April  28,  193^, 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
371 
Entomological  Notes, 
The  Pine  Sawfly,  Lophynus  pini  (Linn). 
Pine  trees,  especially  the  Scots  Pine  and  black  Austrian  Pino, 
are  frequently  serionsly  damaged  by  the  larvae  of  sawflies.  The 
chief  culprit  is  the  Pine  sawfly  (Lophyrns  pini),  but  several  other 
species  do  considerable  harm  now  and  again.  The  Pine  sawfly 
prefers  trees  Avith  a  .sunny  aspect,  and  hence  it  Avill  be  noticed 
in  greate.st  abundance  at  the  borders  of  plantations  and  aronnd 
clearings.  Trees  from  ten  to  thirty  years  old  are  most  subject 
to  the  ravages  of  this  pest,  bnt  younger  and  older  trees  may 
sometimes  be  .seen  .severely  attacked.  The  damage  they  do  is 
soon  noticeable,  owing  to  the  larvae  feeding  in  companies  ;  these 
colonies  number  sometimes  as  many  as  a  hundred  individuals, 
but  as  the  larvm  grow  they  disperse.  The  damage  is  chiefly 
caused  by  the  larvae  eating  the  needles  ;  this  they  do  in 
two  ways,  first  by  eating  notches  out  of  the  sides  of  the 
needles,  and  later  by  eating  the  Avhole  needles  down  to 
their  base.  There  are  two  broods  during  the  year,  the 
first  of  Avhich  devour  the  one-year-old  needles  and  the 
-second  tho.se  of  the  current  year.  There  are  records  of 
the  larvae  eating  the  young  bark.  This  forest  pest  often 
attacks  large  areas  at  the  same  time.  In  one  instance 
2,000  acres  Avere  invaded.  They  often  disapiaear  suddenly; 
this  is  due  to  their  being  so  .susceptible  to  climatic 
changes,  cold  and  AAet  Aveather  being  A^ei'y  prejudicial  to 
them. 
The  parent  or 
an  inch  acro.ss  the 
four-fifths  in  the 
side  of  it  above  and  beloAv ;  the  spiracles  are  placed  in  the  lower 
pale  line.  The  sucker  feet  and  under  side  of  the  body  are  pale 
green.  AMien  full  groAvn,  they  are  rather  more  than  half  an 
inch  in  length,  and  then  form  an  oval,  pale  yelloAvish-broAvn, 
parchment-like  cocoon,  both  amongst  the  needles  and  amongst 
heather,  and  in  the  earth,  etc.,  beneath  the  trees. 
Like  the  common  Pine  saAvfly,  this  also  is  met  with  in 
colonies,  tivo  individuals  usually  .sitting  on  each  needle.  They 
pupate  in  June,  tho.se  kept  under  oli.servation  going  into  this 
stage  in  the  third  Aveek  in  June.  Although  needles  and  other 
‘‘  cover  ”  lay  on  the  ground  in  the  lireeding  cage,  they  pupated 
in  the  earth  just  as  described  by  Kollar.  The  females  AA'hich 
come  from  the.se  cocoons  lay  their  eggs  in  August  and  Septem¬ 
ber,  in  the  needles,  as  is  done  liy  L.  pini.  Apparently  the  eggs 
remain  in  the  needles  all  the  Avinter,  and  hatch  out  in  early 
May. 
It  does  not  appear  certain  that  sickly  trees  are  more 
adult  saAvfly 
Avings  in  the 
female  (Fig. 
is  nearly  three-fifths  of 
male  (Fig.  1),  and  about 
2).  The  male  is  black, 
Avith  the  apex  of  the  abdomen  reddish,  Avith  Avhite  spots 
on  the  under  side  of  the  first  segment ;  in  the  female  the 
body  is  dull  yelloAv,  Avith  three  dark  areas  on  the  thorax 
and  the  middle  of  the  abdomen  black  ;  the  legs  are  yelloAV, 
and  the  Avings  have  dusky  borders,  Avhich  are,  hoAvever, 
not  so  noticeable  in  the  fore  Avings  of  the  male.  The 
.sexes  can  most  easily  be  distinguished  by  the  male  having 
doubly  pectinate  antennae,  tho.se  of  the  female  being 
bri.stle-like. 
The  adults  nsnally  appear  early  in  May,  and  again  as 
a  second  brood  in  August.  The  female,  Avhich 
seldom  flies  OAving  to  her  heavy  build,  lays  her  eggs  in 
the  needles,  in  slits  cut  by  the  saAV-like  processes  comnion 
to  the  saAvflies.  As  many  as  from  ten  to  tAventy  may  be 
placed  in  each  needle,  but  there  are  as  a  rule  not  more 
than  six  or  seven.  It  is  said  that  one  female  may  lay  as 
many  as  120  eggs.  The  eggs  are  usually  laid  in  close 
proximity,  each  one  being  covered  over  Avith  a  resinous 
secretion,  and  so  protected  from  various  enemies.  This  resinous 
material  is  scraped  fi'om  the  leaves. 
The  larva*  hatch  in  from  tAAo  to  three  Aveeks,  appearing  at 
the  end  of  May  and  in  June;  by  the  end  of  June  or  in  July 
they  reach  their  full  fed  stage  (Fig  3),  and  then  pupate.  The 
larva;  are  nearly  an  inch  long  Avhen  full  fed,  and,  like  all  the 
larvae  of  this  genus,  they  have  tAAenty-tAvo  legs.  They  are  at 
first  pale  green,  almost  AA'hitish  beneath,  and  Avith  black  sucker 
feet,  bnt  as  they  mature  they  become  dull  broAvnish-green,  Avith 
dusky  marks  above  the  prolegs,  and  Avith  a  dark  broAvn  head ; 
the  sucker  feet  are  yelloAV,  Avith  a  broAvn  linfe  at  the  base.  The 
first  brood  feed  for  from  four  to  six  AAeeks,  and  then  pupate 
amongst  the  needles  or  in  cracks  and  crevices  of  the  bark,  the 
pupa  lying  in  a  cocoon  of  compact  broAvn  silk.  These  cocoons 
are  very  variable  in  colour,  some  being  almost  black,  others  dull 
brownisli-grey.  They  are  about  a  quarter  of  an  inch  long, 
hard  and  compact. 
In  many  cases  these  cocoons  remain  through  the  Avinter,  bnt 
as  a  rule  they  give  rise  to  a  second  brood  of  flies  in  Augmst  and 
September ;  the  progeny  of  the  second  brood  spin  their  cocoons 
mainly  amongst  the  fallen  needles,  moss,  and  heather  beneath 
the  trees.  These  ground  cocoons  often  occur  in  bunches,  and, 
like  those  of  the  fir-st  brood,  are  very  Amriable  in  colour.  The 
larvae  Avhich  make  these  cocoons  do  not  enter  the  pupal  stage 
until  the  spring.  As  many  as  .seventy  have  been  found  together 
beneath  moss  and  heather.  When  the  saAvfly  is  ready  to  emerge 
it  cuts  a  large  circular  slit  in  the  top  of  the  cocoon  and  escapes. 
Several  other  .saAvflies  attack  conifers  in  this  country,  bnt 
the  only  one  recorded  as  doing  damage  is  the  fox-coloured  saAvfly 
(Lophyrns  rufus),  Avhich  did  considerable  harm  in  Argyllshire 
to  Scots  Pines  in  1890.  Miss  Ornierod  found  in  the  Argyllshire 
outbreak  that  plants  tAvo  to  six  feet  high  Avere  mo.st  subject  to 
attack.  The  adult  female  is  reddish-broAvn,  Avith  l)lack  .spots  on 
the  thorax,  and  Avith  yelloAV  to  reddish-broAvn  legs;  the  male  is 
black.  Avith  reddish-broAvn  legs.  It  occurs  on  the  Aving  in  August 
and  September.  One  brood  only  appears  to  exist,  and  is  found 
in  larval  form  from  the  end  of  iMay  until  the  middle  or  end  of 
J  une. 
The  larvm  are  dusky  greenish-grey  Avith  black  heads,  a  pale 
line  along  the  back,  and  a  dusky  line  aa  ith  a  pale  one  on  each 
Fig.  1,  Ijoptyrus  pini.  m.ale  ;  fig.  2,  female;  fig.  3,  l.arva  ; 
Lopliyrus  rufus  ;  fig.  G,  Pine  slioot  attacked  by  .saAA’fly  larA’w. 
size  of  fig.s.  1,  2,  and  5. 
fig.  4,  cocoon  ;  fig,  5 
Lines  show  natural 
attacked  than  healthy  ones,  but  in  any  ca.se  attention  .should  bo 
given  to  maintaining  plantations  in  robust  growth.  All  the 
Pine  saAvflies  have  many  enemies.  Amongst  these  mu.st  specially 
be  mentioned  mice  and  squirrels,  Avhich  devour  large  numbers  of 
the  larva;  hibernating  in  the  cocoons  during  the  winter ;  the 
cuckoo,  goat-sucker,  and  starling  also  devour  numbers  of  the 
larva;  and  adults.  Numerous  ichneumon  flies  also  prey  upon 
them. 
When  young  trees  are  invaded,  the  larva;  may  be  easily 
destroyed  by  cru.shing  them  Avith  a  gloved  hand.  This  should 
be  attempted  in  the  early  stage  of  an  attack,  as  at  that  time 
the  larvae  are  present  in  fairly  compact  groups,  and  are  readily 
dealt  Avith.  Shaking  them  from  the  trees  on  to  cloths  spread  on 
the  ground  is  recommended,  but  is  a  less  satisfactory  method 
of  destruction.  Another  plan  is  to  place  fresh  Pine  boughs 
beneath  the  trees,  and  then  jar  tlie  larva*  off.  All  those  that 
fall  to  the  ground  collect  on  the  boughs  streAvn  about,  and  can 
then  easily  be  burnt.  Trees  that  have  been  attacked  may  have 
the  ground  aronnd  their  trunks  examined  in  Avinter,  Avhen  the 
dead  leaves,  mo.ss,  Ac.,  containing  the  cocoons  may  be  raked 
together  and  destroyed.  Ornamental  trees  in  parks  and  gar¬ 
dens  may  be  speedily  cleared  by  spraying  Avith  hellebore  Avash  or 
ar.senate  of  lead. 
The  Board  of  Agriculture  and  Fisheries  Avould  be  glad  if 
recipients  of  this  leaflet  Avould  make  it  knoAvn  to  others 
intore.sted  in  the  subject.  Copies  may  be  obtained  free  of  charge 
and  post  free  on  application  to  the  Secretary,  Board  of  Agricul¬ 
ture  and  P’isheries,  4,  Whitehall  Place,  London,  S.W.  Letters 
of  application  so  addiessed  need  not  be  stamped. 
Sedum  spectablle. 
This  is  a  distinct  and  beautiful  hardy  plant,  and  is  the  most 
popular  of  all  the  Sedums.  The  floAvers,  Avhich  are  rosy  purple, 
sometimes  Avhiti.sh,  are  formed  in  dense  corymbs,  and  contia.st 
Avell  Avith  the  broad,  glaucous,  fleshy  leaves.  It  usually  floAvers 
in  August,  and  has  good  lasting  qualities,  usually  remaining  in 
bloom  about  tAvo  months.  It  thrives  Avell  in  a  moist  and  shaded 
paid  of  the  garden. 
