﻿48 
  THE 
  DISPERSION 
  OF 
  THE 
  GIPSY 
  MOTH. 
  

  

  to 
  the 
  large 
  traffic 
  by 
  automobiles 
  and 
  trolley 
  cars 
  from 
  the 
  badly 
  

   infested 
  district 
  in 
  eastern 
  Massachusetts, 
  it 
  is 
  very 
  probable 
  that 
  

   the 
  infestation 
  may 
  have 
  been 
  brought 
  about 
  by 
  the 
  carriage 
  of 
  cater- 
  

   pillars 
  in 
  this 
  way. 
  These 
  colonies 
  received 
  careful 
  attention 
  during 
  

   the 
  summer. 
  In 
  the 
  winter 
  of 
  1908-9 
  16 
  estates 
  were 
  found 
  in- 
  

   fested 
  with 
  a 
  total 
  of 
  32 
  egg 
  clusters. 
  Fourteen 
  of 
  these 
  estates 
  

   were 
  near 
  Worcester 
  Academy; 
  the 
  othex 
  two 
  were 
  in 
  the 
  eastern 
  

   section 
  of 
  the 
  city. 
  Only 
  a 
  few 
  egg 
  clusters 
  were 
  found 
  on 
  the 
  

   estates 
  which 
  were 
  infested 
  the 
  previous 
  year. 
  In 
  1909-10 
  10 
  in- 
  

   fested 
  estates 
  were 
  found, 
  with 
  a 
  total 
  of 
  31 
  egg 
  clusters, 
  well 
  scat- 
  

   tered 
  through 
  the 
  city. 
  Only 
  one 
  of 
  these 
  was 
  on 
  property 
  which 
  

   was 
  found 
  infested 
  the 
  previous 
  year. 
  In 
  1910-11 
  275 
  egg 
  clusters 
  

   were 
  found 
  on 
  145 
  estates, 
  every 
  section 
  of 
  the 
  city 
  being 
  included 
  

   in 
  the 
  infested 
  area. 
  In 
  1911-12 
  3,570 
  egg 
  clusters 
  were 
  found 
  on 
  

   424 
  estates. 
  It 
  seems 
  probable 
  that 
  during 
  the 
  period 
  from 
  1907 
  to 
  

   1910 
  the 
  greater 
  part 
  of 
  the 
  infestation 
  may 
  have 
  come 
  from 
  traffic, 
  

   but 
  one 
  can 
  not 
  escape 
  the 
  conviction 
  that 
  during 
  the 
  summers 
  of 
  

   1910 
  and 
  1911, 
  as 
  the 
  infestation 
  to 
  the 
  south 
  and 
  southeast 
  became 
  

   more 
  pronounced, 
  a 
  large 
  number 
  of 
  the 
  colonies 
  resulted 
  from 
  wind 
  

   spread. 
  It 
  should 
  be 
  remembered 
  that 
  the 
  chances 
  for 
  spread 
  by 
  

   traffic 
  in 
  a 
  large 
  city 
  are 
  far 
  greater 
  than 
  in 
  the 
  country 
  districts. 
  

   The 
  data 
  concerning 
  Worcester 
  are 
  given 
  because 
  the 
  city 
  resembles 
  

   many 
  of 
  the 
  towns 
  mentioned, 
  inasmuch 
  as 
  it 
  is 
  very 
  hilly, 
  so 
  that 
  

   spread 
  by 
  air 
  currents 
  is 
  very 
  probable. 
  

  

  The 
  town 
  of 
  Millbury, 
  which 
  adjoins 
  Worcester 
  on 
  the 
  south, 
  has 
  

   a 
  record 
  which 
  is 
  of 
  considerable 
  interest, 
  inasmuch 
  as 
  the 
  infesta- 
  

   tion 
  has 
  been 
  decreasing 
  from 
  year 
  to 
  year. 
  In 
  the 
  winter 
  of 
  1907-8 
  

   32 
  egg 
  clusters 
  were 
  found 
  on 
  five 
  estates. 
  These 
  were 
  all 
  located 
  

   in 
  the 
  central 
  part 
  of 
  the 
  toAvn 
  not 
  far 
  from 
  the 
  railroad. 
  The 
  

   following 
  year 
  no 
  new 
  egg 
  clusters 
  were 
  found 
  in 
  these 
  localities, 
  

   but 
  two 
  other 
  infestations, 
  containing 
  12 
  egg 
  clusters, 
  were 
  located, 
  

   one 
  near 
  an 
  infestation 
  of 
  the 
  previous 
  year, 
  close 
  by 
  the 
  railroad, 
  

   and 
  the 
  other 
  a 
  considerable 
  distance 
  west 
  of 
  any 
  previous 
  infesta- 
  

   tion. 
  In 
  the 
  winter 
  of 
  1909-10 
  three 
  new 
  infestations 
  were 
  found, 
  

   each 
  containing 
  an 
  egg 
  cluster, 
  but 
  no 
  clusters 
  were 
  found 
  in 
  the 
  old 
  

   infested 
  area. 
  In 
  the 
  winter 
  of 
  1910-11 
  nothing 
  was 
  found 
  in 
  the 
  

   area 
  infested 
  the 
  previous 
  year, 
  but 
  three 
  separate 
  infestations, 
  con- 
  

   taining 
  four 
  egg 
  clusters, 
  were 
  found 
  in 
  the 
  Bond 
  Hill 
  section 
  of 
  

   the 
  town 
  east 
  of 
  the 
  railroad. 
  In 
  1911-12 
  33 
  egg 
  clusters 
  were 
  found 
  

   in 
  six 
  localities. 
  The 
  conditions 
  in 
  this 
  town 
  are 
  quite 
  different 
  

   from 
  those 
  in 
  any 
  town 
  previously- 
  mentioned. 
  So 
  far 
  as 
  is 
  known, 
  

   no 
  bad 
  infestations 
  occurred 
  in 
  the 
  region 
  directly 
  south, 
  so 
  that 
  

   there 
  would 
  be 
  far 
  less 
  opportunity 
  for 
  spread 
  by 
  the 
  wind 
  than 
  

   would 
  be 
  the 
  case 
  in 
  the 
  other 
  towns 
  mentioned. 
  It 
  seems 
  probable 
  

  

  