﻿KEYS 
  FOR 
  THE 
  DETERMINATION 
  OF 
  APHIDS. 
  37 
  

  

  26 
  (27). 
  Third 
  joint 
  of 
  antennae 
  in 
  apterous 
  viviparous 
  22 
  almost 
  twice 
  as 
  long 
  as 
  

  

  4th 
  ; 
  hairs 
  on 
  this 
  joint 
  equal 
  to 
  one-quarter 
  to 
  one-third 
  of 
  its 
  diameter 
  ; 
  

   hind 
  tarsus 
  one-third 
  length 
  of 
  tibia 
  ; 
  hind 
  legs 
  three-sevenths 
  length 
  

   of 
  body 
  ; 
  skin 
  spinulose 
  in 
  front 
  half 
  of 
  body 
  ; 
  colour 
  yellow. 
  . 
  

  

  F. 
  polonica, 
  sp. 
  n. 
  

  

  27 
  (26). 
  Third 
  joint 
  of 
  antennae 
  2£-2| 
  times 
  as 
  long 
  as 
  4th 
  ; 
  hairs 
  on 
  antennae 
  

  

  hardly 
  noticeable. 
  

  

  28 
  (29). 
  Tarsi 
  of 
  hind 
  legs 
  one-third 
  to 
  two-fifths 
  length 
  of 
  tibia 
  ; 
  hind 
  legs 
  two- 
  

  

  sevenths 
  to 
  three-tenths 
  length 
  of 
  body 
  ; 
  hairs 
  on 
  legs 
  not 
  noticeable 
  ; 
  

   colour 
  greenish 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  F. 
  pskovensis, 
  sp. 
  n. 
  

  

  29 
  (28). 
  Tarsi 
  of 
  hind 
  legs 
  two-sevenths 
  length 
  of 
  tibia 
  ; 
  hind 
  legs 
  three-eighths 
  

  

  length 
  of 
  body 
  ; 
  hairs 
  on 
  hind 
  tibiae 
  as 
  long 
  as 
  one-quarter 
  to 
  

   three-eighths 
  diameter 
  of 
  tibia 
  ; 
  dark 
  transverse 
  fasciae 
  on 
  7th 
  and 
  

   8th 
  abdominal 
  segments. 
  N. 
  America 
  . 
  . 
  . 
  . 
  F. 
  wilsoni, 
  sp. 
  n. 
  

  

  30 
  (5). 
  Hairs 
  on 
  body 
  and 
  extremities 
  of 
  apterous 
  viviparous 
  22 
  squamiform, 
  

  

  arising 
  from 
  brown 
  dots 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  Group 
  Geoicini. 
  

  

  Here 
  belongs 
  one 
  genus, 
  Geoica, 
  Forbes, 
  with 
  the 
  species 
  G. 
  

   squamosa, 
  Forbes. 
  

  

  Tribe 
  Schizoneurea. 
  

  

  1 
  (6). 
  In 
  apterous 
  viviparous 
  2? 
  tarsus 
  fairly 
  distinctly 
  separated 
  from 
  tibia 
  ; 
  

  

  antennae 
  in 
  viviparous 
  22 
  from 
  roots 
  usually 
  5-jointed 
  (in 
  fundatrices 
  

   A- 
  and 
  3-jointed), 
  the 
  longest 
  joint 
  being 
  not 
  the 
  3rd 
  but 
  the 
  4th 
  ; 
  anal 
  

   sternite 
  projecting 
  behind 
  the 
  tergite 
  and 
  bearing 
  on 
  both 
  sides 
  several 
  

   long 
  hairs 
  bent 
  inwards, 
  to 
  which 
  in 
  living 
  Aphids 
  small 
  drops 
  of 
  

   excrement 
  adhere 
  ; 
  in 
  alate 
  viviparous 
  22 
  3rd 
  joint 
  of 
  antennae 
  shorter 
  

   than 
  the 
  last 
  three 
  together 
  ; 
  median 
  vein 
  of 
  front 
  wings 
  simple 
  

  

  Genus 
  Tetraneura, 
  Hart. 
  

   (Amycla, 
  Koch, 
  Pemphigus, 
  Pass., 
  partim). 
  

  

  2 
  (5). 
  In 
  apterous 
  viviparous 
  22 
  with 
  5-jointed 
  antennae, 
  the 
  last 
  three 
  joints 
  

  

  almost 
  equal 
  in 
  length 
  or 
  else 
  the 
  4th 
  longer 
  than 
  the 
  others 
  ; 
  sometimes 
  

   antennae 
  6-jointed 
  ; 
  in 
  alate 
  viviparous 
  22 
  3rd 
  joint 
  distinctly 
  shorter 
  

   than 
  the 
  three 
  apical 
  ones 
  together. 
  

  

  3 
  (4). 
  In 
  apterous 
  viviparous 
  22 
  with 
  5-jointed 
  antennae, 
  4th 
  joint 
  the 
  longest, 
  

  

  3rd 
  and 
  5th 
  almost 
  equal 
  in 
  length, 
  or 
  else 
  3rd 
  slightly 
  longer 
  than 
  5th 
  ; 
  

   in 
  individuals 
  with 
  6-jointed 
  antennae 
  (which 
  arise 
  in 
  consequence 
  

   of 
  the 
  division 
  of 
  the 
  3rd 
  joint 
  into 
  two) 
  first 
  three 
  joints 
  more 
  or 
  less 
  

   of 
  equal 
  length, 
  4th 
  the 
  shortest, 
  and 
  5th 
  the 
  longest, 
  6th 
  about 
  five- 
  

   ninths 
  of 
  5th 
  ; 
  at 
  sides 
  of 
  body 
  hairs 
  very 
  small, 
  hardly 
  visible, 
  only 
  

   on 
  abdominal 
  segments 
  6-8 
  do 
  they 
  reach 
  0-024-0 
  -060 
  mm. 
  ; 
  anal 
  

   tergite 
  short 
  and 
  covering 
  only 
  a 
  small 
  portion 
  of 
  the 
  sternite 
  ; 
  on 
  

   both 
  sides 
  of 
  anal 
  sternite 
  three 
  long 
  hairs, 
  0-11-0- 
  13 
  mm. 
  long 
  ; 
  in 
  

   alate 
  sexuparae 
  3rd 
  joint 
  of 
  antennae 
  lf-H 
  times 
  as 
  long 
  as 
  5th, 
  

   5th 
  almost 
  twice 
  as 
  long 
  as 
  6th, 
  which 
  is 
  almost 
  equal 
  to 
  4th. 
  . 
  

  

  T. 
  ulmi, 
  DeGeer 
  (Amycla 
  fitscifrons, 
  Koch, 
  Pemph. 
  zeae-maydis, 
  

   Duf., 
  boyeri, 
  Pass., 
  cacridcscens, 
  Mordv., 
  Tetr. 
  setariae, 
  Guerc, 
  

   Byrsocrypta 
  graminis, 
  Schout., 
  Tetr. 
  ithiiisacculi, 
  Patch, 
  T. 
  yezoensis, 
  

   Matsumura, 
  1917). 
  

  

  4 
  (3). 
  In 
  apterous 
  viviparous 
  2? 
  with 
  5-jointed 
  antennae, 
  the 
  last 
  three 
  joints 
  

  

  almost 
  equal 
  to 
  each 
  other 
  ; 
  or 
  even 
  4th 
  somewhat 
  shorter 
  than 
  5th 
  ; 
  

   at 
  sides 
  of 
  body 
  hairs 
  fairly 
  long, 
  measuring 
  0- 
  106-0-10 
  mm. 
  on 
  7th 
  

   and 
  8th 
  abdominal 
  segments 
  ; 
  anal 
  sternite 
  strongly 
  projecting 
  back- 
  

   wards 
  and 
  with 
  only 
  two 
  inwardly 
  bent 
  hairs 
  on 
  each 
  side, 
  measuring 
  

  

  