﻿PACKAIID.] 
  

  

  THE 
  GRAPE 
  PHYLLOXERA. 
  

  

  783. 
  

  

  except 
  in 
  Connecticut, 
  where 
  it 
  has 
  been 
  found 
  by 
  Mr. 
  Riley. 
  I 
  received 
  

   it 
  several 
  years 
  ago 
  from 
  Philadelphia, 
  and 
  it 
  has 
  done 
  much 
  damage 
  

   in 
  the 
  Middle 
  and 
  Western 
  States, 
  while 
  it 
  is 
  known 
  to 
  affect 
  vines 
  in 
  

   California. 
  As 
  we 
  are 
  destined 
  to 
  be 
  greatly 
  annoyed 
  by 
  it, 
  a 
  brief 
  

   description 
  condensed 
  from 
  the 
  excellent 
  account 
  by 
  Mr. 
  Eiley 
  in 
  his 
  

   sixth, 
  seventh, 
  and 
  eighth 
  report 
  of 
  the 
  insect 
  in 
  its 
  two 
  forms, 
  may 
  be 
  

   timely. 
  The 
  insect 
  was 
  first 
  found 
  in 
  this 
  country, 
  and 
  was 
  described 
  

   by 
  Dr. 
  Fitch 
  in 
  1856, 
  under 
  the 
  name 
  of 
  Pemphigus 
  vitifoUw. 
  Its 
  proper 
  

   name 
  is 
  Phylloxera 
  vitifoUce, 
  though 
  most 
  authors 
  speak 
  of 
  it 
  as 
  Phyl- 
  

   loxera 
  vastatrix. 
  It 
  exists 
  in 
  two 
  forms, 
  one 
  raising 
  irregular 
  galls 
  on 
  

   the 
  leaves, 
  and 
  the 
  other 
  forming 
  small 
  swellings 
  on 
  the 
  rootlets. 
  The 
  

   root-form 
  is 
  both 
  wingless 
  and 
  winged, 
  the 
  latter 
  very 
  rare. 
  The 
  leaf- 
  

   form 
  is 
  said 
  to 
  be 
  always 
  wingless. 
  

  

  The 
  wingless 
  female 
  of 
  the 
  leaf-form 
  lays, 
  on 
  an 
  average, 
  200 
  eggs, 
  

   and 
  sometimes 
  500. 
  There 
  are 
  perhaps 
  five 
  generations 
  in 
  a 
  year. 
  This 
  

   leaf-form 
  i^roduces 
  round, 
  irregular 
  galls, 
  sometimes 
  as 
  large 
  as 
  a 
  pea, 
  

   but 
  it 
  does 
  little 
  damage 
  compared 
  with 
  the 
  root-form, 
  which 
  is 
  much 
  

   more 
  abundant 
  than 
  the 
  leaf-form 
  (especially 
  on 
  native 
  vines) 
  in 
  France, 
  

   where 
  its 
  ravages 
  have 
  been 
  so 
  alarming 
  that 
  the 
  French 
  government 
  

   have 
  offered 
  a 
  reward 
  of 
  300,000 
  francs 
  for 
  a 
  simple 
  available 
  remedy. 
  

   The 
  leaf-form 
  descends 
  to 
  the 
  roots 
  in 
  the 
  autumn, 
  and 
  there 
  hyber- 
  

   nates. 
  The 
  larvse 
  of 
  the 
  root-form 
  are 
  at 
  first 
  smooth 
  and 
  like 
  the 
  

   young 
  of 
  the 
  leaf-form, 
  but 
  afterward 
  molt 
  and 
  become 
  warty, 
  so 
  as 
  

   to 
  become 
  readily 
  distinguishable 
  from 
  them. 
  

  

  Professor 
  Eiley 
  and 
  certain 
  French 
  observers 
  have 
  lately 
  proved 
  that 
  

   the 
  gall-producers 
  (or 
  the 
  leaf-form) 
  come 
  from 
  the 
  impregnated 
  or 
  

   winter 
  egg. 
  

  

  The 
  winged 
  females 
  begin 
  to 
  appear 
  in 
  July, 
  but 
  are 
  most 
  abundant 
  

   in 
  August 
  and 
  September. 
  Like 
  the 
  wingless 
  females, 
  they 
  reproduce 
  

   by 
  budding 
  (parthenogenesis), 
  the 
  eggs 
  not 
  being 
  fertilized 
  by 
  males, 
  

   no 
  males 
  being 
  in 
  existence. 
  Having 
  ij^ue^ 
  fCQffi 
  th§ 
  g^Qand 
  whije 
  in 
  

   the 
  pupa 
  state, 
  they 
  rise 
  in 
  . 
  ^ 
  _ 
  .. 
  

  

  the 
  air, 
  and 
  spread 
  to 
  new 
  

   vineyards, 
  where 
  they 
  lay 
  

   twoorthree,sometimeseight 
  

   eggs. 
  These 
  eggs 
  are 
  of 
  two 
  

   sizes, 
  and, 
  in 
  about 
  a 
  fort- 
  

   night, 
  from 
  the 
  larger 
  eggs 
  

   are 
  hatched 
  wingless 
  true 
  

   sexual 
  females, 
  and 
  from 
  the 
  

   smaller 
  eggs 
  wingless 
  males. 
  

   "The 
  abdomen 
  of 
  the 
  fe- 
  

   male, 
  after 
  impregnation, 
  en- 
  

   larges 
  somewliat, 
  and 
  she 
  is 
  

   soon 
  delivered 
  of 
  a 
  solitary 
  

   egg, 
  which 
  differs 
  from 
  the 
  

   ordinary 
  eggs 
  of 
  the 
  parthe- 
  

   nogenetic 
  mother, 
  only 
  in 
  

  

  becoming 
  somewhat 
  darker. 
  Fig. 
  50.— 
  Type 
  gallwcola. 
  a, 
  d, 
  newly-hatched 
  

  

  egg 
  : 
  d, 
  section 
  

  

  larva, 
  ventral 
  and 
  dorsal 
  view 
  

   of 
  gall 
  ; 
  e, 
  swelling 
  of 
  tendril 
  ; 
  /, 
  g, 
  zr, 
  mother 
  gall- 
  

   louse, 
  lateral, 
  dorsal, 
  and 
  ventral 
  views 
  ; 
  i, 
  her 
  

   antenna 
  ; 
  _;, 
  her 
  two-jointed 
  tarsus. 
  Tho 
  figure 
  

   on 
  the 
  side 
  of 
  each 
  enlarged 
  drawing 
  represents 
  

   the 
  natural 
  size. 
  (After 
  Eiley.) 
  

  

  This 
  impregnated 
  egg 
  gives 
  

   birth 
  to 
  a 
  young 
  louse, 
  which 
  

   becomes 
  a 
  virginal, 
  egg-bear- 
  

   ing, 
  wingless 
  mother, 
  and 
  

   thus 
  recommences 
  the 
  cycle 
  

   of 
  the 
  species' 
  evolution. 
  But 
  one 
  of 
  the 
  most 
  important 
  discoveries 
  of 
  

   Balbiani 
  is 
  that, 
  during 
  the 
  latter 
  part 
  of 
  the 
  season, 
  many 
  of 
  the 
  wing- 
  

  

  