﻿78 
  DECIDUOUS 
  FRUIT 
  INSECTS 
  AND 
  INSECTICIDES. 
  

  

  Table 
  I. 
  — 
  Length 
  of 
  larval 
  stage 
  of 
  the 
  cherry 
  fruit 
  sawfly, 
  Suisun, 
  Col., 
  1910. 
  

  

  Date. 
  

  

  Observation. 
  

  

  1910. 
  

   Mar. 
  25. 
  . 
  

   Mar. 
  27. 
  . 
  

   Mar. 
  30. 
  . 
  

   Apr. 
  1... 
  

   Apr. 
  6. 
  . 
  . 
  

   Apr. 
  8. 
  . 
  . 
  

   Apr. 
  12.. 
  

   Apr. 
  10. 
  . 
  

   Apr. 
  17.. 
  

   Apr. 
  18.. 
  

   Apr. 
  19.. 
  

   Apr. 
  20. 
  . 
  

  

  34 
  larvae 
  hatched 
  in 
  cherry 
  blossoms 
  in 
  cage. 
  

  

  Supply 
  of 
  fresh 
  food 
  given 
  (branches 
  of 
  young 
  fruit 
  from 
  cherry 
  tree). 
  

  

  24 
  larvae 
  had 
  entered 
  second 
  cherry. 
  

  

  6 
  more 
  larvae 
  had 
  entered 
  second 
  cherry. 
  

  

  Fresh 
  food 
  put 
  into 
  cage. 
  

  

  10 
  larvae 
  found 
  in 
  third 
  cherry: 
  6 
  larvae 
  still 
  in 
  second 
  cherry. 
  

  

  Fresh 
  food 
  put 
  into 
  cage. 
  

  

  3 
  full-grown 
  larvae 
  left 
  fruit. 
  

  

  2 
  full-grown 
  larvae 
  left 
  fruit. 
  

   5 
  full-grown 
  larvae 
  left 
  fruit. 
  

  

  Do. 
  

  

  3 
  full-grown 
  larvae 
  left 
  fruit 
  and 
  5 
  full-grown 
  larvae 
  found 
  in 
  trash 
  at 
  bottom 
  of 
  cage, 
  

   larvae 
  had 
  left 
  fruit 
  at 
  this 
  date. 
  

  

  All 
  the 
  

  

  When 
  full 
  grown 
  (see 
  fig. 
  23, 
  c) 
  the 
  larva 
  leaves 
  the 
  fruit 
  and 
  

   works 
  its 
  way 
  into 
  the 
  ground, 
  where 
  it 
  constructs 
  a 
  small 
  parchment- 
  

   like 
  cocoon. 
  The 
  cocoon 
  will 
  be 
  found 
  from 
  3 
  to 
  7 
  inches 
  below 
  the 
  

  

  surface, 
  the 
  depth 
  

   varying 
  some- 
  

   what 
  with 
  the 
  

   texture 
  of 
  the 
  soil. 
  

   It 
  is 
  elliptical 
  or 
  

   oval 
  in 
  shape 
  and 
  

   from 
  one-fourth 
  

   t 
  o 
  three-eighths 
  

   of 
  an 
  inch 
  long. 
  

   Inside 
  the 
  cocoon 
  

   is 
  smooth, 
  dark 
  

   brown 
  in 
  color, 
  of 
  

   a 
  papery 
  texture, 
  

   and 
  somewhat 
  

   brittle, 
  especially 
  

   in 
  dry 
  soil, 
  so 
  that 
  

   it 
  is 
  easily 
  broken. 
  

   The 
  outer 
  surface 
  of 
  the 
  cocoon 
  is 
  covered 
  with 
  fine 
  particles 
  of 
  soil, 
  

   giving 
  it 
  the 
  appearance 
  of 
  a 
  small 
  clod 
  of 
  dirt. 
  In 
  Plate 
  X, 
  figure 
  2, 
  

   are 
  shown 
  full-grown 
  larvae 
  and 
  cocoons, 
  some 
  of 
  the 
  latter 
  being 
  torn 
  

   partly 
  open. 
  

  

  The 
  larva 
  remains 
  as 
  such 
  in 
  the 
  cocoon 
  until 
  the 
  following 
  winter. 
  

   Some 
  time 
  after 
  the 
  winter 
  rains 
  begin 
  it 
  transforms 
  to 
  pupa 
  and 
  

   emerges 
  the 
  following 
  March 
  as 
  adult. 
  

  

  The 
  pupa 
  has 
  not 
  been 
  observed. 
  There 
  is 
  only 
  one 
  brood 
  each 
  

   year. 
  

  

  NATURAL 
  ENEMIES. 
  

  

  Two 
  parasites, 
  an 
  ichneumon 
  and 
  a 
  rnicrobracon 
  (see 
  fig. 
  24), 
  were 
  

   obtained 
  from 
  the 
  material 
  collected 
  by 
  Mr. 
  Braucher. 
  

  

  Several 
  large 
  collections 
  of 
  infested 
  fruit 
  were 
  brought 
  to 
  the 
  

   laboratory 
  for 
  possible 
  parasites, 
  but 
  none 
  was 
  obtained 
  from 
  this 
  

  

  Fig. 
  24. 
  — 
  Microbracon 
  sp., 
  a 
  hymenopterous 
  parasite 
  of 
  the 
  cherry 
  fruit 
  saw- 
  

   fly 
  (Hoplocampa 
  cookei). 
  (Original.) 
  

  

  