﻿26 
  

  

  CIRCULAR 
  2 
  70, 
  U. 
  S. 
  DEPARTMENT 
  OF 
  AGRICULTURE 
  

  

  whitish 
  hairs, 
  and 
  has 
  a 
  dark 
  band 
  

   along 
  the 
  back. 
  It 
  constructs 
  a 
  

   flimsy, 
  brown 
  cocoon 
  in 
  trash 
  on 
  

   the 
  ground; 
  from 
  this 
  cocoon 
  the 
  

   moth 
  emerges 
  late 
  in 
  the 
  spring. 
  

   The 
  moth 
  is 
  usually 
  pure 
  white 
  or 
  

   dotted 
  with 
  dark-colored 
  spots. 
  It 
  

   lays 
  pale-green 
  eggs 
  in 
  a 
  flat 
  mass 
  

   on 
  a 
  leaf, 
  covering 
  them 
  with 
  

   white 
  hairs 
  from 
  its 
  body. 
  The 
  

   eggs 
  hatch 
  in 
  about 
  10 
  days. 
  

  

  Figure 
  32. 
  — 
  Nest 
  of 
  the 
  fall 
  web 
  worm. 
  

  

  There 
  is 
  only 
  one 
  brood 
  annually 
  

   in 
  the 
  Pacific 
  Northwest. 
  The 
  in- 
  

   sect 
  occurs 
  in 
  the 
  area 
  west 
  of 
  the 
  

   Cascade 
  Mountains 
  and 
  in 
  Idaho. 
  

   Apple 
  and 
  pear 
  trees 
  sprayed 
  

   regularly 
  with 
  arsenicals 
  are 
  not 
  

   harmed 
  by 
  the 
  fall 
  webworm, 
  as 
  

   the 
  caterpillars 
  appear 
  after 
  some 
  

   of 
  these 
  sprays 
  have 
  been 
  applied, 
  

   and 
  the 
  small 
  worms 
  succumb 
  

   readily 
  to 
  the 
  poison 
  on 
  the 
  foli- 
  

   age. 
  On 
  shade 
  trees 
  or 
  fruit 
  trees 
  

   not 
  ordinarily 
  sprayed, 
  a 
  spray 
  

   containing 
  lead 
  arsenate 
  or 
  50- 
  

   percent 
  DDT 
  wettable 
  powder, 
  2 
  

   pounds 
  to 
  100 
  gallons, 
  is 
  effective 
  

   if 
  applied 
  while 
  the 
  caterpillars 
  

   are 
  still 
  small. 
  The 
  caterpillars 
  

   may 
  also 
  be 
  destroyed 
  in 
  their 
  

   webs 
  by 
  burning, 
  as 
  suggested 
  for 
  

  

  the 
  tent 
  caterpillar. 
  This 
  may 
  be 
  

   done 
  during 
  the 
  day. 
  

  

  Tussock 
  Moths 
  

  

  The 
  rusty 
  tussock 
  moth 
  and 
  the 
  

   western 
  tussock 
  moth 
  are 
  leaf- 
  

   feeding 
  insects 
  found 
  chiefly 
  west 
  

   of 
  the 
  Cascade 
  Mountains. 
  The 
  

   first 
  species 
  winters 
  in 
  the 
  egg 
  

   stage 
  in 
  dry 
  leaves 
  or 
  on 
  tree 
  

   trunks 
  or 
  twigs. 
  The 
  caterpillars 
  

   appear 
  in 
  April 
  and 
  subsist 
  mainly 
  

   on 
  the 
  foliage, 
  but 
  occasionally 
  

   damage 
  the 
  fruit. 
  They 
  may 
  be 
  

   found 
  on 
  many 
  different 
  kinds 
  of 
  

   trees 
  and 
  shrulDS. 
  They 
  feed 
  for 
  a 
  

   month 
  or 
  more, 
  and 
  when 
  full- 
  

   grown 
  are 
  about 
  1 
  inch 
  long, 
  hairy, 
  

   blackish 
  or 
  bluish, 
  with 
  several 
  

   thick 
  tufts 
  of 
  hairs 
  along 
  the 
  back. 
  

   The 
  male 
  moth 
  has 
  rusty-brown 
  

   wings, 
  but 
  the 
  female 
  is 
  practically 
  

   wingless. 
  She 
  deposits 
  her 
  eggs 
  

   in 
  a 
  mass 
  on 
  the 
  cocoon 
  from 
  which 
  

   she 
  emerged. 
  A 
  second 
  brood 
  of 
  

   caterpillars 
  appears 
  late 
  in 
  July 
  

   and 
  produces 
  moths 
  in 
  September 
  ; 
  

   these 
  in 
  turn 
  deposit 
  the 
  over- 
  

   wintering 
  eggs. 
  The 
  western 
  tus- 
  

   sock 
  moth 
  has 
  similar 
  habits, 
  ex- 
  

   cept 
  that 
  there 
  is 
  but 
  a 
  single 
  brood 
  

   each 
  year, 
  the 
  eggs 
  laid 
  in 
  July 
  

   hatching 
  the 
  following 
  spring. 
  

   Special 
  control 
  is 
  seldom 
  neces- 
  

   sary, 
  since 
  sprays 
  applied 
  for 
  

   other 
  leaf-feeding 
  caterpillars 
  

   keep 
  these 
  insects 
  in 
  check. 
  Many 
  

   of 
  the 
  egg 
  masses 
  may 
  be 
  found 
  

   and 
  destroyed 
  when 
  the 
  trees 
  are 
  

   pruned. 
  

  

  Apple 
  Lacebug 
  

  

  A 
  lacebug 
  is 
  a 
  pest 
  of 
  apples 
  in 
  

   Washington 
  and 
  Oregon. 
  The 
  

   young 
  and 
  adult 
  feed 
  on 
  the 
  lower 
  

   surface 
  of 
  the 
  leaves, 
  usually 
  in 
  

   groups. 
  They 
  dot 
  the 
  leaves 
  with 
  

   black 
  spots 
  of 
  excrement, 
  and 
  as 
  

   the 
  insects 
  suck 
  out 
  the 
  juices 
  the 
  

   leaves 
  become 
  yellowed 
  and 
  even- 
  

   tually 
  drop. 
  The 
  adults 
  are 
  about 
  

   one-eighth 
  inch 
  long, 
  grayish, 
  flat- 
  

   tened, 
  with 
  lacelike 
  wings. 
  Eggs 
  

  

  