﻿EECOMMENDATIONS. 
  61 
  

  

  By 
  far 
  the 
  greatest 
  dispersion 
  is 
  due 
  to 
  the 
  fact 
  that 
  first-stage 
  

   caterpillars 
  are 
  blown 
  by 
  the 
  wind. 
  A 
  glance 
  at 
  the 
  present 
  infested 
  

   territory 
  shows 
  that 
  dispersion 
  has 
  been 
  along 
  the 
  line 
  of 
  the 
  prevail- 
  

   ing 
  winds 
  immediately 
  following 
  the 
  hatching 
  of 
  the 
  caterpillars. 
  

   One 
  condition 
  favoring 
  wind 
  spread 
  is 
  the 
  presence 
  of 
  large 
  woodland 
  

   colonies 
  which 
  are 
  overpopulated 
  with 
  caterpillars. 
  This 
  stimulates 
  

   activity 
  on 
  the 
  part 
  of 
  the 
  insects 
  in 
  search 
  of 
  food 
  and 
  affords 
  oppor- 
  

   tunities 
  for 
  them 
  to 
  be 
  carried 
  away 
  by 
  the 
  wind. 
  High 
  temperature 
  

   increases 
  the 
  activity 
  of 
  the 
  caterpillars, 
  and 
  this 
  tends 
  to 
  increase 
  the 
  

   chances 
  of 
  their 
  being 
  blown 
  away. 
  Weather 
  records 
  for 
  the 
  past 
  10 
  

   years 
  show 
  that 
  the 
  prevailing 
  winds 
  during 
  April 
  and 
  May, 
  when 
  the 
  

   temperature 
  is 
  high 
  enough 
  to 
  make 
  the 
  caterpillars 
  sufficiently 
  active, 
  

   and 
  when 
  the 
  wind 
  is 
  strong 
  enough 
  to 
  blow 
  them 
  for 
  any 
  great 
  

   distance, 
  are 
  for 
  the 
  most 
  part 
  from 
  the 
  south 
  and 
  southwest. 
  

  

  The 
  character 
  of 
  the 
  food 
  has 
  a 
  very 
  important 
  bearing 
  on 
  the 
  

   dispersion 
  of 
  this 
  insect, 
  because 
  unless 
  caterpillars 
  that 
  are 
  blown 
  

   by 
  the 
  wind 
  are 
  able 
  to 
  find 
  lodgment 
  on 
  favorable 
  plants 
  they 
  will 
  

   not 
  survive, 
  and 
  there 
  will 
  be 
  no 
  opportunity 
  for 
  the 
  species 
  to 
  become 
  

   established. 
  If 
  a 
  number 
  of 
  first-stage 
  caterpillars 
  were 
  dropped 
  by 
  

   the 
  wind 
  into 
  a 
  forest 
  of 
  solid 
  pine 
  they 
  would 
  not 
  be 
  able 
  to 
  establish 
  

   a 
  colony, 
  because 
  these 
  small 
  caterpillars 
  can 
  not 
  survive 
  on 
  pine 
  

   foliage. 
  There 
  are 
  other 
  trees, 
  particularly 
  conifers, 
  which 
  are 
  

   equally 
  immune 
  from 
  injury 
  by 
  the 
  first-stage 
  caterpillars, 
  and 
  upon 
  

   which 
  they 
  are 
  not 
  able 
  to 
  develop. 
  This 
  shows 
  that 
  large 
  blocks 
  of 
  

   unfavorable 
  food 
  plants 
  will 
  not 
  only 
  prevent 
  the 
  establishment 
  of 
  

   ihe 
  insect, 
  but 
  that 
  such 
  woodland 
  will 
  require 
  no 
  treatment 
  what- 
  

   ever, 
  provided 
  it 
  is 
  isolated 
  by 
  removing 
  the 
  favored 
  food 
  plants 
  

   near 
  by. 
  

  

  RECOMMENDATIONS. 
  

  

  As 
  a 
  result 
  of 
  the 
  experiment- 
  which 
  have 
  been 
  conducted 
  and 
  a 
  

   study 
  of 
  the 
  data 
  which 
  have 
  been 
  secured, 
  the 
  following 
  recommenda- 
  

   tions 
  are 
  made, 
  as 
  these 
  have 
  a 
  practical 
  bearing 
  on 
  the 
  gipsy-moth 
  

   problem 
  : 
  

  

  (1) 
  National 
  legislation 
  should 
  be 
  enacted 
  to 
  provide 
  for 
  the 
  

   inspection 
  of 
  lumber 
  products 
  or 
  other 
  material 
  which 
  i- 
  likely 
  to 
  

   carry 
  the 
  gipsy 
  moth 
  from 
  the 
  territory 
  which 
  i- 
  now 
  infested 
  to 
  

   uninfected 
  regions. 
  This 
  is 
  particularly 
  important 
  and 
  is 
  distinctly 
  

  

  of 
  national 
  concern, 
  because 
  goods 
  of 
  this 
  sort 
  are 
  often 
  shipped 
  to 
  

  

  far 
  distant 
  points 
  in 
  the 
  United 
  State-, 
  and 
  without 
  careful 
  scrutiny 
  

   excellent 
  opportunities 
  are 
  offered 
  for 
  establishing 
  new 
  colonies 
  

   remote 
  from 
  the 
  area 
  in 
  New 
  England 
  which 
  is 
  now 
  infested. 
  

  

  (2) 
  Inasmuch 
  a- 
  certain 
  coniferous 
  trees, 
  if 
  grown 
  in 
  solid 
  stands, 
  

   will 
  not 
  furnish 
  favorable 
  food 
  for 
  -mall 
  gipsy-moth 
  caterpillars 
  

   that 
  might 
  he 
  distributed 
  by 
  wind 
  spread, 
  and 
  a- 
  some 
  of 
  our 
  decidu- 
  

  

  