Bee  sampling  methods  and  the  differences  between  collec5ng  with  nets  and  bee  bowls  in  northern  

Indiana  

Robert  P.  Jean,  Missouri  Department  of  Conserva8on/Indiana  State  

University  

Why  are  bees  important??  

•  Provide  essen5al  ecological  services  •  Crop  pollina5on  •  Flower  and  tree  pollina5on  •  Important  component  of  the  biodiversity  in  many  areas  

•  Some  researchers  suspect  declines  in  na5ve  bee  popula5ons  (ForgoBen  Pollinators)  

Why  study  bees?  

•  Species  rich  –  good  for  examining  community  complexity,  species  coexistence,  or  compe55on  

•  Easy  to  sample  

•  Can  examine  a  specialist  to  generalist  con5nuum  with  both  parasi5c  and  flower  visi5ng  groups  

•  Rela5vely  intact  na5ve  bee  communi5es  

Where  and  When  to  Collect  Bees  

Where  •  Anywhere  there  are  

flowers  

•  Any  habitat  type  •  LiBle  informa5on  on  

rela5ve  abundances  throughout  species  ranges  

•  LiBle  informa5on  of  bee  species  habitat  specificity  

When  •  Basically  March  15-­‐October  

15  

•  Bees  definitely  seasonal  

How  to  Sample  Bees  

NeTng  at  Flowers  

•  Standardized  on  5me  or  area  or  both  

•  Belt  transect  designs  •  Rambling  fashion  –  collec5ng  at  flower  patches  

•  Sweep  neTng  •  Record  floral  records  

NeTng  at  Flowers  

Pros  •  Detailed  ecological  

informa5on  can  be  collected  

•  Flower  records/Time  of  day  

•  Can  process  bees  immediately  

•  Can  observe  bee  habits  •  Can  examine  pollen  loads  •  Its  fun!!!!  

Cons  •  Requires  neTng  skill  •  Hard  to  standardize  

among  different  collectors  

•  Time  consuming  •  Can  only  sample  a  couple  

sites  a  day  at  different  5mes  

•  Must  carry  poisons  

Bee  Bowl  Trapping  

•  Solo  bowls  painted  flourescent  colors  

•  Filled  with  detergent  water  

•  Passive  sampling  •  BI  Plot  design  

–  2  –  50m  intersec5ng  transects,  15  bowls  each  

•  USGS  sample  design  –  Single  transect  with  15  traps  separated  by  5m  

Pros  and  Cons  of  Bee  bowl  trapping  

Pros  

•  Easy  to  teach  and  employ  

•  Collects  lots  of  individuals  

•  Can  sample  several  sites  simultaneously  

•  Method  easily  standardized  

Cons  

•  Specimens  require  storage  in  alcohol  

•  Processing  specimens  requires  more  steps  

•  No  ecological  data    •  Must  carry  water    •  Difficult  in  tall  grass  and  steep  terrain  

Malaise  traps  

Pros  

•  Can  collect  large  numbers  of  individuals  

Cons  

•  Setup  loca5on  very  important  

•  Expensive  •  Poison  

Trap  Nes5ng  

Cons  

•  Only  collects  wood  nes5ng  bees  

•  Maintenance  and  rearing  

Pros  

•  Easy  to  build  and  deploy  

•  Can  set  up  in  standardized  fashion  

Other  Sampling  Techniques  

•  Chemical  baits  •  UV  Lights  

Effec5ve  Sampling  Techniques  

•  Sample  in  a  standardized  fashion  so  that  collec5on  effort  can  be  measured  

•  Sample  in  different  seasons  –  every  2-­‐4  weeks  

•  Mul5ple  years  –  lots  of  varia5on,  especially  among  rare  species  

•  Combina5on  of  sampling  techniques  •  Accurate  bee  and  host  plant  ID’s  and  labeling  

Bee  bowls  vs.  NeTng  at  flowers  in  Northern  Indiana  

Background  

•  Data  collected  in  2003  •  Four  sites  sampled  simultaneously  

•  Pan  trap  collec5ons  performed  every  2-­‐3  weeks  

•  Net  collec5ons  performed  at  each  site  within  2  days  of  a  pan  collec5on,  but  ofen  2-­‐3  days  more  net  collec5on  at  a  site  in  a  given  month  

Effort  

•  12  days  of  pan  trap  collec5ons  (104-­‐116  hours)  per  site  

•  18-­‐20  days  of  net  collec5ons  per  site  (18-­‐27  hours)  

•  1047-­‐1441  individuals  collected  with  pans  per  site  (5087  total)  

•  365-­‐582  ind  collected  by  net  per  site  (2037  total)  

Species Richness

Rare  Bee  Species  –  Why  do  they  MaBer?  

•  Redundancy  in  pollina5ons  systems  very  important  –  lots  of  varia5on  in  space  and  5me  in  the  abundance  and  species  richness  of  bees.  

•  Bee  species  vary  in  pollina5on  effec5veness  and  efficiency  

•  Defini5on  of  rare…  

Conclusions  

•  There  are  several  techniques  that  can  be  used  to  collect  bees.  

•  Each  collec5on  technique  has  its  pros  and  cons.  •  NeTng  at  flowers  and  bee  bowls  are  the  most  popular  bee  collec5on  methods  because  they  are  cost  effec5ve,  simple,  and  successful.  

•  Both  techniques  collect  different  sets  of  rare  species  which  are  poten5ally  important  for  pollina5on.  

Acknowledgements  

•  Field  Assistance-­‐Michelle  Jean,  Theresa  Dailey,  Josh  Wallace  

•  Advisor-­‐Peter  ScoB  •  ID  assistance-­‐  Mike  Arduser,  Sam  Droege,  John  Ascher  

Species  Richness  Es5mates  

NeTng  at  Flowers  •  Individual  site  SR  es5mates  

ranged  from  83-­‐123  species  using  ACE  and  95-­‐140  species  using  ICE  

•  3  of  4  sites  have  larger  SR  es5mates;  larger  range  of  SR  esimates  for  sites  

•  Combining  the  four  sites:  –  ICE  =  229  species  –  ACE  =  179  species  

Bee  Bowls  •  Individual  site  SR  es5mates  

ranged  from  93-­‐111  species  using  ACE  and  120-­‐136  species  using  ICE  

•  Only  one  site  with  larger  SR  es5mate;  narrower  range  of  predicted  SR  es5mates  

•  Combining  the  four  sites  –  ICE  =  176  species  –  ACE  =  150  species