We have a large garden in Bedfordshire, UK, next to woods and to arable fields currently planted with intensively farmed rape. We usually have many bees in the garden. Earlier this year, things were humming along as usual. A cotoneaster bush in flower had perhaps a hundred bees on it at once, of at least 6 different species.
Now, in July, we have lavender and clover in full bloom, normally swarming with bees. But, not now. This morning (overcast and warm) there were two bees on a lavender bush covering two square metres. I can walk for minutes in the garden without seeing a single bee. The leafcutter bees have left no holes in our rose leaves this year.
The nearest managed hives are about 800m away. It's not just a managed hive that has gone, the bumblebees that nest in our garden have gone too.
The rape flowers are long past. I don't know what might have been sprayed on the rape. Our garden is organic.
Wasps are down too. This is the first year in the last twenty that there are no wasp nests in our outbuildings. There are, however, plenty of flies.
What might have caused such a sudden and unusual population change? Among multiple species of bee from multiple sources, between April and July?
Could it be our globally-warmed weather? June and July have been wetter and warmer than usual, although not exceptionally so.
Are UK farmers allowed to use an insecticide on rape that could kill most bees?
Or is a dramatic in-year population change in bees a routine, if uncommon, event?
Update August 17 2016
Our garden bees do seem to be gradually recovering - nothing like most years, but a few bees are coming back. Other nearby houses, at least 400m from the nearest rape field, have plenty of bees.