﻿110 
  

  

  EXPLANATION 
  OF 
  PLATES.^ 
  

  

  Plate 
  I. 
  

  

  Map 
  of 
  Illinois, 
  showing 
  known 
  distribution 
  of 
  San 
  Jose 
  Scale 
  in 
  

   Illinois 
  (October. 
  1897 
  ). 
  Red 
  dots 
  indicate 
  infested 
  localities 
  (See 
  

  

  p. 
  8). 
  

  

  Plate 
  II. 
  f 
  

  

  Fig. 
  1. 
  Appearance 
  of 
  San 
  Jose 
  Scale 
  on 
  bark: 
  a, 
  infested 
  twig, 
  

   natural 
  size; 
  h, 
  bark 
  as 
  it 
  appears 
  under 
  hand 
  lens, 
  show- 
  

   ing 
  scales 
  in 
  various 
  stages 
  of 
  development 
  and 
  young 
  

   larvie. 
  

  

  F'ig. 
  2. 
  San 
  Jose 
  Scale: 
  «, 
  pear, 
  moderately 
  infested 
  — 
  natural 
  size; 
  

   6, 
  female 
  scale 
  — 
  enlarged. 
  (Sec 
  pp. 
  2 
  and 
  15.) 
  

  

  Plate 
  IILJ 
  

  

  Fig. 
  1. 
  San 
  Jose 
  Scale, 
  adult 
  female, 
  before 
  development 
  of 
  eggs: 
  

   a, 
  ventral 
  view, 
  showing 
  very 
  long 
  sucking 
  setae; 
  6, 
  pos- 
  

   terior 
  extremity, 
  showing 
  characteristic 
  ornamentation 
  of 
  

   edge. 
  Greatly 
  enlarged. 
  

  

  Fig. 
  2. 
  Young 
  larva 
  and 
  developing 
  scale: 
  a. 
  ventral 
  view 
  of 
  larva, 
  

   showing 
  sucking 
  beak 
  with 
  set;e 
  separated, 
  with 
  enlarged 
  

   tarsal 
  claw 
  at 
  right; 
  />, 
  dorsal 
  view 
  of 
  same, 
  somewhat 
  con- 
  

   tracted, 
  with 
  the 
  first 
  waxy 
  filaments 
  appearing; 
  c, 
  dorsal 
  

   and 
  lateral 
  views 
  of 
  same, 
  still 
  more 
  contracted, 
  illustrat- 
  

   ing 
  further 
  development 
  of 
  wax 
  secretion; 
  d, 
  later 
  stage 
  

   of 
  same, 
  dorsal 
  and 
  lateral 
  views, 
  showing 
  matting 
  of 
  wax 
  

   secretions 
  and 
  first 
  form 
  of 
  young 
  scale. 
  All 
  greatly 
  en- 
  

   larged. 
  

  

  * 
  PI. 
  v.. 
  PI. 
  VL, 
  Fig. 
  2, 
  PI. 
  VII.. 
  and 
  Pis. 
  VIII. 
  to 
  X. 
  are 
  from 
  dniwings 
  made 
  by 
  Miss 
  

   Lydia 
  M. 
  Hart, 
  artist 
  to 
  the 
  iState 
  Laboratory; 
  PI. 
  VI., 
  Fig. 
  1. 
  is 
  from 
  a 
  photograph. 
  

   t 
  From 
  Bull. 
  No. 
  3. 
  N. 
  S., 
  and 
  from 
  Circular 
  No. 
  3, 
  U. 
  S. 
  Dept. 
  Agr., 
  Div. 
  of 
  Ent. 
  

   -t 
  From 
  Bull. 
  No. 
  3, 
  N. 
  S., 
  U. 
  S. 
  Dept. 
  Agr. 
  

  

  