﻿18 
  THE 
  EED 
  SPIDER 
  ON 
  HOPS 
  IN 
  CALIFORNIA. 
  

  

  Even 
  when 
  they 
  can 
  be 
  picked 
  the 
  quality 
  is 
  often 
  severely 
  injured. 
  

   Dr. 
  W. 
  W. 
  Stockberger, 
  of 
  the 
  Bureau 
  of 
  Plant 
  Industry, 
  reports 
  

   upon 
  some 
  samples 
  of 
  "spider 
  hops" 
  as 
  follows: 
  

  

  Of 
  these 
  No. 
  1 
  is, 
  I 
  should 
  say, 
  practically 
  unsalable. 
  Not 
  only 
  is 
  the 
  color 
  very 
  

   poor, 
  but 
  it 
  is 
  not 
  uniform 
  and 
  shows 
  very 
  evidently 
  the 
  red 
  discoloration 
  produced 
  

   by 
  the 
  activities 
  of 
  the 
  "spider." 
  The 
  aroma 
  is 
  also 
  far 
  from 
  pleasing. 
  The 
  second 
  

   sample, 
  which 
  showed 
  some 
  damage 
  by 
  the 
  spider, 
  is 
  far 
  from 
  being 
  a 
  first-class 
  hop; 
  it 
  

   of 
  course 
  is 
  still 
  marketable. 
  

  

  Thus, 
  even 
  though 
  a 
  large 
  crop 
  is 
  harvested 
  its 
  value 
  may 
  be 
  

   greatly 
  reduced 
  by 
  the 
  injury 
  due 
  to 
  the 
  attack 
  of 
  the 
  red 
  spider. 
  

  

  EFFECT 
  UPON 
  MAN. 
  

  

  Some 
  of 
  the 
  workmen 
  of 
  the 
  hop 
  ranches 
  stated 
  that 
  during 
  hop 
  

   picking 
  they 
  had 
  been 
  troubled 
  by 
  the 
  mites 
  getting 
  upon 
  their 
  

   bodies 
  and 
  causing 
  an 
  irritation. 
  This 
  point 
  was 
  investigated; 
  

   several 
  hundred 
  mites 
  were 
  liberated 
  upon 
  the 
  hands 
  and 
  arms 
  of 
  

   the 
  writer 
  and 
  allowed 
  to 
  crawl 
  around 
  for 
  20 
  minutes. 
  A 
  barely 
  

   detectable 
  itching 
  was 
  the 
  only 
  sensation 
  observed. 
  The 
  irritation 
  

   mentioned 
  by 
  the 
  men 
  was 
  probably 
  due 
  to 
  scratches 
  of 
  the 
  hop- 
  

   vines 
  and 
  not 
  to 
  any 
  irritation 
  caused 
  by 
  mites. 
  

  

  DISTRIBUTION 
  IN 
  THE 
  FIELD. 
  

  

  It 
  was 
  the 
  opinion 
  of 
  some 
  hop 
  growers 
  that 
  the 
  red 
  spider 
  appeared 
  

   first 
  along 
  the 
  roads 
  and 
  fences 
  and 
  gradually 
  worked 
  into 
  the 
  fields, 
  

   but 
  observations 
  in 
  several 
  localities 
  did 
  not 
  bear 
  out 
  this 
  point. 
  

   The 
  mites 
  first 
  appeared 
  within 
  the 
  hopyards 
  and 
  not 
  especially 
  

   along 
  the 
  borders, 
  and 
  although 
  the 
  increase 
  was 
  rapid, 
  the 
  infestation 
  

   was 
  evenly 
  distributed. 
  

  

  The 
  dust 
  from 
  the 
  roads 
  collecting 
  on 
  the 
  foliage 
  made 
  the 
  web 
  

   show 
  very 
  distinctly, 
  and 
  the 
  growers, 
  judging 
  the 
  extent 
  of 
  an 
  

   infestation 
  by 
  the 
  amount 
  of 
  web 
  that 
  can 
  be 
  seen, 
  would 
  naturally 
  

   think 
  that 
  the 
  infestation 
  started 
  where 
  the 
  web 
  was 
  most 
  noticeable. 
  

   This 
  accounts 
  for 
  the 
  erroneous 
  opinion 
  mentioned 
  above. 
  

  

  Mr. 
  W. 
  H. 
  Volck, 
  who 
  made 
  some 
  observations 
  upon 
  the 
  red 
  spider 
  

   at 
  Wheatland, 
  Cal., 
  in 
  1902, 
  suggested 
  that 
  since 
  the 
  infestation 
  was 
  

   so 
  sudden 
  the 
  mites 
  might 
  possibly 
  have 
  traveled 
  through 
  the 
  air 
  

   on 
  webs, 
  like 
  the 
  "balloon" 
  spiders. 
  To 
  test 
  this 
  point 
  four 
  dozen 
  

   sheets 
  of 
  tanglefoot 
  fly 
  paper 
  were 
  tacked 
  to 
  the 
  trellis 
  poles 
  in 
  

   various 
  parts 
  of 
  the 
  infested 
  yards 
  at 
  Perkins, 
  Cal. 
  They 
  were 
  put 
  

   out 
  in 
  June, 
  1911, 
  and 
  when 
  collected 
  in 
  September 
  many 
  insects 
  

   were 
  found 
  embedded 
  in 
  the 
  hardened 
  tanglefoot, 
  but 
  no 
  mites 
  were 
  

   observed. 
  During 
  the 
  migrations 
  in 
  August 
  mites 
  dropping 
  from 
  

  

  