Cornish Bees? Yes, Please!

They’re the harbingers of spring, the hard-working sustainers of life, and the reason why plants evolved such breathtakingly beautiful flowers. Bees are abuzz all over Cornwall, and you may be greeting your black-and-gold garden visitors while wondering what type of bee they are.

The most classically known is of course the honeybee, such as those that recently alarmed citizens in Truro when they swarmed near a bus stop.1 That was actually a small swarm of only 15,000 bees, as wild honeybees live in large colonies that can be upwards of 50,000 bees!

A honeybee queen will live from 2 to 4 years depending on her health and good luck, while her workers will live for a few weeks or months only. A queen will mate with male drones immediately upon hatching and will begin producing thousands of eggs for the colony in which she was born, until after a year or two she produces a replacement queen.

By this point the colony will have grown so large that she will leave with a portion of the workers in a swarm in order to establish a new colony elsewhere. By the time she produces a young new queen for this second colony, she is likely getting old and unproductive, and either dies through disease or is very forcefully removed from office by her workers.

Honeybee colonies continue to store honey over the winter, and while their colony size is reduced in winter months, the queen does retain some workers to help her keep the nest running. In the spring, her production of eggs and workers increases substantially, and colony numbers boom into productivity for the duration of the summer.2

Brown-banded Carder Bumblebee_0.jpgBrown-banded Carder Bumblebee. Source: Nigel Jones/Flickr

Another important family of bees are the bumblebees. Sadly, Cornwall has lost one quarter of our bumblebees since the 20th century,3 but we still have a variety of species. We even have a few nationally important populations of rare species, such as the Brown-banded Carder Bumblebee (Bombus humilis).

The bumblebee life cycle is very different than that of a honeybee. A new bumblebee queen will mate with one male soon after she hatches at the end of the summer, and then she will go into hibernation overwinter. The following spring, she will emerge and begin to establish a colony. Unlike new honeybee queens, who begin their lives with an entourage of ready workers, the bumblebee queen must build a colony from scratch. She will construct wax cells in which to lay her eggs, as well as forage for food for herself and her developing brood.

Once the first batch of workers hatches, the queen’s life gets much easier as they take over the feeding and maintenance of the nest. Depending on the species, bumblebee colonies can contain anywhere from forty to a few hundred workers. Towards the end of the summer, the queen will begin laying males and new queens, which quickly scatter to find suitable non-related mates – and then the old queen will die, her life cycle completed when she is only one year old.2

Longhorn bee.jpgLonghorn Bee. Source: Will Hawkes

In addition to honeybees and bumblebees, Cornwall is also home to many kinds of solitary bees, such as the Longhorn Bee (Eucera longicornis) – a distinctive and charismatic Cornish native and one of the UK’s largest solitary bees.

Solitary bees, as their names suggest, do not form organized colonies, although they do sometimes form loose “neighbourhoods” by building nests close together. They do not make honey but feed their larvae nectar and pollen. Uniquely, solitary bees do not distinguish between “queens” and “workers” – all adult females are capable of reproducing, and each will find a male to mate with and then establish a small nest of eggs. While some species lay more eggs than others, none will ever approach the staggering numbers of honeybee colonies.

One of the most common types of solitary bees are mining bees, so called because their nests are actually tunnels in the soil that can have several branches (although nowhere near the type you’d find in ant colonies, for example). Some mining bees spend the winter as full-grown adults in hibernation, while others overwinter as larvae, but either way they will emerge as adults sometime in the spring when they will mate, build a nest, and lay their small brood of eggs. Adult mining bees have very brief lives and are only active for 6-8 weeks in the spring and summer. Then they die, leaving behind offspring that must hibernate and wait for the following year to emerge from their secure tunnels.4

Cornwall’s mining bee species include the Large Scabious Mining Bee (Adrena hattorfiana) and the Tormentil Mining Bee (Adrena tarsata), both of which are species of conservation concern. The Large Scabious Mining Bee has been declining across the UK, and in Cornwall has been limited to a couple of areas on the North Coast – populations which are divided from each other and therefore vulnerable.5 The rare Tormentil Mining Bee has also declined dramatically since the 1970s, but a population was re-discovered in Cornwall on the Bartinney Nature Reserve in 2014 that rekindled hope for the species’ local survival.6

Tormentil nomad bee.jpgTormentil Nomad Bee. Source: Will Hawkes

Finally, there are the “cuckoo” bees. They are not properly a single group, as there are cuckoo bumblebees, cuckoo mining bees, and even cuckoo wasps for that matter! Cuckoos will lay their eggs in the nests of another species, typically targeting one species in particular (for example, the Tormentil Nomad Bee (Nomada roberjeotiana) specifically parasitises nests of the Tormentil Mining Bee), and consume their host’s stores of nectar and pollen. They are difficult to conserve, as they rely entirely on a healthy population of their host species, which can itself be rare or struggling.

How to Help the Bees?

Unfortunately, wild bees in the UK face many challenges today, and Cornwall is no exception. The shocking decline of fields of wildflowers due to agricultural expansion is of course the most obvious culprit. The Cornish Red Data book, which keeps listings on species of conservation concern, writes that “Recreational and agricultural pressures over the past 30-40 years have, however, destroyed much key habitat for aculeates [bees and wasps]. The loss of sand dune habitat to car parking, golf courses, and holiday camps has been particularly damaging.”7 Clearly, when bee species depend on a single type of plant (such as tormentil or scabious) or on fragile habitat like moorland, conservation efforts become even more crucial.

There has lately been much-publicized concern about the declining health of bee populations worldwide, most notably when the EU upheld a ban on certain types of pesticides this past April.8 However, entomologists and bee experts have warned that the confusing message being sent to the general population conflates the commercial beekeeping industry with wild bee health, and also that pesticide usage is far from the only or even the biggest problem faced by wild bee populations.9

Commercially-kept honeybees are almost always shipped to beekeepers from elsewhere around the globe, and their populations are as controlled as any other livestock. Individual beekeepers choose to add to or reduce their hives in response to economic factors such as the price of honey, and it is normal to lose a certain percentage of hives each year. While industry practices are far from ideal and often unnecessarily stressful for bees, contributing to the collapsed hives that make the news, the fact remains that commercially farmed honeybees are in no danger of disappearing (despite the dire media hype).

Wild bees, on the other hand, face the loss of much of their diversity – and counterintuitively, the presence of beekeepers may be part of the problem. The beekeeping of non-native species can actually do more harm than good for wild populations. Infectious diseases like Deformed Wing Virus can spread from farmed bees to wild bees, and also farmed bees can overwhelm and outcompete local species for access to the few wildflowers that remain.  Hobby beekeepers may also be unsure how to treat for parasites or diseases in their hives. Both commercial beekeepers and those interested in hobby beekeeping would be wise to do careful research on the native bees in their area and thoughtfully consider the risks to their local environment.9

Large scabious mining bee.jpgLarge Scabious Mining Bee. Source: Will Hawkes

Yet there are many people and organisations devoted to safeguarding Cornwall’s fantastic biodiversity, including its buzzing bees. As the Cornish Red Data book writes, “Many areas of prime invertebrate habitat are now under protection by the creation of National Nature Reserves and SSSI [Sites of Special Scientific Interest]. The National Trust is also promoting the maintenance of species-rich habitat on its land. A prime area of aculeate habitat, on coastal dunes at Penhale is owned by the Ministry of Defence and is closed to the public.”7

The importance of protecting flower-rich grasslands, heath, and heather from agricultural or other development cannot be overstated. One Cornish native, the Longhorn Bee, has declined by 70% according to one report,10 likely due to the 97% reduction in flower-rich grassland in recent years.11 Other species have vanished completely from Cornwall – the Cornish Red Data Book writes that “many rare or scarce species of aculeates, once present, have not been re-found during the post-1980 period.”7

Thankfully, there are easy steps all of us can take to help our wild bee populations thrive. It is crucial for conservationists and scientists to monitor bee population and distributions, so remember to record your sightings with us here at ERCCIS using our ORKS website or APP. If you’re not sure which of our pollinating pals you’re looking at, we will be happy to help so send us your photographs. Plus, there are a variety of helpful ID guides available, such as Kernow Ecology’s free guide to Cornish bumblebees.3

Bees will also be appreciative (and your yard will be lovelier!) if you keep flowering plants in your garden year-round. Entomologists suggest growing heathers and willows in the early season, lavender and sweet peas in the mid-season, and Devil’s bit scabious and fuschia in the late season.9 Finally, be sure to express your support for conservation efforts to protect sensitive areas such as moorland, heathland, and wild grasslands. Maintaining these habitats will help many Cornish species thrive, including native bees.

So bee positive and spread the buzz about the bees!

Article by Caitlin Fikes, ERCCIS volunteer and University of Exeter student.

References:

  1. Vergnault, Olivier. “Swarm of 15,000 bees has bus passengers all abuzz as Truro park-and-ride calls for help.” CornwallLive, 24 May 2018.
  2. https://www.buzzaboutbees.net/beelifecycle.html
  3. Saunders, Patrick. “Bumblebees of Cornwall and Scilly.” Kernow Ecology & ERCCIS, 2016. http://kernowecology.co.uk/Bumblebees%20of%20Cornwall.pdf
  4. https://www.buzzaboutbees.net/mining-bees.html
  5. Hawkes, Will. “South West Bees Project: Andrena hattorfiana in Cornwall.” BugLife.org.uk, 2016
  6. “Two rare bee species discovered on Cornwall nature reserve.” BBC, 12 September 2014
  7. Gainey, P.A. “Aculeates (In Part).” Cornish Red Data Book, http://www.cisfbr.org.uk/CRDB/StartCRDB.htm
  8. Carrington, Damian. “EU agrees total ban on bee-harming pesticides.” The Guardian, 27 April 2018.
  9. Hawkes, Will. “The Wild Bees and Other Forgotten Pollinators.” Spring 2018
  10. Kernow Ecology: Invertebrate Survey and Conservation http://kernowecology.co.uk/eucera.html
  11. “Species Management Sheet: Long-horned bee (Eucera longicornis)” BugLife.co.uk