Tree Bumblebee - image from Entomart.be
Bees are great for our gardens - and mostly, whether solitary or communal, work best on their own. But what happens when we decide to or are required to intervene?
In my February blog, I told you that there are arguably 29 bumblebee species in the UK. The most recent arrival is actually a reintroduction. The numbers of short-haired bumblebees (bombus subterraneus) had been in decline since the 1950s and it was last seen near Dungeness in 1988. By 2000 it was declared extinct in the UK. Its disappearance was blamed on the loss of habitat. The RSPB got together with Natural England, Hymettus and the Bumblebee Conservation Trust and hatched a plan to bring some queen bees back from New Zealand, where some British short-haired bumblebees had been taken in the 1890s to pollinate red clover.
We just have to do it, we humans? We can’t leave anything alone. This didn’t pan out as the Kiwi bees were all too inbred, but the experts didn't stop. They realised that the largest population of these bees was actually in Sweden and so, in 2012, they released 51 queen short-haired bumblebees into the wild on an RSPB reserve near to the last place they had been seen, near Dungeness. The following year they released a further 49 queens and the position is being closely monitored.
When Swedish scientist Bjorn Cederberg announced that he had allowed 100 short-haired bumblebees to be collected and shipped to England, he received death threats. Bumblebees appear to be an emotive subject in Sweden.
The Tree Bumblebee
The somewhat savvier Tree Bumblebee (Bombus hypnorum) managed to get here unaided. This very ginger and black bee suddenly appeared in Wiltshire during 2001. Since then it has spread like wildfire.
It is relatively harmless, although it is very defensive of its nest site. I say 'nest site', but in truth, they have an unhealthy liking for previously occupied bird nest boxes and last year I was called to a ‘swarm’ of tree bumblebees that had colonised just such a nest box atop a bird feeding table.
That would be annoying enough on its own, but this particular cohort had picked a nest box in the garden of a residential home for adults with learning difficulties. Some of the residents were taking an unhealthy interest in the new attraction and so I was called in.
With their reputation of being very defensive, I was cautious, and there was no way they were going to be coaxed out of their bijou residence. So by mutual agreement, it was decided that as the nest box/bird table was in a bad state of repair, it would be best to remove the top section, complete with occupants.
After blocking the entrance with grass, a swift twist removed the nest box and it was transported back to spend the rest of the summer on the top of my woodshed. There the family lived out their natural lives and I could only presume that at the end of the summer, the new queens had gone off to hibernate underground somewhere, but I couldn't be sure – until this week.
Recently I was turning over my vegetable patch and removing the pernicious weeds when a tree bumblebee flew past. It landed at the base of a honeysuckle and stayed there for some considerable time. So they have survived the winter and since that day I have seen several more.
April announces the start of the beekeeping season and all my hives have successfully come through the winter. It has been particularly mild, but very wet and so all my hives contained parts that had become waterlogged. I have spent a few days doing necessary refurbishments and I have also coated them all in a dark green coating, so that they blend in better with their surroundings. All through the winter, I have been feeding them, to make amends for taking their honey, and, just to show me who is boss, they have consumed 100kgs of sugar!
Swarms of Bees
Beekeeping can cause a nuisance to the general public and the most likely way that it will happen is for a neighbour to get a swarm in their garden. Swarms occur mostly in April, May or June, with the larger ones earliest in the season. Swarms can be frightening because of the sheer mass of bees and the associated noise.
In truth, swarms are generally harmless, as the last thing that the bees do before they leave home, is to have an almighty feast of honey to ensure that they can survive until the new home is set up and they find where the food is. With their stomachs full of honey, it is almost impossible to bend their abdomen’s far enough forward to use their sting. Don’t take any chances though.
Swarming is the bees’ natural way of proliferating and is normally a sign of success for the bees, but not the beekeeper, who will go to great lengths to prevent a swarm, or control it so that the swarm can be retained to start a new colony. The bees decide to make a new queen and, once the cell containing the larvae of the new queen has been sealed to pupate, the reigning queen takes the hint and leaves with all the older bees - that is, those that can fly, because the younger bees don’t fly.
The old queen and old bees then set up a new home, but are really an older colony. When the new queen hatches in the original hive, she will take a mating flight and start on what could be a five-year life of laying eggs for the new colony. She can lay up to 2000 per day at the height of the season and at her peak.
What do I do if I find a swarm in my garden?
If you have a swarm, first establish that they are honeybees. Over 70% of all call outs to swarms are to bumblebee nests. There will be approximately 25,000 honeybees in a swarm. A bumblebee nest contains around 200 bees.
Next, don’t try to deal with it yourself and please don’t call the local pest controller. Most of them will not deal with a honeybee swarm anyway. Simply visit the British Beekeepers Association website and halfway down the page on the left-hand side it says ‘Do you have a swarm?’ Double click this and it will guide you through what to do.
Amateur beekeepers should not charge for removing swarms but may ask for expenses, if any are incurred. Remember, though, before you part with any ‘expenses’, that a viable and healthy swarm is worth quite a bit of money.
You shouldn't expect the beekeeper to buy the swarm from you. At the time of collection, the beekeeper has no idea if the queen is still with the swarm, if they have an aggressive temperament, or - much more importantly - if they are healthy. The swarm will have to be quarantined until their health is assured.
This is where I become unpopular with gardeners because one of the plants that bees appreciate most at this time of year is the humble dandelion (Taraxacum officinale). Yes, it may be the bane of the horticulturist’s existence... but the bees love it. By way of recompense, the bees will be all over the soft fruit blossoms, and red flowering currants (Ribes sanguineum) will be alive with bumblebees.