﻿34 
  Twenty-eighth 
  Report 
  ok 
  the 
  State 
  Museum. 
  

  

  the 
  winding 
  and 
  branching 
  galleries 
  of 
  a 
  small 
  bark-mining 
  

   beetle, 
  an 
  insect 
  known 
  to 
  entomologists 
  as 
  the 
  Hylurgus 
  

   rufipennis 
  Kirby, 
  though 
  the 
  wings 
  are 
  by 
  no 
  means 
  always 
  

   red, 
  as 
  the 
  name 
  would 
  indicate. 
  Both 
  the 
  mature 
  insect 
  and 
  

   its 
  larvae 
  occurred 
  in 
  countless 
  numbers 
  under 
  the 
  bark 
  of 
  the 
  

   dying 
  and 
  recently 
  dead 
  trees. 
  In 
  a 
  single 
  instance 
  they 
  were 
  

   accompanied 
  by 
  a 
  much 
  smaller 
  beetle 
  of 
  similar 
  shape 
  and 
  

   habits, 
  the 
  Apate 
  rufipennis 
  Kirby,* 
  but 
  the 
  former 
  is 
  evi- 
  

   dently 
  the 
  chief 
  agent 
  in 
  this 
  unprofitable 
  business. 
  These 
  

   insects 
  excavate 
  their 
  passages 
  between 
  the 
  bark 
  and 
  the 
  wood, 
  

   eating 
  away 
  a 
  part 
  of 
  both. 
  Their 
  extended 
  work 
  is, 
  therefore, 
  

   equivalent 
  to 
  a 
  girdling 
  of 
  the 
  tree. 
  Their 
  numerous 
  galleries 
  

   form 
  an 
  intricate 
  network 
  of 
  furrows 
  on 
  all 
  sides 
  of 
  the 
  trunk, 
  

   and 
  traverse 
  one 
  of 
  the 
  most 
  vital 
  parts 
  of 
  the 
  tree, 
  the 
  newly 
  

   formed 
  and 
  forming 
  layers 
  of 
  wood 
  and 
  bark. 
  The 
  furrows 
  

   are 
  shallow 
  on 
  the 
  surface 
  of 
  the 
  wood, 
  rather 
  more 
  than 
  half 
  

   their 
  diameter 
  being 
  in 
  the 
  bark, 
  but 
  their 
  effect 
  is 
  to 
  interrupt 
  

   the 
  circulation 
  of 
  the 
  nutrient 
  juices, 
  and 
  finally 
  to 
  destroy 
  all 
  

   vital 
  action. 
  The 
  perforations 
  in 
  the 
  bark, 
  by 
  admitting 
  

   moisture, 
  doubtless 
  work 
  more 
  or 
  less 
  injury. 
  The 
  surface 
  of 
  

   the 
  sapwood 
  and 
  the 
  corresponding 
  inner 
  surface 
  of 
  the 
  bark 
  

   of 
  living 
  trees 
  are 
  discolored 
  for 
  a 
  short 
  space 
  on 
  both 
  sides 
  

   of 
  the 
  farrows, 
  as 
  if 
  the 
  injury 
  exerted 
  a 
  poisonous 
  or 
  dead- 
  

   ening 
  influence 
  on 
  the 
  tissues 
  in 
  its 
  immediate 
  vicinity. 
  This 
  

   was 
  clearly 
  seen 
  in 
  a 
  tree 
  which 
  had 
  been 
  but 
  slightly 
  injured, 
  

   there 
  being 
  but 
  few 
  furrows, 
  and 
  these 
  merely 
  longitudinal 
  

   ones 
  without 
  lateral 
  branches. 
  Each 
  occupied 
  the 
  center 
  of 
  a 
  

   discolored 
  stripe 
  about 
  half 
  an 
  inch 
  broad, 
  but 
  which 
  usually 
  

   extended 
  from 
  two 
  to 
  four 
  inches 
  up 
  and 
  down 
  beyond 
  the 
  

   extremities 
  of 
  the 
  furrows. 
  In 
  another 
  tree 
  there 
  were 
  groups 
  

   of 
  furrows 
  separated 
  by 
  considerable 
  intervals, 
  the 
  central 
  

   portions 
  of 
  which] 
  intervals 
  had 
  a 
  whitish 
  fresh 
  appearance 
  

   when 
  the 
  bark 
  was 
  first 
  peeled, 
  but 
  after 
  a 
  few 
  moments' 
  

   exposure 
  to 
  the 
  air 
  the 
  whole 
  surface 
  of 
  the 
  wood 
  had 
  changed 
  

   to 
  a 
  dull, 
  dead 
  brown 
  color, 
  indicating 
  a 
  diseased 
  or 
  unnatu- 
  

   ral 
  condition 
  of 
  the 
  surface 
  tissues. 
  The 
  foliage 
  on 
  this 
  tree 
  

   had 
  not 
  yet 
  lost 
  the 
  green 
  hue 
  of 
  life, 
  but 
  had 
  commenced 
  fall- 
  

   ing 
  to 
  the 
  ground. 
  

  

  Small 
  trees 
  are 
  rarely 
  attacked. 
  In 
  the 
  localities 
  visited, 
  

  

  * 
  I 
  am 
  indebted 
  to 
  Messrs. 
  J. 
  A. 
  Lintner 
  and 
  J. 
  L. 
  Leconte 
  for 
  the 
  entomologi- 
  

   cal 
  names 
  of 
  these 
  insects. 
  

  

  