﻿802 
  REPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  INSECTS 
  INJUEING 
  SHADE 
  AND 
  FOREST 
  TREES. 
  

  

  So 
  important 
  to 
  the 
  Western 
  Territories 
  is 
  the 
  preservation 
  and 
  calti- 
  

   vation 
  of 
  forest, 
  as 
  well 
  as 
  shade 
  and 
  ornamental, 
  trees, 
  that 
  a 
  slight 
  

   sketch 
  of 
  what 
  is 
  known 
  of 
  the 
  insects 
  found 
  in 
  Colorado 
  to 
  be 
  injurious 
  

   to 
  them 
  will 
  be 
  of 
  some 
  importance 
  until 
  more 
  definite 
  information 
  is 
  

   obtained. 
  On 
  Plate 
  LXX, 
  I 
  have 
  given 
  outline 
  figures 
  of 
  a 
  number 
  of 
  

   insects 
  either 
  found 
  living 
  in 
  forest-trees 
  in 
  Colorado, 
  or, 
  from 
  the 
  habits 
  

   of 
  their 
  allies 
  in 
  the 
  Eastern 
  States, 
  supposed 
  to 
  be 
  injurious. 
  

  

  INJURING 
  CONIFEROUS 
  TREES. 
  

  

  The 
  Spruce-Timber 
  Beetle, 
  Bryocoetes 
  affaber, 
  Manuh. 
  (Plate 
  LXX, 
  

  

  Figs. 
  1-3.) 
  

  

  This 
  beetle 
  occurred 
  (July 
  7) 
  in 
  abundance 
  in 
  all 
  stages 
  in 
  a 
  growth 
  

   of 
  AMes 
  menziesii,* 
  the 
  common 
  spruce 
  of 
  the 
  Rocky 
  Mountains, 
  at 
  

   Kelso's 
  Cabin, 
  11,200 
  feet 
  elevation, 
  on 
  the 
  road 
  to 
  Gray's 
  Peak. 
  It 
  

   bores 
  into 
  the 
  back 
  and 
  near 
  the 
  sap-wood 
  in 
  all 
  directions, 
  its 
  burrows 
  

   resembling 
  those 
  of 
  Tornicus 
  pin% 
  with 
  which 
  it 
  is 
  associated, 
  being 
  

   irregular, 
  but 
  much 
  smaller. 
  

  

  The 
  larva 
  (Plate 
  LXX, 
  Fig. 
  1) 
  is 
  cf 
  the 
  usual 
  form 
  of 
  those 
  of 
  the 
  family, 
  

   being 
  cylindrical 
  and 
  of 
  the 
  same 
  thickness 
  throughout, 
  with 
  the 
  end 
  

   of 
  the 
  body 
  full 
  and 
  suddenly 
  rounded 
  ; 
  segments 
  convex, 
  especially 
  

   the 
  thoracic 
  ones, 
  and 
  slightly 
  hairy. 
  Head 
  two-thirds 
  as 
  wide 
  as 
  the 
  

   body, 
  rounded, 
  honey-yellow. 
  Length, 
  0.15 
  inch. 
  

  

  The 
  pupa 
  is 
  much 
  like 
  that 
  of 
  T. 
  pini, 
  with 
  two 
  anal 
  soft, 
  sharp 
  

   tubercles. 
  As 
  my 
  specimens 
  are 
  farther 
  advanced 
  than 
  those 
  of 
  T. 
  pini, 
  

   the 
  wings 
  being 
  free 
  from 
  the 
  body, 
  and 
  the 
  abdomen 
  longer, 
  it 
  is 
  im- 
  

   possible 
  for 
  me 
  to 
  draw 
  up 
  a 
  good 
  description. 
  In 
  one 
  example, 
  the 
  

   pupa 
  had 
  retained 
  the 
  larval 
  head, 
  but 
  it 
  was 
  split 
  behind 
  so 
  as 
  not 
  to 
  

   interfere 
  probably 
  with 
  the 
  development 
  of 
  the 
  adult 
  beetle. 
  

  

  The 
  beetle 
  (Plate 
  LXX, 
  Fig. 
  3) 
  differs 
  from 
  T. 
  pini 
  in 
  its 
  much 
  smaller 
  

   and 
  slightly 
  slenderer 
  body. 
  The 
  head 
  and 
  prothorax 
  are 
  two-thirds 
  

   as 
  long 
  as 
  the 
  rest 
  of 
  the 
  body. 
  The 
  abdomen 
  is 
  not 
  scooped 
  out 
  at 
  

   the 
  end 
  as 
  in 
  T. 
  pini, 
  but 
  truncated, 
  moderately 
  rounded, 
  and. 
  the 
  end 
  

   of 
  the 
  abdomen 
  reaches 
  to 
  the 
  end 
  of 
  the 
  wing-covers, 
  which 
  are 
  square 
  

   at 
  the 
  end 
  instead 
  of 
  excavated 
  as 
  in 
  T. 
  pini. 
  Color 
  reddish-brown, 
  

   much 
  as 
  in 
  T. 
  pini. 
  The 
  body 
  is 
  covered 
  with 
  fine, 
  stiff, 
  straight 
  hairs. 
  

   Length, 
  0.14 
  inch. 
  

  

  \ 
  

  

  The 
  Pine-Timber 
  Beetle, 
  Tornims 
  pini 
  Say. 
  Pupa 
  and 
  beetle. 
  

   (Plate 
  LXX, 
  Figs. 
  4, 
  5.) 
  

  

  This 
  timber-beetle 
  was 
  common, 
  boring 
  irregularly 
  into 
  the 
  inner 
  

   bark 
  of 
  Ahies 
  menziesii. 
  The 
  burrows 
  are 
  like 
  those 
  made 
  by 
  the 
  same 
  

   insect 
  in 
  the 
  white 
  pines 
  from 
  Maine 
  to 
  North 
  Carolina. 
  On 
  the 
  Atlan- 
  

   tic 
  coast 
  the 
  more 
  regular 
  burrows 
  radiate 
  from 
  a 
  common 
  center. 
  

   Those 
  observed 
  on 
  Gray's 
  Peak 
  were 
  0.08 
  inch 
  in 
  diameter. 
  

  

  In 
  the 
  pupa 
  the 
  body 
  ends 
  in 
  two 
  long, 
  pointed, 
  horn-like 
  appendages 
  

   arising 
  from 
  each 
  side 
  beneath. 
  The 
  ends 
  of 
  the 
  hind, 
  tarsi 
  extend 
  to 
  

   the 
  terminal 
  third 
  of 
  the 
  wings. 
  The 
  antennje 
  are 
  clavate, 
  not 
  extend- 
  

  

  *Tbis 
  troo 
  was 
  kindly 
  identified 
  for 
  me 
  by 
  Mr. 
  Sereno 
  Watson, 
  from 
  specimens 
  of 
  

   the 
  leaves 
  and 
  cones 
  sent 
  him 
  for 
  identification. 
  

  

  I 
  

  

  