﻿14 
  

  

  THE 
  RED 
  SPIDER 
  ON 
  HOPS 
  IN 
  CALIFORNIA. 
  

   LOCOMOTION. 
  

  

  In 
  order 
  to 
  determine 
  the 
  probable 
  distance 
  that 
  an 
  adult 
  female 
  

   mite 
  is 
  capable 
  of 
  crawling 
  in 
  one 
  day, 
  experiments 
  were 
  conducted 
  

   in 
  the 
  laboratory. 
  A 
  sheet 
  of 
  paper 
  3 
  by 
  4 
  feet 
  was 
  placed 
  in 
  front 
  

   of 
  a 
  window 
  in 
  a 
  warm 
  room, 
  a 
  female 
  mite 
  placed 
  in 
  the 
  center 
  of 
  the 
  

   paper, 
  and 
  its 
  progress 
  followed 
  with 
  a 
  pencil 
  for 
  one 
  hour. 
  (See 
  

  

  Fig. 
  5.— 
  Track 
  of 
  a 
  red 
  spider 
  on 
  blotter, 
  covering 
  a 
  distance 
  of 
  40 
  feet 
  9 
  inches 
  and 
  representing 
  movements 
  

   during 
  one 
  hour. 
  Sacramento, 
  Cal., 
  1912. 
  (Original.) 
  

  

  fig. 
  5.) 
  In 
  two 
  cases 
  loose 
  soil 
  was 
  placed 
  on 
  the 
  paper. 
  Table 
  II 
  

   sums 
  up 
  the 
  results. 
  

  

  Table 
  II. 
  — 
  Distance 
  traveled 
  by 
  adult 
  female 
  red 
  spiders 
  in 
  one 
  hour 
  on 
  smooth 
  paper 
  

  

  and 
  on 
  loose 
  soil. 
  

  

  Ex- 
  

   peri- 
  

   ment 
  

   No. 
  

  

  Surface 
  used. 
  

  

  Distance 
  

   traveled. 
  

  

  Distance 
  

   gained. 
  

  

  1 
  

  

  

  Ft. 
  in. 
  

  

  22 
  4 
  

  

  23 
  8 
  

   3 
  7i 
  

  

  Ft. 
  in. 
  

  

  • 
  2 
  

  

  do 
  

  

  

  3 
  

  

  do 
  

  

  2 
  

  

  4 
  

  

  Loose 
  soil 
  

  

  11J 
  

  

  5 
  

  

  

  20 
  5 
  

  

  15 
  9 
  

  

  40 
  9 
  

  

  6 
  2 
  

  

  

  6 
  

  

  do 
  

  

  

  7 
  

  

  do 
  

  

  

  8 
  

  

  

  

  

  Average 
  for 
  paper 
  

  

  

  

  21 
  1 
  

  

  

  

  

  11% 
  

  

  

  

  6 
  2 
  

  

  

  

  

  

  The 
  surface 
  of 
  the 
  paper 
  corresponds 
  very 
  well 
  with 
  that 
  of 
  the 
  

   hopvine, 
  and 
  at 
  this 
  rate 
  an 
  average 
  female 
  mite 
  is 
  capable 
  of 
  cover- 
  

   ing 
  211 
  feet 
  of 
  vine 
  surface 
  during 
  a 
  period 
  of 
  10 
  hours. 
  

  

  