﻿527 
  

  

  Russell 
  (H. 
  M.). 
  The 
  Rose 
  Aphis. 
  — 
  U.S. 
  Dept. 
  Agnc, 
  Washington, 
  

   D.C., 
  Bull. 
  no. 
  90, 
  May 
  1914, 
  15 
  pp., 
  4 
  figs., 
  3 
  pis. 
  

  

  In 
  this 
  paper 
  the 
  author 
  deals 
  with 
  the 
  rose 
  aphis, 
  Macrosiphum 
  rosae, 
  

   L,, 
  as 
  observed 
  near 
  Los 
  Angeles, 
  Cal., 
  and 
  at 
  Washington, 
  D.C. 
  A 
  

   description, 
  with 
  illustrations, 
  is 
  given 
  of 
  the 
  various 
  stages 
  and 
  of 
  the 
  

   habits. 
  In 
  the 
  climate 
  of 
  southern 
  CaUfornia 
  reproduction 
  occurs 
  

   throughout 
  the 
  year 
  and 
  eggs 
  were 
  not 
  observed. 
  At 
  Washington, 
  the 
  

   author 
  found 
  a 
  few 
  eggs 
  on 
  the 
  sides 
  of 
  dormant 
  buds 
  of 
  rose- 
  

   bushes 
  on 
  29th 
  November 
  1912. 
  The 
  rose 
  aphis 
  increases 
  very 
  rapidly 
  

   during 
  the 
  autumn 
  and 
  spring, 
  but 
  during 
  the 
  summer 
  the 
  increase 
  

   is 
  less 
  rapid 
  and 
  natural 
  enemies 
  keep 
  it 
  in 
  check 
  ; 
  in 
  the 
  winter 
  

   development 
  is 
  slower 
  and 
  reproduction 
  less. 
  From 
  October 
  1909 
  

   to 
  10th 
  March 
  1910, 
  the 
  author 
  carried 
  out 
  experiments 
  under 
  normal 
  

   conditions 
  in 
  South 
  CaUfornia, 
  from 
  which 
  he 
  concludes 
  that 
  during 
  

   winter 
  the 
  rose 
  aphis 
  may 
  give 
  birth 
  to 
  45 
  young 
  over 
  a 
  period 
  of 
  20 
  

   days, 
  while 
  in 
  the 
  summer 
  the 
  period 
  is 
  probably 
  shorter 
  and 
  the 
  

   number 
  of 
  offspring 
  greater, 
  the 
  maximum 
  length 
  of 
  the 
  Ufe-cycle 
  being 
  

   approximately 
  18 
  days 
  for 
  apterous 
  and 
  25 
  days 
  for 
  alate 
  females 
  

   in 
  November. 
  During 
  the 
  autumn 
  of 
  1912, 
  from 
  observations 
  in 
  the 
  

   insectary 
  greenhouse 
  at 
  Washington, 
  at 
  an 
  average 
  mean 
  tem- 
  

   perature 
  of 
  67° 
  F., 
  the 
  period 
  of 
  development 
  was 
  shortened 
  and 
  the 
  

   number 
  of 
  young 
  increased. 
  With 
  a 
  life-cycle 
  of 
  25 
  days 
  there 
  would 
  

   be 
  more 
  than 
  12 
  generations 
  in 
  the 
  year, 
  and 
  7 
  or 
  8 
  generations 
  more 
  

   in 
  the 
  warmer 
  weather. 
  

  

  The 
  author 
  observed 
  a 
  white-crowned 
  sparrow 
  {Zonotrichia 
  leucophrys) 
  

   and 
  on 
  another 
  occasion 
  a 
  California 
  house 
  finch 
  [Carpodacus 
  mexicanus 
  

   frontalis) 
  destroying 
  large 
  numbers 
  of 
  this 
  aphid. 
  An 
  undetermined 
  

   insect 
  parasite 
  of 
  Macrosiphum 
  rosae 
  was 
  found 
  on 
  13th 
  June 
  1910, 
  the 
  

   full-grown 
  larvae 
  having 
  spun 
  cocoons 
  between 
  the 
  dead 
  body 
  of 
  the 
  

   host 
  and 
  the 
  leaf 
  ; 
  the 
  imagos 
  did 
  not 
  emerge. 
  The 
  author 
  bred 
  a 
  

   Braconid, 
  Ephedrus 
  incompletus, 
  Prov., 
  from 
  M. 
  rosae 
  at 
  Washington, 
  

   in 
  1912. 
  Five 
  different 
  species 
  of 
  Syrphidae, 
  some 
  of 
  which 
  

   are 
  figured, 
  were 
  reared 
  in 
  1910 
  from 
  larvae 
  found 
  feeding 
  on 
  M. 
  rosae, 
  

   namely 
  : 
  Syrphus 
  ribesii, 
  L., 
  S. 
  opinator, 
  O.S., 
  Allograpta 
  fracta, 
  O.S., 
  

   Eupeodes 
  volucris, 
  O.S., 
  and 
  Lasiophthicus 
  pyrasti, 
  L. 
  The 
  adult 
  flies 
  

   were 
  seen 
  to 
  desert 
  the 
  rose-bushes 
  as 
  they 
  became 
  shaded 
  from 
  the 
  

   sun. 
  Small 
  numbers 
  of 
  Hippodamia 
  ambigua, 
  Lee, 
  were 
  seen 
  

   throughout 
  these 
  observations, 
  though 
  they 
  rarely 
  appeared 
  to 
  be 
  

   feeding 
  on 
  the 
  aphids. 
  

  

  In 
  March 
  1913, 
  in 
  a 
  greenhouse 
  at 
  Washington, 
  four 
  badly 
  infested 
  

   bushes 
  were 
  sprayed 
  with 
  a 
  solution 
  made 
  as 
  follows 
  : 
  " 
  Black 
  leaf 
  40 
  " 
  

   J 
  oz., 
  whale-oil 
  soap 
  J 
  lb., 
  water 
  2| 
  gallons. 
  The 
  terminal 
  buds 
  

   and 
  tender 
  shoots 
  were 
  slightly 
  injured, 
  but 
  all 
  the 
  aphids 
  were 
  

   killed 
  ; 
  probably 
  a 
  25 
  per 
  cent, 
  weaker 
  solution 
  could 
  have 
  

   been 
  used 
  with 
  equal 
  success. 
  In 
  another 
  case 
  infested 
  rose- 
  

   bushes, 
  trained 
  against 
  a 
  wall, 
  were 
  successfully 
  sprayed 
  with 
  

   nicotin 
  sulphate, 
  1 
  part 
  in 
  1,000, 
  mixed 
  both 
  with 
  and 
  without 
  

   soap 
  (the 
  former 
  being 
  more 
  efficient). 
  Solutions 
  more 
  dilute 
  than 
  

   1 
  part 
  in 
  1,400 
  of 
  40 
  per 
  cent, 
  nicotin 
  sulphate 
  were 
  unsatisfactory, 
  

   though 
  with 
  the 
  addition 
  of 
  soap 
  they 
  were 
  slightly 
  improved. 
  The 
  

   pressure 
  was 
  estimated 
  at 
  90 
  lb., 
  a 
  compressed 
  air 
  sprayer 
  and 
  Bordeaux 
  

   type 
  of 
  nozzle 
  being 
  used, 
  with 
  a 
  fine 
  driving 
  spray. 
  Whale-oil 
  or 
  

  

  