﻿KEYS 
  FOR 
  THE 
  DETERMINATION 
  OF 
  APHIDS. 
  29 
  

  

  35 
  (34). 
  Cornicles 
  of 
  apterous 
  viviparous 
  $$ 
  only 
  one-fourth 
  longer 
  than 
  cauda; 
  

  

  antennae 
  three-fifths 
  the 
  length 
  of 
  body, 
  the 
  3rd 
  joint 
  exceeding 
  4th 
  

   by 
  one-third 
  to 
  one-quarter 
  ; 
  males 
  apterous. 
  Found 
  as 
  yet 
  only 
  in 
  

  

  the 
  Pskov 
  province, 
  on 
  leaves 
  of 
  Calamogrostis 
  sp 
  

  

  T. 
  jaroslavi, 
  sp. 
  n. 
  

  

  36 
  (33). 
  Colour 
  dark 
  brown 
  ; 
  cornicles 
  black 
  ; 
  cauda 
  brown 
  ; 
  antennae 
  brown, 
  

  

  first 
  two 
  joints 
  black. 
  On 
  Scirpus 
  ; 
  Italy 
  . 
  . 
  T. 
  scirpi, 
  Pass. 
  

  

  37 
  (32). 
  Antennal 
  tubercles 
  inconspicuous 
  ; 
  front 
  between 
  base 
  of 
  antennae 
  broad 
  

  

  and 
  convex, 
  or 
  else 
  from 
  the 
  bottom 
  of 
  the 
  frontal 
  furrow 
  there 
  springs 
  

   a 
  central 
  frontal 
  tubercle, 
  which 
  is 
  scarcely 
  lower 
  than 
  the 
  antennal 
  

   tubercles 
  ; 
  median 
  vein 
  branching 
  twice 
  in 
  alate 
  individuals. 
  

  

  38 
  (58). 
  Cornicles 
  more 
  or 
  less 
  cylindrical, 
  without 
  distinct 
  constriction 
  before 
  

  

  the 
  operculum 
  ; 
  operculum 
  narrower 
  than 
  central 
  portion 
  of 
  cornicle 
  . 
  . 
  

  

  Genus 
  Aphis, 
  L. 
  

  

  39 
  (48). 
  Three 
  stout 
  marginal 
  tubercles 
  : 
  on 
  prothorax, 
  and 
  on 
  1st 
  and 
  7th 
  

  

  abdominal 
  segments 
  ; 
  cornicles 
  more 
  or 
  less 
  exceeding 
  the 
  length 
  of 
  

   cauda. 
  

  

  40 
  (47). 
  Spur 
  of 
  6th 
  joint 
  of 
  antennae 
  at 
  least 
  2£-3 
  times 
  as 
  long 
  as 
  the 
  base 
  of 
  

  

  the 
  same 
  joint, 
  5th 
  joint 
  considerably 
  (one-half 
  to 
  four-fifths) 
  longer 
  

   than 
  base 
  of 
  6th 
  joint 
  

  

  41 
  (42). 
  Spur 
  of 
  6th 
  joint 
  subequal 
  to 
  3rd 
  joint 
  and 
  nearly 
  three 
  times 
  as 
  long 
  as 
  

  

  the 
  base 
  of 
  that 
  joint 
  ; 
  body 
  of 
  apterous 
  viviparous 
  $$ 
  greenish 
  brown, 
  

  

  coffee-brown, 
  or 
  dull 
  black, 
  dusted 
  with 
  black 
  

  

  A. 
  rumicis, 
  L. 
  (= 
  papaveris, 
  F.). 
  

   This 
  species 
  lives 
  on 
  the 
  ends 
  of 
  young 
  shoots 
  and 
  under 
  the 
  

   leaves 
  of 
  the 
  spindle-tree, 
  white 
  hazel 
  tree 
  and 
  jasmine 
  (primary 
  

   hosts), 
  and 
  on 
  many 
  herbs 
  (intermediate 
  hosts) 
  : 
  Rumex, 
  Atriplex, 
  

   Chenopodium, 
  Beta, 
  Rhoeum, 
  Lappa 
  major, 
  Vicia 
  faba 
  and 
  others 
  ; 
  

   of 
  the 
  Graminaceae 
  only 
  on 
  maize. 
  

  

  42 
  (41). 
  Spur 
  of 
  6th 
  joint 
  of 
  antennae 
  1-2 
  times 
  as 
  long 
  as 
  the 
  3rd 
  joint, 
  and 
  

  

  3-6 
  times 
  as 
  long 
  as 
  the 
  base 
  of 
  that 
  joint. 
  

  

  43 
  (44). 
  Body 
  of 
  apterous 
  individuals 
  yellowish 
  or 
  vello 
  wish-green. 
  On 
  Sorghum 
  ; 
  

  

  West 
  Africa 
  (Togo) 
  A. 
  sorghella, 
  Schout. 
  

  

  44 
  (43). 
  Body 
  of 
  apterous 
  individuals 
  brown. 
  

  

  45 
  (46). 
  Body 
  and 
  legs 
  covered 
  with 
  fairly 
  long 
  hairs 
  ; 
  on 
  the 
  segments 
  of 
  the 
  

  

  body 
  (at 
  least 
  in 
  apterous 
  individuals) 
  hairs 
  arranged 
  in 
  transverse 
  

   rows, 
  each 
  hair 
  arising 
  from 
  an 
  elevated 
  base 
  ; 
  spur 
  of 
  6th 
  joint 
  of 
  

   antennae 
  3h-U 
  times 
  as 
  long 
  as 
  the 
  base 
  of 
  that 
  joint 
  and 
  lf-2 
  times 
  

   as 
  long 
  as 
  3rd" 
  joint. 
  On 
  Carex 
  pseudocyperus 
  and 
  others 
  ; 
  Belgium 
  

  

  A. 
  caricis, 
  Schout. 
  

  

  46 
  (45). 
  Body 
  and 
  legs 
  not 
  very 
  hairy 
  ; 
  hairs 
  on 
  body 
  arising 
  from 
  the 
  smooth 
  

  

  surface 
  ; 
  spur 
  of 
  6th 
  joint 
  of 
  antennae 
  5-6 
  times 
  as 
  long 
  as 
  the 
  base 
  

   of 
  that 
  joint, 
  and 
  twice, 
  or 
  nearly 
  twice, 
  the 
  length 
  of 
  3rd 
  joint. 
  On 
  

   Primus 
  maritima 
  and 
  Setaria 
  ; 
  N. 
  America 
  A. 
  setariae, 
  Thomas. 
  

  

  47 
  (40). 
  Spur 
  of 
  6th 
  joint 
  of 
  antennae 
  not 
  more 
  than 
  twice 
  as 
  long 
  as 
  the 
  base 
  of 
  

  

  the 
  same 
  joint 
  ; 
  5th 
  joint 
  subequal 
  to 
  the 
  base 
  of 
  6th 
  or 
  even 
  somewhat 
  

   shorter. 
  N. 
  America 
  ; 
  on 
  roots 
  of 
  Sorghum, 
  Setaria, 
  Panicum, 
  Rumex, 
  

   Polygonum, 
  Portulaca, 
  Brassica 
  nigra, 
  Plantago 
  major, 
  pumpkin 
  and 
  

   others 
  . 
  . 
  • 
  • 
  • 
  • 
  • 
  • 
  . 
  . 
  A. 
  maidi-radicis 
  , 
  Forbes. 
  

  

  48 
  (39). 
  Three 
  pairs 
  of 
  small 
  marginal 
  tubercles: 
  on 
  the 
  prothorax 
  and 
  on 
  

  

  1st 
  and 
  7th 
  segments 
  of 
  abdomen 
  ; 
  body 
  of 
  apterous 
  viviparous 
  $? 
  

   2-'2h 
  times 
  as 
  long 
  as 
  wide. 
  

  

  