rose  shoot,  or  any  other  tender 
young  growth  which  aphides  affect,  will  kill  the 
fly,  and  not  injure  the  growth.  About  J gill  of 
paraffin  oil  thoroughly  blended  with  1 gallon  of  soft 
water  will  destroy  all  aphides;  but  even  half  that 
quantity  of  paraffin  in  a gallon  of  liquid  will  do 
the  same,  if  it  is  perfectly  amalgamated  with  the 
water  and  properly  applied  in  the  form  of  spray. 
As  a rule,  red-spider  and  thrips  do  not  appear  on 
younger  growth,  although,  if  not  prevented,  they 
quickly  overrun  it.  Older  growth,  such  as  fresh 
full-grown  foliage  of  Vines,  Peaches,  and  the  like, 
are  apt  to  be  infested  with  them,  and  may  be  treated 
with  } gill  of  paraffin  in  the  gallon  of  liquid  without 
fear  of  injury  to  the  growth,  but  with  deadly  con- 
sequence to  the  spider  and  thrips.  For  eradicating 
mealy-bug,  scale,  and  similar  pests,  which  chiefly 
infest  the  tough,  leathery  foliage,  and  firm  woody 
parts  of  a host  of  stove  and  greenhouse  plants,  1 
gill  of  paraffin  in  the  gallon  of  liquid  may  be  safely 
employed,  and  if  regularly  and  judiciously  applied 
it  will  effectually  keep  them  clear  of  every  insect 
pest. 
Among  the  various  methods,  most  of  which  are 
failures,  in  vogue  for  reducing  the  strength  of  paraffin 
to  make  it  safe  for  use  as  an  insecticide,  one  of  the  * 
safest  and  handiest  is  the  method,  now  pretty  well 
known  among  horticulturists,  of  boiling  black  soap 
and  water,  in  the  proportion  of  one  of  soap  to  eight 
of  water,  till  the  soap  is  wholly  dissolved  ; and 
then,  while  the  liquid  is  as  near  the  boiling  point 
as  possible,  pouring  it  into  bottles,  and  at  the  same 
time  adding  the  paraffin.  The  nearer  the  liquid  is 
to  the  boiling  point  at  the  moment  the  paraffin  is 
poured  into  it,  the  better  will  the  whole  amalgamate. 
A fixed  quantity  of  the  oil  is  put  into  each  bottle, 
so  that  the  exact  strength  is  known.  Corked,  and 
set  aside  in  a safe  place,  it  is  ready  when  required 
to  be  reduced  to  a proper  strength  for  use.  In  pre- 
paring for  application,  it  is  simply  poured  into  a pail, 
watering-can,  or  garden-engine,  as  may  be  required, 
and  with  soft  water  it  is  reduced  to  the  desired 
strength.  If,  say,  a bottle  contains  two  gills  of 
praffin,  it  is  enough  for  making  four  gallons  of  water 
sufficiently  strong  for  spraying  plants  to  clear  them 
of  aphids;  or  two  gallons  for  clearing  off  red-spider 
and  thrips ; and  one  gallon  for  eradicating  mealy 
bug  and  scale  insects.  With  a little  practice,  this 
simple  and  effective  method  of  reducing  the  strength 
of  paraffin  may  be  safely  performed  by  any  intelligent 
person,  although  entirely  ignorant  of  chemistrv.  In 
these  days,  however,  of  evening  classes  and  technical 
education,  every  young  gardener  ought  to  acquire 
a sufficient  knowledge  of  chemistry  to  enable  him  to 
clearly  understand  the  nature  of  the  process  by 
which  paraffin  amalgamates  with  water,  when  com- 
bined with  black  soap  at  a high  temperature. 
All  l'guid  insecticides  of  a caustic  nature  are  best 
applied  in  the  form  of  spray,  either  through  a garden 
engine,  syringe,  sprayer,  or  other  similar  appliance. 
One  of  the  most  effective  of  all  the  appliances  for 
this  purpose  is  the  Stott  spraying-nozzle,  which  can 
be  screwed  on  to  any  form  of  sprayer,  syringe,  or 
garden  engine,  and  which  distributes  the  liquid  evenly, 
safely,  and  economically,  wherever  it  is  required. 
In  particular,  paraffin,  of  whatever  strength,  as  an 
insecticide,  should  always  be  applied  in  a spray,  and 
never,  if  it  possibly  can  be  avoided,  in  any  other  way, 
because  all  dipping  or  washing  of  plants  with  it,  is 
extremely  liable  to  injure  them.  A slight  film  of 
paraffin  may  be  floating  on  the  surface  of  the  most 
perfectly  blended  liquid,  or  some  crude  sediment 
may  fall  to  the  bottom,  and  in  either  case  dipping 
or  washing  with  it  is  dangerous,  especially  so  to 
downy  or  hairy-leaved  plants.  Numerous  mishaps  of 
this  kind  have  occurred  which  it  is  safe  to  say 
would  never  have  happened  if  the  insecticide  had 
been  applied  in  fine  spray,  even  by  the  ordinary 
method  of  using  the  forefinger  as  a “sprayer”  on 
the  jet-nozzle  of  a common  syringe.  Still,  a care- 
less person  with  a jet-nozzle  may  easily  play  mis- 
chief, but  with  a “ Stott  ” nozzle  for  spraying  the 
liquid  paraffin  mixture,  the  risk  of  a mistake  is 
rendered  as  near  as  possible  an  impossibility.  Many 
plants,  when  in  a dormant  state,  absorb  this  oil  like 
a sponge  1 While,  when  growing,  and  full  of  sap, 
it  cannot  penetrate  to  the  living  parts,  because  the 
sap  or  moisture  repels  it.  Hence  Vines,  and  all 
such  open,  porous-wooded  plants,  are  easily  injured 
by  paraffin,  even  of  a weak  strength,  when  dormant, 
while  a much  stronger  solution  may  be  safely  ap- 
plied to  them  when  they  are  growing  and  full  of 
sap.  By  bearing  these  simple  facts  in  mind,  any 
intelligent  person  may  keep  plants  of  all  kinds  free 
from  insect  pests  at  a minimum  cost. — Gardeners’ 
Chronicle. 
CONSUMPTION  OF  COCONUTS. 
A writer  in  the  “Times”  while  taking  over  the 
interesting  information  on  this  subjeot  afforded 
in  Wednesday’s  Observer,  thinks  the  estimate  of 
219  million  nuts  consumed  in  households  in  Ceylon 
ever y year  as  far  too  high  and  continues;  — 
We  cannot  believe  that  every  single  inhabitant  of 
this  Island  uses  73  coconuts  per  annum  1 Why,  large 
numbers  of  the  inhabitants  hardly  use  any  at  all. 
In  the  North-Central  Province  and  in  parts  of  Uva 
the  inhabitants  hardly  know  what  coconuts  are,  and 
to  believe  that  the  one  million  inhabitants  of  the 
