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

  

  Figure 
  1. 
  — 
  Stings 
  made 
  by 
  codling 
  moth 
  

   worms 
  on 
  an 
  apple. 
  

  

  stings 
  may 
  cause 
  the 
  fruit 
  to 
  be 
  

   classified 
  as 
  culls, 
  and 
  small 
  stings, 
  

   if 
  there 
  are 
  many 
  of 
  them, 
  will 
  

   lower 
  its 
  grade. 
  

  

  LIFE 
  HISTORY 
  

  

  The 
  codling 
  moth 
  winters 
  as 
  a 
  

   worm 
  in 
  a 
  cocoon 
  (fig. 
  2, 
  A) 
  about 
  

   three-fourths 
  inch 
  long. 
  The 
  co- 
  

   coon 
  may 
  be 
  under 
  the 
  loose 
  bark 
  

   of 
  the 
  trees, 
  in 
  cracks 
  and 
  crevices 
  

   on 
  the 
  trunks, 
  attached 
  to 
  the 
  

   trunk 
  just 
  below 
  the 
  surface 
  of 
  the 
  

   ground, 
  or 
  in 
  protected 
  places 
  in 
  

  

  Figure 
  2. 
  — 
  Codling 
  moth: 
  A, 
  Larva 
  and 
  

   pupa 
  in 
  cocoons; 
  B, 
  adult. 
  Enlarged. 
  

  

  boxes, 
  sacks, 
  and 
  packing 
  sheds. 
  

   The 
  worm 
  just 
  about 
  fills 
  the 
  co- 
  

   coon 
  and 
  is 
  dirty 
  Avhite 
  or 
  pinkish, 
  

   with 
  a 
  brown 
  head. 
  The 
  last 
  

   brood 
  of 
  worms 
  that 
  leaves 
  the 
  

   fruit 
  before 
  it 
  is 
  packed, 
  and 
  a 
  

   part 
  of 
  the 
  preceding 
  brood, 
  hi- 
  

   bernate. 
  In 
  the 
  spring 
  the 
  worms 
  

   construct 
  tubes 
  of 
  silk, 
  transform 
  

   to 
  pupae, 
  and 
  later 
  to 
  moths, 
  

   which 
  escape 
  through 
  these 
  tubes. 
  

   The 
  first 
  moths 
  appear 
  about 
  the 
  

   time 
  Winesap 
  apple 
  trees 
  are 
  in 
  

   bloom, 
  and 
  the 
  largest 
  numbers 
  

   are 
  flying 
  late 
  in 
  May 
  or 
  early 
  in 
  

   June. 
  The 
  moths 
  (fig. 
  2, 
  B) 
  are 
  

   rather 
  inconspicuous, 
  having 
  a 
  

   wing 
  spread 
  of 
  about 
  three- 
  

   fourths 
  inch. 
  The 
  front, 
  or 
  upper, 
  

   wings 
  are 
  brownish 
  gray, 
  crossed 
  

   with 
  lines 
  of 
  lighter 
  gray, 
  with 
  a 
  

   bronze 
  band 
  at 
  the 
  tip. 
  The 
  hind 
  

   wings, 
  which 
  are 
  covered 
  when 
  

   the 
  moths 
  are 
  at 
  rest, 
  are 
  grayish 
  

   brown. 
  The 
  moths 
  live 
  for 
  about 
  

   2 
  weeks. 
  They 
  lay 
  most 
  of 
  their 
  

   eggs 
  between 
  sundown 
  and 
  9 
  or 
  

   10 
  p. 
  m., 
  but 
  lay 
  few 
  eggs 
  if 
  the 
  

   temperature 
  is 
  below 
  60° 
  F. 
  Most 
  

   of 
  the 
  eggs 
  are 
  laid 
  during 
  the 
  

   second, 
  third, 
  and 
  fourth 
  evenings 
  

   after 
  the 
  moths 
  have 
  emerged, 
  but 
  

   in 
  the 
  spring, 
  cool 
  weather 
  may 
  

   prevent 
  egg 
  laying 
  for 
  a 
  week 
  or 
  

   more. 
  The 
  eggs 
  (fig. 
  3) 
  are 
  pearly 
  

   white, 
  about 
  the 
  size 
  of 
  pinheads, 
  

   and 
  resemble 
  thin 
  convex 
  disks. 
  

   A 
  red 
  ring 
  appears 
  in 
  the 
  egg 
  a 
  

   few 
  days 
  after 
  it 
  is 
  laid, 
  and 
  the 
  

   day 
  before 
  the 
  worm 
  hatches 
  a 
  

   black 
  spot, 
  the 
  head 
  of 
  the 
  worm, 
  

   is 
  easily 
  seen. 
  Most 
  of 
  the 
  first- 
  

   brood 
  eggs 
  are 
  laid 
  on 
  the 
  leaves 
  

   surrounding 
  the 
  small 
  fruits. 
  

  

  Usually 
  the 
  weather 
  is 
  cool 
  

   when 
  the 
  first 
  eggs 
  are 
  laid, 
  and 
  

   the 
  worms 
  do 
  not 
  hatch 
  for 
  12 
  

   to 
  14 
  days. 
  As 
  the 
  temperature 
  

   increases, 
  the 
  incubation 
  period 
  

   becomes 
  shorter, 
  the 
  minimum 
  be- 
  

   ing 
  5 
  days. 
  Worms 
  are 
  hatching 
  

   and 
  entering 
  the 
  fruit 
  for 
  about 
  

   5 
  weeks, 
  and 
  are 
  most 
  numerous 
  

  

  