CATCH THE BUZZ – Hundreds and Hundreds of Bumble and Other Bees Killed on Linden Trees in Virginia.

There was a Linden tree associated kill event in Reston, VA this week. Table below documents the species involved (Sam Droge did all the identifications)

           Queen Worker Male Female Unknown  Total 
Bombus bimaculatus 21 160 100     281
Bombus impatiens 26 134       160
Bombus griseocolis 5 62 47     114
Bombus perplexus 28 521 40     589
Bombus unkown          25 25
Xylocopa virginica      23 42   23
Apis mellifera   6   1   7
Megachile mendica       10   10
Megachile gemula       1   1
Andrena vicina        11   11
Andrena pruni       1   1
Andrena perplexa       5   5
Andrena barbara       6   6
Andrena species        2   2
Eucera rosae        1   1
Total  80 883 210 38 25 1278

Here is what is known:

  • 3 trees involved
  • Tilia cordata (note:  this species is not associated with Linden poisonings in Europe)
  • Trees were in parking area of a residential area of Reston, Virginia
  • At least 2 trees with noticeable soil injection points
  • Management company said they were treated in March and had been treated every year for about 6 years
  • Unclear what chemicals were involved or whether treatments changed or whether more trees were treated elsewhere
  • Company was advised by their lawyers to no longer speak to anyone
  • 3 people reported the kill but no kill was reported in previous years
  • Most of these bees were picked up on one day
  • 500 or so were picked up by State of Virginia for analysis and not available for species determination
  • Management company would not allow additional collections
  • Trees were not netted after kills were known
  • Note that only 6 Apis were found…despite much greater activity …likely they took nectar back to hives, not clear if there was honey bee mortality at the hives
  • A chemical assay of bees and flowers will be made by the state
  • Pattern is very similar to those of Oregon Linden mortality events…and seems likely to involve neonic treatment

Officials are looking at follow up studies to see if mortality continues in subsequent years pending permissions

 Note that the kill documented here is only part of the total kill

  • Birds were actively eating the dead and dying bees
  • Bees could have flown off and died
  • Small bees were not found…but were likely present
  • Mostly bees were collected from only 1 day, the tree would have been blooming several additional days