﻿25 
  

  

  MORDVILKO'S 
  KEYS 
  FOR 
  THE 
  DETERMINATION 
  OF 
  APHIDS 
  LIVING 
  

   CONTINUOUSLY 
  OR 
  TEMPORARILY 
  ON 
  GRAMINACEOUS 
  PLANTS 
  AND 
  

  

  SEDGES. 
  

  

  [The 
  systematic 
  keys 
  to 
  the 
  species 
  of 
  Aphids 
  that 
  attack 
  Graminaceae, 
  recently 
  

   published 
  by 
  Mr. 
  A. 
  K. 
  Mordvilko 
  (Bull. 
  Petrograd 
  Div. 
  Sta. 
  Protect. 
  Plants 
  from 
  

   Pests, 
  iii, 
  no. 
  3, 
  1921, 
  72 
  pp., 
  19 
  figs.) 
  are 
  likely 
  to 
  be 
  of 
  considerable 
  value 
  to 
  students 
  

   of 
  these 
  injurious 
  insects, 
  and 
  it 
  seemed 
  desirable 
  that 
  they 
  should 
  be 
  translated 
  

   from 
  Russian 
  into 
  English. 
  The 
  original 
  keys 
  are 
  very 
  lengthy, 
  and 
  therefore 
  Mr. 
  

   B. 
  P. 
  Uvarov 
  has 
  kindly 
  condensed 
  them, 
  and 
  they 
  have 
  then 
  been 
  translated, 
  under 
  

   his 
  supervision, 
  by 
  Miss 
  F. 
  B. 
  Constable, 
  of 
  the 
  Imperial 
  Bureau 
  of 
  Entomology. 
  

   Mr. 
  F. 
  Laing, 
  of 
  the 
  British 
  Museum, 
  has 
  also 
  kindly 
  assisted 
  with 
  advice 
  in 
  regard 
  

   to 
  certain 
  technical 
  points. 
  — 
  Ed.] 
  

  

  A. 
  Subfamilies 
  and 
  Tribes. 
  

  

  1 
  (4). 
  Spur 
  of 
  last 
  joint 
  of 
  antennae 
  more 
  or 
  less 
  elongate, 
  either 
  considerably 
  

  

  longer 
  than 
  its 
  base, 
  or 
  if 
  shorter, 
  then 
  only 
  very 
  slightly 
  so 
  

  

  Subfam. 
  Aphidinae 
  (part). 
  

  

  2 
  (3). 
  Cauda 
  sword-shaped, 
  elongate 
  or 
  short-triangular 
  ; 
  cornicles 
  cylindrical 
  

  

  or 
  almost 
  cylindrical, 
  sometimes 
  dilated 
  in 
  the 
  middle 
  or 
  in 
  the 
  distal 
  

   half 
  ; 
  6 
  or 
  7 
  abdominal 
  segments, 
  but 
  in 
  apterous 
  individuals 
  the 
  

   meso- 
  and 
  meta-thorax 
  merge 
  more 
  or 
  less 
  into 
  the 
  abdominal 
  segments 
  

  

  Tribe 
  Aphidea 
  (p. 
  26). 
  

  

  3 
  (2). 
  Cauda 
  club- 
  or 
  wart-shaped, 
  sometimes 
  hemispherical 
  or 
  not 
  pronounced 
  

  

  (anal 
  tergite 
  semicircular), 
  but 
  in 
  this 
  case 
  the 
  body 
  is 
  covered 
  with 
  

   stiff 
  hairs 
  ; 
  segments 
  of 
  body 
  of 
  apterous 
  individuals, 
  especially 
  3rd 
  

   thoracic 
  and 
  1st 
  abdominal, 
  more 
  or 
  less 
  distinct 
  ; 
  cornicles 
  generally 
  

   very 
  short, 
  but 
  fairly 
  thick, 
  somewhat 
  widening 
  towards 
  base 
  and 
  

   tube-shaped 
  towards 
  the 
  top, 
  sometimes 
  truncate, 
  conical 
  or 
  nearly 
  

   dome-shaped 
  ; 
  last 
  joint 
  of 
  rostrum 
  without 
  a 
  subapical 
  constriction 
  

  

  Tribe 
  Callipterea 
  (p. 
  31). 
  

  

  4 
  (1). 
  Spur 
  of 
  last 
  joint 
  of 
  antennae 
  considerably 
  shorter 
  than 
  its 
  base, 
  generally 
  

  

  only 
  in 
  the 
  form 
  of 
  a 
  short 
  pointed 
  process 
  ; 
  antennae 
  seldom 
  longer 
  

   than 
  head 
  with 
  thorax, 
  often 
  considerably 
  shorter. 
  

  

  5 
  (8). 
  Last 
  joint 
  of 
  rostrum 
  with 
  a 
  distinct 
  subapical 
  constriction, 
  as 
  though 
  

  

  with 
  an 
  additional 
  5th 
  joint 
  (at 
  end 
  of 
  proximal 
  division 
  of 
  last 
  joint, 
  

   are 
  two 
  fairly 
  noticeable 
  lateral 
  hairs) 
  . 
  . 
  Subfam. 
  Lachninae 
  

  

  6 
  (7). 
  Sides 
  of 
  prothorax 
  and 
  abdominal 
  segments 
  1-5 
  and 
  7 
  with 
  fairly 
  distinct^ 
  

  

  broad, 
  flatly 
  convex, 
  light, 
  glandular 
  tubercles, 
  joining 
  with 
  dark 
  

   marginal 
  plates, 
  especially 
  developed 
  on 
  the 
  prothorax 
  and 
  1st 
  and 
  

   7th 
  abdominal 
  segments 
  . 
  . 
  . 
  . 
  . 
  . 
  Tribe 
  Anoeciea 
  (p. 
  34). 
  

  

  7 
  (6). 
  Sides 
  of 
  prothorax 
  and 
  abdomen 
  without 
  glandular 
  tubercles 
  

  

  Tribe 
  Lachnea.* 
  

  

  8 
  (5). 
  Last 
  joint 
  of 
  rostrum 
  simple, 
  without 
  a 
  subapical 
  constriction 
  ; 
  legs 
  short, 
  

  

  not 
  visible 
  when 
  the 
  strongly 
  inflated, 
  ovate 
  or 
  nearly 
  spherical 
  body 
  

   is 
  viewed 
  from 
  above 
  ; 
  tarsi 
  short, 
  generally 
  with 
  two 
  joints, 
  rarely 
  

   with 
  one, 
  or 
  even 
  not 
  separated 
  from 
  the 
  tibia 
  

  

  Subfam. 
  Pemphiginae. 
  

  

  * 
  Aphids 
  of 
  this 
  tribe 
  are 
  not 
  yet 
  known 
  on 
  graminaceous 
  plants. 
  

  

  