The little plastic envelope contained a very dead bumblebee. A friend had found it on her windowsill, and wondered if it could be a tree bumblebee, a new species to Britain, coming from the Continent and extending its range rapidly northward. I consulted a WNS member who’s been doing a study of her garden bumblebees, and the answer was – yes. A tree bumblebee is actually quite easy to identify: it has a cheerful yellow thorax, dark abdomen and small whitish tail – a unique combination. Unlike other invading creatures, like mink or signal crayfish, it offers no threat to our native wildlife. In fact it’s rather welcome as another useful pollinator at a time when honeybees are declining. Tree bumblebees get their name from their habit of building their nests in tree-holes; now they’ve explored other possibilities. One of our members put up a number of holed footballs as nest boxes at the Otley Wetlands Reserve and one of these has been taken over by tree bumblebees and now houses a thriving colony.
As a result of all this information, last week I could be seen standing stock still in our driveway staring fixedly at the clumps of marjoram which fringe it. Insects love the mauve flowers and I enjoy watching them – iridescent flies like tiny jewels, hoverflies pausing and then descending to feed, a good showing of honeybees and, of course, lots of bumblebees. The most common species in our garden are buff-tailed (handsome yellow bands), white-tailed (more lemon-yellow bands and cleaner white tail), red-tailed bumblebee, garden bumblebee (long-legged and long face) and the all-brown common carder bee. And there are others – and also cuckoo bees (not bees at all). These sneaky characters mimic the colour patterns of the bumblebee species they prey on, kill the host queen, lay eggs in her nest and leave the young to be fed by the host workers. They can be distinguished by the shiny black abdominal plates showing through their sparser fur. It’s a whole new world out there among the marjoram! Easy-to-use digital cameras have made bee-study much simpler. Personally, I don’t worry too much about individual identification – I just enjoy seeing how many differently patterned insects I can count, by comparing the various combinations of colour bands.
I seriously recommend this approach as an introduction to natural history for your children or grandchildren. It sharpens the eyes to detect subtle differences and appeals to a child’s natural appetite for scoring and competition! I used it myself for another potentially tricky identification group. Last week as I sauntered along a track bordered with banks of flowers – tormentil, thistles, birds’-foot trefoil, knapweed and drifts of harebell, I gave up on the butterflies – too windy – and concentrated on the grasses. In about 150 yards I collected a bunch of grass seedheads that, on closer inspection, included ten easily differentiated species. Of course, you can go further and start the naming process. And what lovely names – timothy, cocksfoot, foxtail and, of course, Yorkshire fog.