Ladybirds  ; Lace-wing  and  Hover  Flies.  279 
with  six  longish  legs,  and  with  yellow  spots  on  its  back, 
and  the  accompanying  figure  will  perhaps  enable  it  to  be 
identified.  The  lace-wing  fly,  or  “ golden  eye,”  is  not  so  often 
noticed,  and  when  seen  it  appears  far  too  fragile  a creature 
to  he  of  much  service  against  green  fly.  It  is  of  a delicate 
blue-green  colour,  with  transparent  wings  much  interlaced  by 
veins,  while  its  golden  eyes  are  very  conspicuous  ; but  though 
a beautiful  insect,  it  is  capable  of  emitting  a very  disagreeable 
smell.  Its  grub  is  sometimes  called  the  aphis  lion  on  account 
of  the  voracity  with  which  it  destroys  green  fly.  It  is  not 
very  unlike  a ladybird  grub,  but  is  narrower  and  more  pointed 
in  front,  and  is  without  the  yellow  spots  on  the  back.  The 
eggs  of  these  insects  are  very  curious,  and  are  no  doubt  often 
seen  without  their  nature  being  recognised.  They  are  little 
white  bodies  at  the  end 
of  stalks  which,  in  the 
common  species,  are 
about  a quarter  of  an 
inch  long,  and  a cluster 
of  them  much  resembles 
some  large  variety  of 
mould.  If  these  eggs 
ai-e  noticed  on  a plant 
they  ought  by  no  means 
to  be  removed.  Hover 
flies,  so  called  from 
their  habit  of  remain- 
ing perfectly  stationary  (C,  after  D.  sharp,  Cambridge  Natural  History.) 
in  the  air  over  a plant,  are  two-winged  insects,  with  flat  bodies 
marked  with  wasp-like  yellow  bands.  When  hovering,  they 
are  not  searching  for  prey  on  their  own  account,  but  are 
seeking  aphis-infested  leaves  on  which  to  deposit  their  eggs. 
These  hatch  out  into  curious,  legless,  almost  transparent  grubs, 
which  immediately  set  to  work  among  the  young  green  fly. 
Many  ichneumon  flies  also  prey  upon  aphids,  and  by  all 
these  agencies  the  pest  is  generally  kept  within  bounds  in 
a normal  season,  but  in  prolonged  dry  weather,  though  the 
insect  enemies  do  their  best  they  are  unable  to  cope  with  the 
tremendous  rate  of  increase  in  the  blight,  and  the  plants, 
deprived  of  their  necessary  moisture,  ai’e  not  so  well  able 
to  I’esist  attack. 
A particulai-ly  bad  year  for  blight  does  not  seem  to  make 
a recurrence  of  the  attack  any  more  likely  for  the  succeed- 
ing year.  As  the  green  fly  multiplies,  its  parasites,  finding 
abundance  of  food,  increase  likewise,  and  towards  the  end 
of  the  attack  may  be  numerous  enough  to  leave  few  survivors ; 
there  is  therefore  little  occasion  for  preventive  measures,  though 
Fig.  2.— a,  Lace-wing  fly.  B,  Eggs.  C,  Larva  or 
