BBC Wildlife Magazine
BEES VS WASPS
Bees are basically vegetarian wasps. Way back in the Cretaceous, some solitary wasps made the transition from feeding their young on animal (usually insect) protein to feeding them on pollen, which is another good source of protein and energy. Bees are characterised by pollen-gathering adaptations, ‘pollen baskets’, often a scopa on the hind leg, or a specialised ventral surface of the abdomen. Bees also have branched setae (hairs), whereas these are simple in wasps. Another group of wasps, the pollen wasps, has also made the transition to feeding their young on pollen, though these still look typically waspy.
Some even exploit seasonally waterlogged soils, such as plasterer bees
– a group that line their nest cells with an impervious film, so thin and crinkly it earned them the nickname ‘cellophane bees’.
Members of the large leafcutter tribe often nest in rocky crevices or holes in wood, crafting individual cells from carefully snipped discs of foliage. Mason bees build chambers from mud and clay, while other species use flower petals, leaf hairs or sticky resin adorned with pebbles.
There are bees that nest in hollow twigs and some that prefer snail shells. The world’s largest bee, Wallace’s giant, lives only inside the nests of particular rainforest termites in Indonesia.
Homeowners across much of North America greet the arrival of carpenter bees with dismay, as they don’t build so much as tear down, excavating cavities in wood so large and numerous that whole structures have been known to collapse.
The story of bee diversity, or at least our understanding of that story, is still very much being written. That’s because the vast majority of species have never been studied in detail, and scientists believe that thousands remain yet to be discovered. But what we already know makes clear that wild bees are just as vital as honeybees, not only in natural areas but increasingly in agricultural systems, too.
Pollination by native bees increases the productivity of everything from soybeans and sunflowers to watermelons, and the hothouse tomato trade relies heavily on bumblebees. Orchardists now turn to mason bees to help pollinate apples, plums and peaches, while crops such as alfalfa rely almost exclusively on leafcutters and alkali bees. Research continues, but many farmers, gardeners, and backyard naturalists have begun taking steps to improve bee habitat.
If there is a silver lining to the challenges bees face in the modern world, it lies in our new-found curiosity about them. Because, to paraphrase Jane Goodall, curiosity leads to caring, and caring leads to help.
Wild bees are just as vital as honeybees – in natural areas and agricultural systems.