442 
THE  TROPICAL  AGRICULTURIST 
[Jan,  I,  1897. 
turn  to  a manure  of  the  same  nature  as  gypsum. 
Salt  also  has  been  found  useful  for  dressing  leys 
with  in  autumn.  Laid  on  at  the  rate  of  10  cwt. 
the  acre,  and  ploughed  in,  it  has  been  found  to  kill 
the  couch-grass  (a  very  serviceable  means  of  preven- 
tion of  insect-ravage),  and  there  was  no  further 
trouble  from  either  grub  or  wireworm.  Bush-harrow- 
ing does  good,  and  paring  and  burning  tbe  surface 
is  also  an  excellent  remedy  ; but  this  has  drawbacks, 
on  account  of  the  expense  of  labour,  also  wasting 
so  much  of  what,  in  rotting,  would  have  been 
fertilizing  material. 
Where  eggs  and  maggots  are  in  the  ground,  the 
most  hopetul  method  of  meeting  coming  attack  is 
to  make  all  possible  arrangements  to  push  on  a good 
growth,  and,  firstly,  to  secure  a good  start.  This 
IS  one  reason  why  deep  ploughing  is  advised  in 
breaking  up  leys.  Some  of  the  eggs  and  young  grubs 
will  thus  be  turned  down  too  deep  to  hatch,  or  to 
make  their  way  up  again.  Also  judging  by  what 
has  been  observed  in  other  instances,  those  eggs 
which  are  well  turned  down,  out  of  reach  of  the 
amount  of  air  natural  to  them,  will  either  not 
hatch  or  be  so  much  retarded  in  date  of  hatching 
that  the  date  of  attack  will  also  be  retarded,  and 
the  youug  crop  has  a good  chance  to  get  well  estab- 
lished before  the  grubs  are  ready.  This  first  start  is 
a very  important  matter;  if  the  young  plant  is 
stunted  in  its  first  growth,  it  most  likely  will  never 
do  as  well  as  if  it  had  begun  heartily;  and  this 
point  should  be  borne  in  mind  as  one  great  method 
of  counteracting  injury  from  insect  attacks  to  roots 
or  leaves.  Get  a good  start,  by  using  good,  fresh 
seed,  by  proper  treatment  of  the  land  beforehand, 
and,  if  you  can,  by  burying  the  enemy  so  deep  down 
that  it  will  neither  uiike  its  own  way  up  at  the 
natural  time,  nor  be  lui  nedup  again  by  afterploughing 
or  cultivating  ; and  thus  we  get  our  plants  so  ahead 
in  the  race  that  we  may  hope  to  win.  This  is  a 
general  principle,  suited  to  all  crops. 
But  to  return  to  special  treatment  of  Daddy  Long- 
legs  grubs.  If  attack  is  found  to  be  bad  in  growing 
corn,  some  fertilizer,  such  as  guano  and  salt  mixed, 
applied,  say,  at  the  rate  of  4 cwt.  the  aci-e,  has 
been  found  to  do  much  good.  Nitrate  of  soda  also 
acts  well,  both  by  benefiting  the  plant  and  injuring 
the  grub.  In  experiments  tried  by  placing  Daddy 
Longlegs  grubs  at  a depth  of  one  inch  below  the 
surface,  it  was  found  that  where  nitrate  of  soda  at 
the  rate  of  2 cwt.  the  acre  was  well  watered  in, 
the  grubs  so  treated  were  very  relaxed,  soft  and 
helpless,  and  so  continued  whilst  observed  and  re- 
ported. This  helplessness  is  a very  important  point,  for 
thus  the  grub,  instead  of  creeping  away,  is  kept  under 
the  action  of  tbe  solution  good  for  the  plant  but 
bad  for  itself,  and  ultimately  dies. 
Special  chemical  applications,  only  intended  to  kill 
the  grub,  have  (in  tlie  instances  noted)  been  found 
not  to  do  good,  because  they  are  so  much  weakened 
in  passing  through  the  ground  that  tliey  are  quite 
harmless  by  the  time  they  reach  the  creature  they 
were  meant  to  kill.  This  has  been  the  case  with 
chemical  acids — carbolic  acid,  for  instance,  but 
whether  we  might  not  do  gooa  by  vegetable  appli- 
cations, such  as  that  of  mustard-cake,  is  a matter 
for  further  consideration.  The  treatment  may  shortly 
be  described  thus  prevent  egg-laying,  if  you  can  ; 
burv  eggs  and  grubs  deep  down  out  of  the  way ; 
give  your  plant  a good  start,  and  keep  it  well  up 
under  attack,  if  attack  comes.  But,  further,  we 
should  in  this,  aud  in  all  cases,  look  at  the  special 
habit  of  the  pest.  The  Daddy  Longlegs  grubs  cannot 
bear  heat,  light,  and  drought;  therefore  two  kinds 
of  treatment,  appearently  quite  opposed  to  each  other, 
have  lieen  found  useful,  for  they  both  bear  on  the 
above  habits.  Hoeing  has  been  found  useful,  because 
thus,  in  dry  sunny  weather,  the  powdery,  dry  ground 
is  just  what  tbe  “ Leather-jacket”  grub  dislikes, 
Also  rolling  at  night,  or  at  early  dawn,  does  good; 
for  then,  during  the  cool  dusk  hours,  we  may  catch 
many  of  the  grubs  on  the  surface,  and  they  may  be 
crusher  by  the  Cambridge  roller  or  Croskill’s  clod- 
crushed ; and  rolling  the  ground  firmly  in  this  way 
likewise  prevents  some  of  the  grubs  '‘travelling.’’ 
There  is  one  more  point  which  has  not  been  brought 
forward,  but  which,  by  watching  the  habits  of  the 
creature,  I think  might  be  very  usefully  worked  in 
garden  ground.  I find  the  grubs  like  to  lie  under  a 
thin  damp  turf ; they  will  collect  in  large  numbers 
in  such  a sjiot.  Probably  it  wouid  answer  well, 
in  garden-ground,  to  lay  slates,  or  tiles,  aud  send  a 
boy  round  every  morning  to  clear  what  lay  below. 
I have  only  worked  this  plan  out  myself  on  a small 
scale,  but  it  is  worth  considering.  The  above  is  one 
of  our  regular  yearly  attacks,  especially  to  be  looked 
for  after  a damp  autumn  and  winter,  because  as  we 
have  seen,  dampness  and  moisture  suit  the  Daddy 
Longlegs  in  all  their  stages. 
The  next  of  this  gnat-like  division  of  flies  that 
may  be  considered  is  the  Wheat  Midge  ( Cecidomyia 
tritici),  the  eggs  of  which  produce  the  little  orange 
or  red  footless  grub  known  as  the  “ lied  Maggot,” 
often  found  in  wheat-ears.  These  little  gnats  are 
hardly  more  than  an  eighth  of  an  inch  long  in  the 
body,  but  have  long  legs  and  horns,  and  the  female 
has  a long  ovispositor,  as  thin  as  a hair,  with  which 
she  inserts  her  eggs  in  the  wheat-florets,  or  those  of 
such  other  kinds  of  corn  or  grass  as  she  may  infest. 
This  operation  is  mostly  performed  in  the  evening, 
and  we  are  indebted  to  the  observations  of  Mr.  Swan- 
wick,  of  the  Royal  Agricultural  College  Farm, 
Cirencester,  for  the  information  that,  just  at  the 
time  of  development,  the  flies  were  not  only  attack- 
ing  the  wheat,  but  were  to  be  found  in  great 
numbers  in  clover-land  which  was  in  wheat  the 
previous  year,  and  also  amongst  rough  grass  at 
hedge-sides.  The  Maggots  soon  hatch,  aud  feed  on 
the  germ  or  some  part  of  the  soft  grain  ; they  are 
very  little  grubs,  hardly  more  than  the  twelfth  of 
an  in^h  long,  yellow,  orange,  or  scarlet  in  colour, 
and  slightly  pointed  at  the  head.  The  loss  they 
cause  by  feeding  on  the  corn-grains  sometimes 
amounts  to  as  much  as  from  one  to  about  three 
sacks  ("that  is,  about  half  a crop)  per  acre.  After 
they  have  left  off  feeding,  some  remain  in  the  corn, 
and  are  carried  wuth  it ; others  remain  in  the  stubble, 
or  fall,  or  go  down  into  the  earth,  where  in  lime 
they  change  to  crysalids,  from  which  the  Midge-flies 
come  out  about  corn-flowering  time  in  the  nexl  year. 
Our  best  method  of  prevention  is  to  destroy  the 
Red  Maggot  (for  the  chrysalis,  if  it  has  turned  to 
it)  in  its  winter  shelter.  Deep  ploughing,  such 
as  will  turn  infested  stubble  thoroughly  down,  will 
act  well,  for  once  deeply  buried  the  Gnat-fly  either 
will  not  develop  or  cannot  come  up  again.  It  is 
not  enough  considered  iu  these  matters  that  we 
may  by  our  own  common  knowledge  often  guide 
ourselves.  If  a weak  small  grub  (so  small  that  we 
can  scarcely  see  it)  has  a weight  of  earth  put  on 
it,  somewhere  about  as  much  as  if  at  least  thirty 
or  forty  yards  deep  of  earth  were  placed  on  one 
of  ourselves,  it  is  very  unlikely  that,  where  it  is 
not  specially  supplied  with  powers  for  piercint'  the 
ground,  it  will  come  up  again  as  a grub ;°  and 
the  Gnat-iMidge,  if  it  does  develop,  certainly 
cannot  make  its  way  through.  This  is  one  of  the 
points  that  show  us  how  to  keep  insects  in  clieck  • 
we  need  often  merely  to  consider  just  what  is  be- 
fore our  eyes  and  act  on  it.  Once  down,  and  left 
down  (for,  of  course,  if  we  bring  the  grubs  up  again 
by  a second  equally  deep  ploughing  we  lose  our 
labour),  we  have  in  all  probability  buried  the  com- 
ing attack  safely  away.  All  measures  which  will 
lessen  the  amount  of  couch-grass,  or  other  wild  grass 
(it  is  either  known  or  believed,  to  lie  in  the  heads’ 
or  shelter  at  the  roots  during  winter),  would  help 
to  keep  tbe  amount  of  this  midge  in  check.  Clear- 
ing and  burning  rou-b  grass  by  hedge-sides  is  one 
niethod  ; gathering  up  the  corn-stubble  and  burning 
it,  directly  the  corn  is  harvested,  gets  rid  of  what- 
ever is  at  the  roots;  and  also  (and  this  is  very 
important)  all  the  dust  from  the  threshing-machine 
should  be  burnt  where  wheat  is  known  to  bo  at  all 
infested.  The  Red  Maggot  may  often  be  seen  in 
millions  m this,  and  absence  of  attack  has  been 
found  to  follow  the  plan  of  carefully  burning  the 
infested  dust. 
