358  Annual  Report  for  1909  of  the  Zoologist. 
them  on  their  own  account,  and  the  grower  believes  that  they 
have  accounted  for  a large  number  of  the  caterpillars. 
An  attempt  was  also  made  to  catch  the  moths  by  the  use  of 
trap-lamps.  As  a rule  this  measure  is  not  advisable,  and 
elaborate  investigations  by  various  entomologists  have  proved 
it  to  be  in  some  cases  not  only  useless,  but  harmful,  for  the 
useful  insects  captured  by  the  lamps  often  exceed  in  number 
those  that  are  injurious,  while  of  the  latter,  many  of  those  that 
are  caught  are  either  males,  or  have  already  laid  their  eggs. 
Nevertheless  there  are  cases  in  which  the  expedient  may  be 
worth  trying,  and  in  the  present  instance  circumstances  seem 
to  be  favourable.  These  moths  belong  to  a group  strongly 
attracted  by  light,  and  the  use  of  the  lamps  might  be  confined 
to  the  few  days  during  which  the  majority  of  the  moths 
emerge.  Just  at  this  period  it  is  probable  that  many  of  the 
moths  would  be  caught  and  comparatively  little  harm  would 
be  done  by  the  trapping  of  useful  insects.  Caterpillars  bred  out 
in  captivity  emerged  as  moths  in  the  middle  of  August. 
In  September,  some  specimens  of  hop  cones  were  sent  for 
examination  with  the  complaint  that  much  damage  was  being 
done  by  the  “ strig  maggot.”  In  1891  and  1892  the  late  Miss 
Ormerod  called  attention  to  this  pest,  but  since  that  time  it 
seems  to  have  escaped  the  observation  of  entomologists.  As 
far  as  I know,  the  mature  insect  whose  grub  does  the  injury 
has  not  yet  been  seen  and  identified.  The  grub  is  evidently 
that  of  a “ midge,”-  a small  fly  of  the  same  group  as  the  pear- 
midge  {Cecidomyidce).  Our  present  knowledge  of  the  pest 
amounts  to  this,  that  in  September  hop  cones  are  often  seen  to 
wither  and  turn  brown  on  account  of  the  work  of  a small 
maggot  which  feeds  in  the  “ strig  ” or  central  stem  of  the  cone, 
and  that  these  maggots  leave  the  cones  towards  the  end  of 
September  and  fall  to  the  ground  to  bury  themselves  in  the 
soil.  As  is  the  case  with  others  of  their  kind,  they  have  the 
power  of  “ skipping,”  and  can  thus  distribute  themselves  over 
a fairly  wide  area.  Apparently  it  is  a wet  season  pest,  for 
severe  attacks  have  nearly  always  occurred  after  a particularly 
rainy  summer. 
Even  this  meagre  knowledge  of  the  habits  of  the  insect, 
supplemented  by  what  we  know  of  others  of  the  same  group, 
indicates  quite  clearly  the  line  which  preventive  measures 
must  take.  Inside  the  hop  cone  the  grub  is  invulnerable,  and 
no  amount  of  washing  would  be  likely  to  disturb  it.  Nor  does 
there  seem  to  be  any  hopeful  method  of  preventing  the  fly 
from  laying  its  eggs  in  the  cones.  Obviously  the  one  chance 
of  destroying  it  is  to  treat  the  soil  in  some  way  which  shall  kill 
the  grubs  which  have  buried  themselves  in  it  to  turn  to 
chrysalids.  The  really  important  point  which  remains  to  be 
