﻿42 
  

  

  CIRCULAR 
  2 
  7 
  0, 
  U. 
  S. 
  DEPARTMENT 
  OF 
  AGRICULTURE 
  

  

  Destructive 
  Prune 
  Worm 
  

  

  The 
  destructive 
  prune 
  worm 
  has 
  

   become 
  a 
  rather 
  serious 
  pest 
  of 
  

   prune 
  and 
  cherry 
  trees 
  in 
  southern 
  

   Idaho 
  and 
  in 
  parts 
  of 
  Oregon. 
  

   Its 
  habits 
  are 
  somewhat 
  like 
  those 
  

   of 
  the 
  bud 
  moth. 
  The 
  partly 
  

   grown 
  brown 
  worms 
  winter 
  in 
  

   small 
  hibernacula 
  woven 
  of 
  silk 
  

   and 
  placed 
  in 
  the 
  smaller 
  crotches 
  

   or 
  in 
  crevices 
  in 
  the 
  bark. 
  These 
  

   worms 
  emerge 
  in 
  the 
  spring 
  before 
  

   the 
  flower 
  buds 
  are 
  open 
  and 
  bore 
  

   into 
  the 
  buds, 
  feeding 
  entirely 
  on 
  

   the 
  inside 
  and 
  destroying 
  many 
  

   blossoms. 
  They 
  become 
  full- 
  

   grown 
  in 
  2 
  to 
  4 
  weeks, 
  when 
  they 
  

   drop 
  to 
  the 
  ground 
  and 
  spin 
  loose 
  

   cocoons. 
  The 
  moths 
  emerge 
  from 
  

   these 
  cocoons 
  in 
  June, 
  and 
  lay 
  eggs 
  

   singly 
  on 
  the 
  lower 
  surfaces 
  of 
  the 
  

   leaves. 
  The 
  worms 
  hatching 
  from 
  

   these 
  eggs 
  burrow 
  into 
  the 
  green 
  

   prunes 
  or 
  into 
  the 
  cherries 
  and 
  

   cause 
  considerable 
  injury 
  by 
  feed- 
  

   ing 
  on 
  the 
  fruit. 
  This 
  second 
  

   brood 
  of 
  worms 
  becomes 
  full- 
  

   grown 
  late 
  in 
  July 
  or 
  early 
  in 
  Au- 
  

   gust 
  and 
  produces 
  a 
  second 
  brood 
  

   of 
  moths. 
  Worms 
  coming 
  from 
  

   eggs 
  laid 
  by 
  these 
  moths 
  feed 
  for 
  

   a 
  time 
  in 
  the 
  maturing 
  prunes 
  or 
  

   on 
  the 
  foliage 
  and 
  then 
  leave 
  it 
  

   and 
  spin 
  silken 
  nests 
  in 
  wdiich 
  they 
  

   hibernate. 
  There 
  are 
  thus 
  two 
  

   complete 
  generations 
  in 
  a 
  season. 
  

  

  No 
  satisfactory 
  measure 
  for 
  con- 
  

   trolling 
  this 
  pest 
  has 
  been 
  worked 
  

   out, 
  although 
  an 
  early 
  application 
  

   of 
  DDT, 
  before 
  the 
  trees 
  bloom, 
  

   may 
  be 
  effective. 
  

  

  Snowy 
  Tree 
  Cricket 
  

  

  The 
  snowy 
  tree 
  cricket 
  occurs 
  

   throughout 
  the 
  Pacific 
  Northwest, 
  

   but 
  has 
  been 
  of 
  economic 
  import- 
  

   ance 
  chiefly 
  in 
  southern 
  Idaho, 
  

   where 
  it 
  sometimes 
  does 
  consider- 
  

   able 
  harm 
  to 
  prunes 
  by 
  eating 
  

   holes 
  in 
  the 
  ripening 
  fruit 
  (fig. 
  

   50, 
  A). 
  Early 
  in 
  the 
  season 
  the 
  

   young 
  feed 
  on 
  the 
  foliage, 
  but 
  this 
  

  

  ^f^"' 
  * 
  

  

  

  \ 
  

  

  Figure 
  50. 
  — 
  Snowy 
  tree 
  cricket: 
  A, 
  Prune 
  

   injured 
  by 
  snowy 
  tree 
  crickets; 
  B, 
  fe- 
  

   male 
  (enlarged) 
  and 
  section 
  of 
  twig, 
  

   showing 
  egg. 
  (Photograph 
  for 
  A 
  fur- 
  

   nished 
  by 
  Idaho 
  Agricultural 
  Experi- 
  

   ment 
  Station.) 
  

  

  