﻿The 
  British 
  Species 
  of 
  Andrena 
  and 
  Nomada. 
  221 
  

  

  still 
  more 
  in 
  advance, 
  and, 
  as 
  has 
  been 
  said, 
  last 
  for 
  a 
  much 
  

   shorter 
  period. 
  Isolated 
  cases 
  of 
  a 
  female 
  captured 
  before 
  a 
  

   male 
  has 
  been 
  seen 
  are 
  not 
  to 
  be 
  considered 
  as 
  anything 
  but 
  

   abnormal 
  exceptions, 
  the 
  aggregate 
  of 
  the 
  latter 
  sex 
  always 
  

   preceding 
  the 
  other. 
  Sandy, 
  gravelly 
  or 
  light 
  soils 
  are 
  

   absolute 
  requirements 
  of 
  some 
  species, 
  and 
  they 
  need 
  not 
  

   be 
  looked 
  for 
  where 
  these 
  do 
  not 
  occur. 
  Rich 
  meadowland 
  

   is 
  greatly 
  inferior 
  as 
  a 
  collecting 
  ground 
  to 
  sandy 
  heaths, 
  

   waste 
  places 
  and 
  coast 
  land. 
  Certain 
  species, 
  however, 
  

   such 
  as 
  A. 
  albicans, 
  nigroaenea 
  and 
  wilkella 
  seem 
  to 
  flourish 
  

   equally 
  in 
  almost 
  all 
  situations 
  in 
  the 
  South 
  of 
  England. 
  

  

  The 
  welfare 
  of 
  our 
  wild 
  bees 
  and 
  wasps 
  is 
  probably 
  more 
  

   dependent 
  on 
  weather 
  conditions 
  than 
  is 
  that 
  of 
  any 
  other 
  

   group 
  of 
  insects. 
  Most 
  of 
  their 
  species 
  never 
  venture 
  from 
  

   their 
  burrows 
  unless 
  the 
  sun 
  is 
  bright, 
  though 
  some 
  will 
  do 
  

   so 
  on 
  sultry 
  days, 
  even 
  though 
  the 
  sky 
  is 
  overcast. 
  In 
  

   early 
  spring 
  some 
  species 
  of 
  Andrena 
  are 
  active 
  enough, 
  

   even 
  though 
  the 
  temperature 
  is 
  low, 
  provided 
  that 
  the 
  sun 
  

   is 
  bright. 
  A 
  thoroughly 
  wet 
  and 
  cold 
  season 
  is 
  very 
  disas- 
  

   trous. 
  Of 
  those 
  that 
  I 
  have 
  spent 
  in 
  England 
  since 
  I 
  began 
  

   to 
  collect 
  our 
  Aculeates, 
  the 
  year 
  1888 
  was 
  the 
  most 
  remark- 
  

   able. 
  The 
  preceding 
  season 
  was 
  a 
  favourable 
  one 
  in 
  North 
  

   Wiltshire, 
  and 
  during 
  the 
  autumn 
  the 
  species 
  of 
  such 
  genera 
  

   as 
  Halichis 
  and 
  Sphecodes 
  had 
  in 
  all 
  probability 
  reached 
  

   their 
  maximum 
  abundance. 
  The 
  hibernated 
  females 
  of 
  

   these, 
  of 
  course, 
  appeared 
  in 
  the 
  following 
  spring, 
  but 
  the 
  

   new 
  generation 
  was 
  almost 
  wanting. 
  Only 
  a 
  few 
  males 
  of 
  

   the 
  most 
  abundant 
  species 
  began 
  to 
  appear 
  in 
  August, 
  

   about 
  a 
  month 
  late 
  — 
  and 
  four 
  of 
  the 
  commonest 
  Sphecodes 
  

   could 
  not 
  be 
  found 
  at 
  all. 
  Andrena 
  nigroaenea 
  was 
  still 
  

   endeavouring 
  to 
  collect 
  pollen 
  at 
  the 
  end 
  of 
  August, 
  and 
  A. 
  

   wilkella 
  far 
  into 
  September. 
  The 
  first 
  males 
  of 
  Halictus 
  

   nitidiusculus 
  and 
  H. 
  xanthopus 
  appeared 
  on 
  Sept. 
  20th, 
  

   while 
  on 
  Oct. 
  5th 
  nearly 
  every 
  garden 
  flower 
  was 
  cut 
  down 
  

   by 
  the 
  severe 
  frosts. 
  A 
  colony 
  of 
  the 
  last 
  named, 
  thousands 
  

   strong, 
  was 
  entirely 
  destroyed 
  and 
  never 
  reappeared. 
  

   Sudden 
  storms, 
  especially 
  hail-storms, 
  that 
  occur 
  when 
  the 
  

   season 
  is 
  well 
  advanced 
  are 
  very 
  disastrous. 
  Being 
  aware 
  

   of 
  a 
  spot 
  where 
  A. 
  proxima 
  occurred, 
  I 
  started 
  one 
  day 
  at 
  

   the 
  beginning 
  of 
  June 
  in 
  bright 
  sunshine 
  to 
  the 
  locaUty. 
  

   On 
  reaching 
  the 
  place 
  males 
  were 
  at 
  once 
  noticed 
  flying 
  

   about 
  the 
  bushes, 
  and 
  females 
  gathering 
  pollen 
  from 
  the 
  

   flowers 
  of 
  a 
  white 
  Umbellifer. 
  Just 
  then 
  it 
  clouded 
  over 
  

   and 
  hail 
  began 
  to 
  fall. 
  A 
  few 
  of 
  the 
  bees 
  were 
  picked 
  up 
  in 
  

  

  